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Klinische Studien zur konservierenden Zahnheilkunde mit dem Dental-Laser

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Hypersensitivity URL  Adu-Arko, A.Y., Sidhu, SK, McCabe, JF and Pashley, DH Effect of an Er,Cr:YSGG laser on water perfusion in human dentine European Journal of Oral Sciences
Vol. 118, pp. 483-488 
2010 rank3
Abstract: Changes in fluid perfusion through tubules may affect the sensitivity of exposed and restored dentine. The rate of perfusion is dependent on the structure and composition of dentine, particularly at the surface. This work analyzed the effect of treatment with an Erbium, Chromium-doped: Yttrium Scandium Gallium Garnet (Er,Cr:YSGG) laser on dentine perfusion. Extracted molars were sectioned above the mid-coronal portion, and below the cemento-enamel junction, to create crown segments. The pulp was extirpated and the dentine treated with the Er,Cr:YSGG laser, a diamond bur or sandpaper. Each specimen was mounted, with the pulp chamber oriented upwards, on a petri-dish cover in order to permit a tube filled with water to be connected to the pulp. Movement of the water meniscus over 24 h provided a measurement of the volume of water that filtered across the dentine. The dishes contained water to provide a moist environment in the relevant specimens, or were left dry to provide dry conditions. Specimens were perfused for 24 h with water pressures ranging from 20 to 60 cm. The results (in μl mm(-2) d(-1) ) showed a significant difference in the perfusion rate between treatments. The difference between perfusion in wet and dry conditions was highly significant. Laser and bur treatment of dentine significantly affected perfusion, which was higher in the former than in the latter. Therefore, laser-treated dentine may be more sensitive than bur-cut dentine.
Bonding URL  Al-Omari, W., Palamara, J. and Almohammed, S. The effect of laser irradiation on retention of full cast crowns The European journal of prosthodontics and restorative dentistry
Vol. 21(1), pp. 34-39 
2013 rank3
Abstract: The objective of this work was to determine the effect on the retention force of full cast crowns cemented on short tooth preparations after preparation of dentine with an erbium, chromium: yttrium scandium gallium garnet (Er, Cr:YSGG) laser at different sub-ablative power settings. Thirty teeth were prepared for full cast crowns using a milling machine. The surface area for all preparations was measured. The surfaces of the preparations were irradiated with 0 (control), 0.25 and 0.75 W laser. The crowns were cemented with self-cure resin cement and tested for retention on a Hounsfield Tensometer machine. The 0.75 W power setting produced the highest failure load value (346.2 +/- 86.1 N) and was significantly higher than the other groups. There were no significant differences between the 0.25 W and 0 W control groups
Microstructure / Mineral Content DOI URL  Al-Omari, W.M. and Palamara, J.E. The effect of Nd:YAG and Er,Cr:YSGG lasers on the microhardness of human dentin Lasers in Medical Scienceer  2012 rank1
Abstract: The current investigation determined the microhardness of dentin tissue irradiated with erbium, chromium-doped yttrium scandium gallium garnet (Er,Cr:YSGG) and neodymium-doped yttrium-aluminum garnet (Nd:YAG) lasers. Thirty non-carious human molars were used in this study. Dentin disks were prepared by horizontal sectioning of one third of the occlusal surface. Halves of dentin specimens were irradiated with 3.5- and 4.5-W Er,Cr:YSGG lasers and with a 2-W Nd:YAG laser. The remaining halves served as controls. The microhardness measurements were recorded with a Vickers surface microhardness tester. The results were statistically evaluated by paired t test and one-way ANOVA (p = 0.05). Laser irradiation has significantly reduced the microhardness of dentin within each group compared to its control. Moreover, statistically significant differences were observed among the different groups (p < 0.05). The 3.5-W Er,Cr:YSGG laser produced the greatest reduction in microhardness of dentin followed by 4.5 W and Nd:YAG laser. The differences between all the groups were statistically significant. It was concluded that both laser devices used in this study have resulted in significant thermal damage and subsequent reduction in dentin microhardness values.
Demineralization DOI URL  Ana, P., Tabchoury, C., Cury, J. and Zezell, D. Effect of Er,Cr:YSGG laser and professional fluoride application on enamel demineralization and on fluoride retention Caries research
Vol. 46(5), pp. 441-451 
2012 rank3
Abstract: This section lists publications related to constructivist approaches – constructivism, second-order cybernet- ics, enaction, non-dualism, biology of cognition, neurophenomenology etc. – that recently have been published else- where, and which the reader of the journal might find interesting. The entries are ordered alphabetically and clustered according to their respective primary disciplinary backgrounds or application. The increasingly extending bibliography and the Constructivist E-Print Archive (CEPA) can be consulted at http://cepa.info
Demineralization URL  Apel, C., Schafer, C. and Gutknecht, N. Demineralization of Er:YAG and Er,Cr:YSGG laser-prepared enamel cavities in vitro Caries research
Vol. 37, pp. 34-37 
2003 rank3
Abstract: The aim of the present study was to establish whether cavity preparation by means of an erbium laser with efficient water cooling is capable of reducing the susceptibility of the prepared dental enamel to demineralization and thus of achieving a potential caries-protective effect in the region of cavity margins. To this end, cavities limited to the enamel were prepared in the crowns of 10 teeth each using an Er:YAG (lambda = 2,940 nm) and an Er,Cr:YSGG laser (lambda = 2,780 nm). A control cavity prepared conventionally with a diamond drill in the same occlusal zone was assigned to each of these cavities. The specimens were then subjected to a pH-cycling caries model. Analysis was performed by quantitatively measuring the demineralization front under a polarized-light microscope. The results of the study showed that enamel cavities prepared with the erbium lasers used display a statistically significant acceleration of demineralization compared to conventionally prepared cavities (p < 0.01). The Er:YAG laser cavities revealed demineralization to a depth of 133.9 (SD 25.7) microm, while the value observed with the Er,Cr:YSGG laser was 133.8 (SD 25.8) microm. The depth of demineralization in the control groups was only 77.4 (SD 13.8) microm and 79.3 (SD 37.6) microm. No difference could be found between the two lasers (p = 0.98). Based on these in vitro tests, it cannot be assumed that use of the erbium laser for cavity preparation offers any advantages in terms of resistance to secondary caries in clinical practice.
Hypersensitivity URL  Aranha, A. and Eduardo, C.P. Effects of Er:YAG and Er,Cr:YSGG lasers on dentine hypersensitivity. Short-term clinical evaluation Lasers in Medical Science
Vol. 27, pp. 813-818 
2012 rank4
Abstract: Dentine hypersensitivity (DH) is a painful condition and is a clinical challenge due to the different treatment strategies available. High-intensity lasers have been studied as a possible option. The aim of this randomized, controlled, double-blind clinical study was to evaluate the effects of Er:YAG and Er,Cr:YSGG lasers on DH. The study group comprised 28 subjects who met the inclusion criteria. A visual analogue scale was used to quantify sensitivity before treatment as baseline, immediately before and immediately after treatment, and 1 week and 1 month after treatment. Teeth were assigned to four groups: group 1 control (no treatment), group 2 Er:YAG laser treatment (2 Hz/32.4 mJ/5.9 J/cm(2)), group 3 Er,Cr:YSGG laser treatment (0.25 W/4.4 J/cm(2)), and group 4 Er,Cr:YSGG laser treatment (0.50 W/ 8.9 J/cm(2)). Data were collected and submitted to statistical analysis for both evaporative (air) and mechanical (probe) stimulation. For both the air and probe stimulation no differences were observed between the pretreatment sensitivities. With the evaporative stimulus, the pain level immediately after treatment was reduced; however, after this the values remained stable. Irradiation with the Er:YAG laser was associated with the lowest level of pain. With the mechanical stimulus, group 4 showed the most pronounced decrease in pain immediately after treatment; however, by the end of the study, pain levels had increased. Groups 1, 2 and 3 showed a reduction in pain that was significantly different from that in group 4 after the 4 weeks of clinical follow up. Based on the results and within the limits of this study, it can be concluded that none of the laser treatments studied was capable of completely eliminating pain, but the Er:YAG and Er,Cr:YSGG lasers are suitable for the treatment of DH.
Hypersensitivity DOI   Aranha, A.C.C. and Eduardo, C.D.P. In vitro effects of Er,Cr:YSGG laser on dentine hypersensitivity . Dentine permeability and scanning electron microscopy analysis Lasers in Medical Science
Vol. 27(4), pp. 827-834 
2011 rank4
Abstract: The aim of the present study was to determine clinical parameters for the use of Er,Cr:YSGG laser in the treatment of dentine hypersensitivity. Two antagonist areas were determined as control and experimental areas for irradiation in 90 premolar roots. Each surface was condi- tioned with 24% EDTA (sub-group 1) and 35% phosphoric acid (sub-group 2) and irradiated with the following settings: 1) Er:YAG, 60 mJ, 2 Hz, defocused; groups 2 to 9: irradiation with Er,Cr:YSGG laser, 20 Hz, Z6 tip, 0% of air and water: 2) Er,Cr:YSGG0.25W; 3) 0.5W; 4) 0.75W; 5) 1.0W; 6) 1.25W, 7) 1.50W, 8) 2W; 9) 2W. After irradiation, samples were immersed in methylene blue solution and included in epoxy resin to obtain longitudinal cuts. The images were digitalized and analyzed by computer software. Although the samples irradiated with Er:YAG laser showed less microleakage, sub-group 1 showed differences between the groups, differing statistically from groups 3, 6, and 9. The results of sub-group 2 showed that the mean values ofEr:YAG samples showed a negative trend, however, no differences were detected between the groups. For scanning electron microscopy analysis, dentine squares were obtained and prepared to evaluate the superficial morphology. Partial closure of dentinal tubules was observed after irradiation with Er:YAG and Er,Cr:YSGG laser in the 0.25 and 0.50 W protocols. As the energy densities rose, open dentinal tubules, carbonization and cracks were observed. It can be concluded that none of the parameters were capable of eliminating microleakage, however, clinical studies with Er:YAG and Er,Cr:YSGG lasers should be conducted with the lowest protocols in order to determine the most satisfactory setting for dentine hypersensitivity.
Restorative URL  Ayar, M., Yesilyurt, C., Yildirim, T. and Erdermir, F. Bonding Strength of Universal Adhesives To Er,Cr:YSGG Laser-Irradiated Dentin Nigerian Journal of Clinical Practice
Vol. 21(1), pp. 93-98 
2018 rank3
Abstract: Objectives: Universal adhesives have been recently introduced for use as self-etch or etch-and-rinse adhesives depending on the dental substrate and clinical condition. However, their bonding effectiveness to laser-irradiated dentin is still not well known. Therefore, the aim of this study was to compare the shear bond strength (SBS) of two universal adhesives (Single Bond Universal, Nova Compo-B Plus) applied following laser-etching with SBS of the same adhesives applied in self- etch and acid-etch modes, respectively. Materials and Methods: Sixty bovine incisors were used to obtain the flattened dentin surfaces. Specimens were divided into two groups according to universal adhesives. Each universal adhesive was applied with one of the following modes, self-etch, acid-etch, or laser-etch (n = 10). Er,Cr:YSGG laser was used for laser-etching with 1.5 W–20 Hz parameters. After adhesive applications and composite buildups, SBS was determined after storage in water for 24 h using a universal testing machine with a crosshead speed of 0.5 mm/min. Failure modes were evaluated using a stereomicroscope. Data were analyzed using two-way of analyses of variances (ANOVA) (P = 0.05). Results: Two-way ANOVA revealed that adhesive had no effect on SBS (P > 0.05), but application mode significantly influenced SBS (P < 0.001). Laser-etch significantly increased SBS for NCP when compared to self-etch mode, whereas laser-etch provided similar SBS with self-etch mode for SBU. Conclusions: The influence of different application modes on dentin bond strength of universal adhesives was dependent on the adhesive material. Clinical Significance: For universal adhesives, laser etching may provide some benefits on bonds strength but this would depend on product.
Restorative DOI   Bağlar, S. Sub-ablative Er,Cr:YSGG laser irradiation under all-ceramic restorations: effects on demineralization and shear bond strength Lasers in Medical Science
Vol. 33(1), pp. 41-49 
2018 rank5
Abstract: This study evaluated the caries resistant effects of sub-ablative Er,Cr:YSGG laser irradiation alone and combined with fluoride in comparison with fluoride application alone on enamel prepared for veneer restorations. And also, evaluated these treatments' effects on the shear bond strength of all-ceramic veneer restorations. One hundred and thirty-five human maxillary central teeth were assigned to groups of 1a–control, 1b–laser treated, 1c–fluoride treated, 1d–laser + fluoride treated for shear bond testing and to groups of 2a–positive control(non-demineralised), 2b–laser treated, 2c–fluoride treated, 2d–laser + fluoride treated, 2e–negative control (demineralised) for microhardness testing (n = 15, N = 135). Demineralisation solutions of microhardness measurements were used for the ICP-OES elemental analysis. The parameters for laser irradiation were as follows: power output, 0.25 W; total energy density, 62.5 J/cm2 and energy density per pulse, 4.48 J/cm2 with an irradiation time of 20 s and with no water cooling. Five percent NaF varnish was used as fluoride preparate. ANOVA and Tukey HSD tests were performed (α = 5%). Surface treatments showed no significant effects on shear bond strength values (p = 0.579). However, significant differences were found in microhardness measurements and in elemental analysis of Ca and P amounts (p < 0.01). Surface-treated groups showed significantly high VNH values and significantly low ICP-OES values when compared with non-treated (−control) group while there were no significance among surface-treated groups regarding VHN and ICP-OES values. Sub-ablative Er,Cr:YSGG treatment alone or combined with fluoride is as an effective method as at least fluoride alone for preventing the prepared enamel to demineralization with no negative effect on shear bond strength. textcopyright 2017 Springer-Verlag London Ltd.
Bonding DOI   Baygin, O., Korkmaz, F.M., Tüzüner, T. and Tanriver, M. The effect of different enamel surface treatments on the microleakage of fissure sealants Lasers in Medical Science
Vol. 27(1), pp. 153-160 
2012 rank4
Abstract: The aim of this study was to evaluate the effects of different techniques of surface treatment on the microleakage of a fissure sealant in molar teeth. A total of 50 freshly extracted noncarious human third molars were randomly assigned to one of five groups. Occlusal fissures were treated with one of the following: acid etching with 35% orthophosphoric acid (group 1); fissurotomy with a Fissurotomy Micro NTF metal bur (group 2); laser etching with an Er,Cr:YSGG laser at 2 W and 20 Hz (group 3); laser etching with an Er,Cr:YSGG laser at 2 W and 40 Hz (group 4); and air abrasion for 20 s with 30-µm Al(2)O(3) particles via a CoJet Prep device (group 5). After surface pretreatment, a resin-based sealant was applied to the fissures. The sample teeth were subjected to thermocycling and stored in distilled water at 37°C for 1 month. Following immersion in 0.5% basic fuchsin solution for 24 h, three buccolingual slices of each sample tooth were scored under a stereomicroscope, and the morphological appearance of the area between the enamel surface and fissure sealant was examined under a scanning electron microscope. The Kruskal-Wallis test and one-way ANOVA revealed significant differences in marginal leakage, as follows: group 1 showed significantly lower scores than groups 2 and 5, the scores of groups 1, 3 and 4 were not significantly different, and group 2 showed significantly higher scores than groups 3 and 4. Laser irradiation, the metal bur, and the CoJet Prep device did not eliminate the need for acid etching of the enamel prior to placement of a fissure sealant. Laser etching at 2 W (20 Hz or 40 Hz) may be an alternative to conventional acid-etching.
Restorative DOI URL  Botta, S.B., Ana, P.A., de Sa Teixeira, F., da Silveira Salvadori, M.C.B. and Matos, A.B. Relationship between surface topography and energy density distribution of Er,Cr:YSGG beam on irradiated dentin: an atomic force microscopy study. Photomedicine and laser surgery
Vol. 29(4), pp. 261-9 
2011 rank1
Abstract: OBJECTIVE: The aim of this study was to assess by atomic force microscopy (AFM) the effect of Er,Cr:YSGG laser application on the surface microtopography of radicular dentin.n Lasers have been used for various purposes in dentistry, where they are clinically effective when used in an appropriate manner. The Er,Cr:YSGG laser can be used for caries prevention when settings are below the ablation threshold.nnMATERIALS AND METHODS: Four specimens of bovine dentin were irradiated using an Er,Cr:YSGG laser (λ = 2.78 μm), at a repetition rate of 20 Hz, with a 750-μm-diameter sapphire tip and energy density of 2.8 J/cm(2) (12.5 mJ/pulse). After irradiation, surface topography was analyzed by AFM using a Si probe in tapping mode. Quantitative and qualitative information concerning the arithmetic average roughness (Ra) and power spectral density analyses were obtained from central, intermediate, and peripheral areas of laser pulses and compared with data from nonirradiated samples.n Dentin Ra for different areas were as follows: central, 261.26 (±21.65) nm; intermediate, 83.48 (±6.34) nm; peripheral, 45.8 (±13.47) nm; and nonirradiated, 35.18 (±2.9) nm. The central region of laser pulses presented higher ablation of intertubular dentin, with about 340-760 nm height, while intermediate, peripheral, and nonirradiated regions presented no difference in height of peritubular and interperitubular dentin.n According to these results, we can assume that even when used at a low-energy density parameter, Er,Cr:YSGG laser can significantly alter the microtopography of radicular dentin, which is an important characteristic to be considered when laser is used for clinical applications.
Bonding URL  Cehreli, S.B., Gungor, H.C. and Karabulut, E. Er,Cr:YSGG laser pretreatment of primary teeth for bonded fissure sealant application: a quantitative microleakage study. Journal of Adhesive Dentistry
Vol. 8(6), pp. 381-386 
2006 rank1
Abstract: PURPOSE: Laser pretreatment of dental hard tissues prior to preventive or restorative procedures has been a subject of research. Unground primary enamel bears a prismless superficial layer which is known to be acid resistant. This in vitro study was conducted in order to evaluate the potential use of Er,Cr:YSGG laser in the pretreatment of occlusal surfaces of primary teeth prior to bonded fissure sealant application.MATERIALS AND METHODS: Occlusal surfaces of human primary mandibular molars were used (n =140). After pretreatment with Er,Cr:YSGG laser (group A) or not (group B), occlusal fissures were treated with one of the following in each of 7 subgroups (n = 10): 1. phosphoric acid-etch only; 2. Clearfil SE Bond; 3. FL Bond; 4. Adper Prompt L-Pop; 5. NRC+Prime & Bond NT; 6. One-Up Bond F; 7. Xeno III. All teeth were sealed with Fissurit F. The specimens were thermocycled (1000 times) and stored thereafter in distilled water at 37 degrees C for 8 months. Following immersion in 0.5% basic fuchsin solution, three bucco-lingual sections were made from each tooth. They were digitally photographed and the extent of dye penetration along the enamel-sealant interface was measured (in mm) with image analysis software.RESULTS: There was no difference between the Er,Cr:YSGG laser pretreated group (group A) and the nonlased grou (group B) (p > 0.05). The lowest microleakage values were observed in subgroups A1 and B1. Within the laser pretreated group, subgroups A1, A4, and A5 showed lower microleakage scores when compared to subgroups A2, A3, A6, and A7 (p < 0.05). As for the nonlased group, subgroups B1, B3, B4, and B5 demonstrated significantly lower microleakage scores than subgroups B2, B6, and B7 (p < 0.05).CONCLUSION: Er,Cr:YSGG laser pretreatment was not found to influence the resistance to microleakage of bonded fissure sealant application in primary teeth
Microstructure / Mineral Content DOI   Çelik, E., Ergücü, Z., Türkün, L. and Türkün, M. Effect of Different Laser Devices on the Composition and Microhardness of Dentin Operative Dentistry
Vol. 33(5), pp. 496-501 
2008 rank1
Abstract: This study determined the compositional changes and microhardness of the cavity floor prepared by Er, Cr:YSGG and Er:YAG lasers and compared the results with the conventional method of bur preparation. Fifteen non-carious human molars were used in this study. On the buccal and lingual surfaces of each tooth, two cavities (mesio-distal 3 mm, inciso-gingival 3 mm, depth 2 mm) were prepared with two different laser devices (Er, Cr:YSGG laser; Waterlase MD and Er:YAG laser; KaVo Key Laser 3) and a high-speed turbine. The teeth were embedded into polyester resin and cross-sectioned. The micro-hardness measurements from the floor of each half cavity were recorded with the Vickers surface hardness tester. The remaining halves of the cavities were subjected to SEM-EDS atomic analysis. The results were statistically evaluated by one-way ANOVA and Kruskal Wallis tests (p=0.05). No significant differences were observed among the microhardness values, quantities of Ca (Ca weight %), P (P weight %) and Ca/P ratio of the lased and conventionally prepared cavities (p>0.05). The cavity preparation techniques and differences in laser devices did not significantly alter the composition and microhardness of dentin tissue. Both laser devices used in this study were observed to lead to minimal thermal damage in the dentin tissue and minimal thermally-induced changes in dentinal compositions.
Hypersensitivity DOI   Chandavarkar, S. and Ram, S. A comparative evaluation of the effect of dentin desensitizers on the retention of complete cast metal crowns Contemp Clin Dent
Vol. 6(1), pp. S45-S50 
2015 rank1
Abstract: Context: Desensitizers are used to reduce dentin hypersensitivity. They affect the surface texture of prepared dentin and may alter the retention of fixed restorations. Aims: The aim was to evaluate the effect of dentin desensitizers on the retention of complete cast metal crowns luted with glass ionomer cement. Subjects and Methods: Fifty freshly extracted human premolars were subjected to standardized tooth preparation (20° total convergence, 4 mm axial height) with a computer numerically controlled machine. Individual cast metal crowns were fabricated from a base metal alloy. Dentin desensitizers included none (control), a glutaraldehyde (GLU) based primer (Gluma desensitizer), casein phosphopeptide (CPP)-amorphous calcium phosphate (ACP) (GC Mousse), erbium, chromium: YSGG laser (Waterlase MD Turbo, Biolase) and Pro-Argin (Colgate Sensitive Pro-Relief desensitizing polishing paste). After desensitization, crowns were luted with glass ionomer cement and kept for 48 h at 37°C in 100% relative humidity. The samples were tested using a universal testing machine by applying a load at a crosshead speed of 0.5 mm/min. Statistical Analysis Used: Statistical analysis included One-way ANOVA, followed by the Scheffe post-hoc test with P < 0.05. Results: All dentin desensitizers showed significantly different values: Pro-Argin (4.10 Megapascals [Mpa]) < CPP-ACP (4.01 mpa) < GLU based primer (3.87 Mpa) < Virgin dentin (3.65 Mpa) < LASER (3.37 Mpa). Conclusions : On comparing the effect of prepared virgin dentin, GLU based primer, CPP-ACP, LASER and Pro-Argin on the retention of complete cast metal crowns luted with glass ionomer cement on prepared teeth, it can be concluded that Pro-Argin and CPP-ACP showed the best retention in this in vitro study.
Bonding URL  Chou, J.-C., Chen, C.-C. and Ding, S.-J. Effect of Er,Cr:YSGG laser parameters on shear bondstrength and microstructure of dentine Photomedicine and laser surgery
Vol. 27(3), pp. 481-486 
2009 rank4
Abstract: OBJECTIVE:
The objective of this study was to investigate the effect of different Er,Cr:YSGG laser parameters on the morphology of irradiated dentine and the shear bond strength between resin composites and irradiated dentine.
MATERIALS AND METHODS:
Dentine specimens prepared from extracted human third molars were randomly assigned to six groups, including one receiving phosphoric acid etching, and five others with different laser parameters: 5 W for 30 sec, 2.5 W for 30 sec, 2.5 W for 60 sec, 1.5 W for 30 sec, and 1.5 W for 100 sec. Surface morphology was examined using a scanning electron microscope (SEM). Average roughness (Ra) was determined with a profilometer. Bonding of resin composites to the dentine specimens was tested in shear mode.
RESULTS:
The dentine surfaces irradiated by the Er,Cr:YSGG laser showed a scaly and rugged appearance and open dentinal tubules without smear layer production. The 5-W-irradiated group had the highest roughness value (p < 0.05). One-way ANOVA revealed that the shear bond strength of resin composites to the laser-irradiated dentine ranged from 12.35-15.61 MPa, and was not significantly (p > 0.05) different from the bond strength seen in the acid-etched dentine of 19.06 MPa. However, the surface roughness of the laser-irradiated dentine was significantly (p < 0.05) higher than that of the acid-etched dentine.
CONCLUSIONS:
The 5-W power setting may be suitable for dental restoration applications in terms of shear bond strength and activation area.
Bonding DOI URL  Cvikl, B., Moser, G., Wernisch, J., Raabe, M., Gruber, R. and Moritz, A. The impact of Er,Cr:YSGG laser on the shear strength of the bond between dentin and ceramic is dependent on the adhesive material Lasers in medical science
Vol. 27(4), pp. 717-722 
2012 rank3
Abstract: The bond joint between dentin and ceramic is a critical determinant in prosthodontic dentistry. The laser is an alternative to the diamond bur for preparing tooth cavities. However, the impact of lasers on the bond between the laser-irradiated dentin and the ceramic remains a matter of controversy. We determined the shear strength of bonds between ceramic blocks and human dentin discs prepared with either an Er,Cr:YSGG laser or a diamond bur. A total of 180 dentin discs were randomly assigned to four groups. Three groups of discs were prepared with the Er,Cr:YSGG laser irradiation (2 W, 30 Hz, 50% H(2)O, 70% air) and the fourth group was prepared with a diamond bur. In one of the laser groups the discs surfaces were also treated with phosphoric acid and in another with phosphoric acid and mechanical smoothing using a dental excavator. The ceramic blocks were bonded to the dentin discs with Syntac adhesive (together with Variolink II curing system), ExciTE adhesive (together with Variolink II curing system) or RelyX self-adhesive cement. The shear strength of the bond between ceramic and dentin was significantly higher following dentin surface treatment with the laser alone than following treatment with the diamond bur and Variolink II/Syntac (p = 0.021) but not significantly higher than following treatment with the diamond bur and Variolink II/ExciTE (p = 0.138) or RelyX (p = 0.150). A significant difference was not observed when the laser-treated dentin was conditioned with phosphoric acid and mechanical smoothing. These findings demonstrate that the bond between dentin and ceramic may be stronger after laser irradiation; however, the selection of the adhesive material is an additional factor that affects the bond strength.
Bonding DOI URL  De Moor, R.J.G. and Delme, K. Laser-assisted Cavity Preparation and Erbium-lased Tooth Structure: Part 1. Laser-assisted Cavity Preparation Journal of Adhesive Dentistry
Vol. 11, pp. 427-438 
2009 rank1
Abstract: The use of the ruby laser (693.4 nm) was first described in 1960, and it was applied for hard tissue abla- tion in 1964. Different wavelengths [Nd:YAG (1.065 µm), CO2 (9.6 µm), Ho:YAG (2.12 µm)] were consequently ex- plored. Due to massive thermal side effects, these wavelengths caused increased temperature in dental pulp, as well as microcracks and carbonization. The use of this laser for dental hard tissue preparation was eventually abandoned. At the end of the 1980s, excimer lasers (ultraviolet) and the erbium laser (infrared) were developed, with the advan- tages of improved temperature control and smaller penetration depths. With the development of smaller devices and improved knowledge of how to limit damage to the surrounding tissues, new ablation techniques were established in the 1990s. There is still contradiction in the current literature, however, in that different wavelengths are advocated for hard tissue removal, and heterogeneity in laser parameters and power densities remain. In this review, the effects of the wavelengths presently used for cavity preparation are evaluated. We conclude that erbium lasers (Er:YAG and Er,Cr:YSGG) are most efficient and, with the right parameters, the thermal side effects are small. There is a substan- tial need for “gold standards”, although this is difficult to establish in practice owing to different laser parameters (in- cluding pulse repetition rate, amount of cooling, energy delivered per pulse, and types of pulses) and target specificity (tissue interaction with sound or decayed enamel or dentin, and the extent of (de)mineralization) which in- fluence tissue interaction
Bonding DOI   Eduardo, C.D.P., Bello-Silva, M.S., Moretto, S.G., Cesar, P.F. and De Freitas, P.M. Microtensile bond strength of composite resin to glass-infiltrated alumina composite conditioned with Er,Cr:YSGG laser Lasers in Medical Science
Vol. 27(1), pp. 7-14 
2012 rank2
Abstract: Tribochemical silica-coating is the recommended conditioning method for improving glass-infiltrated alumina composite adhesion to resin cement. High-intensity lasers have been considered as an alternative for this purpose. This study evaluated the morphological effects of Er,Cr:YSGG laser irradiation on aluminous ceramic, and verified the microtensile bond strength of composite resin to ceramic following silica coating or laser irradiation. In-Ceram Alumina ceramic blocks were polished, submitted to airborne particle abrasion (110 μm Al(2)O(3)), and conditioned with: (CG) tribochemical silica coating (110 μm SiO(2)) + silanization (control group); (L1-L10) Er,Cr:YSGG laser (2.78 μm, 20 Hz, 0.5 to 5.0 W) + silanization. Composite resin blocks were cemented to the ceramic blocks with resin cement. These sets were stored in 37°C distilled water (24 h), embedded in acrylic resin, and sectioned to produce bar specimens that were submitted to microtensile testing. Bond strength values (MPa) were statistically analyzed (α ≤0.05), and failure modes were determined. Additional ceramic blocks were conditioned for qualitative analysis of the topography under SEM. There were no significant differences among silicatization and laser treatments (p > 0.05). Microtensile bond strength ranged from 19.2 to 27.9 MPa, and coefficients of variation ranged from 30 to 55%. Mixed failure of adhesive interface was predominant in all groups (75-96%). No chromatic alteration, cracks or melting were observed after laser irradiation with all parameters tested. Surface conditioning of glass-infiltrated alumina composite with Er,Cr:YSGG laser should be considered an innovative alternative for promoting adhesion of ceramics to resin cement, since it resulted in similar bond strength values compared to the tribochemical treatment.
Microstructure / Mineral Content DOI   Ekworapoj, P., Sidhu, S.K. and McCabe, J.F. Effect of different power parameters of Er,Cr:YSGG laser on human dentine Lasers in Medical Science
Vol. 22, pp. 175-182 
2007 rank1
Abstract: The aim of this work was to determine the optimal power setting of an Er,Cr:YSGG laser for cutting human dentine to produce a surface that remains suitable as a foundation on which to build and bond a dental restoration. The cutting efficiency and resulting microhardness of the dentine were evaluated for various laser power settings, and representative samples were examined by SEM. The microhardness of the dentine was significantly reduced by 30–50% (p < 0.05, paired t test) after laser irradiation, irrespective of the power setting used. The mean ablation efficiency increased in proportion to the power setting of the laser. Although the laser power setting did not affect the extent of reduction in microhardness, it did affect the microstructure of human dentine.
Deciduous URL  Eren, F., Altinok, B., Ertugral, F. and Tanboga, I. The effect of Er,Cr:YSGG laser therapy on pain during cavity preparation in paediatric dental patients: A pilot study OHDM
Vol. 12(2), pp. 80-84 
2013 rank3
Abstract: INTRODUCTION:
Standard treatment for caries removal and cavity preparation for restorations using mechanical means is often accompanied by fear and pain for the patient. Although the pain may be reduced by local anaesthesia, fear of the needle, noise, and the vibration of mechanical preparation remain a cause of discomfort. Erbium, chromium:yttriumscandium- gallium-garnet (Er,Cr:YSGG) laser irradiation indicates that pain perception may be reduced relative to that caused by mechanical preparation.
AIM:
The aim of this pilot clinical study was to perform a preliminary evaluation of pain perception during cavity preparation comparing the mechanical removal and Er,Cr:YSGG laser removal of caries from enamel and dentine.
METHODS:
The study sample was ten children aged 7 to 12 years. Half of the preparations were completed by the laser alone and the other half were mechanically prepared. All cavities were restored with light-cured composite resin following the application of acid etch and a bonding agent. The time spent on cavity preparation and the behaviour of the patients during cavity preparation were recorded. Children were instructed to rate their pain on a visual analogue scale. In addition, the patients were asked to decide which was the more uncomfortable form of treatment and the preferred treatment for future caries therapy.
RESULTS:
Children showed considerably more body and head movement with the conventional mechanical preparation. The subjects rated the perception of pain lower when the laser technique was used.
CONCLUSION:
In the small number of children studied, the application of the Er,Cr:YSGG laser system was a more comfortable alternative or adjunctive method to conventional mechanical cavity preparation. A far larger study is necessary to confirm this finding.
Bonding DOI   Ergücü, Z., Celik, E.U., Unlü, N., Türkün, M. and Ozer, F. Effect of Er,Cr:YSGG laser on the microtensile bond strength of two different adhesives to the sound and caries-affected dentin. Operative dentistry
Vol. 34(4), pp. 460-466 
2009 rank3
Abstract: OBJECTIVE: This study examined the effect of Er,Cr:YSGG laser irradiation on the microtensile bond strength (microTBS) of a three-step etch-and-rinse and a two-step self-etch adhesive to sound and caries-affected dentin. METHODS: Sixteen freshly extracted human molars with occlusal dentin caries were used. The caries lesion was removed by one of the following methods: conventional treatment with burs or Er,Cr:YSGG laser (Waterlase MD, Biolase). The adhesive systems (AdheSE, Ivoclar Vivadent and Scotchbond Multi Purpose, 3M ESPE) were applied to the entire tooth surface according to the manufacturers' instructions. Resin composites were applied to the adhesive-treated dentin surfaces and light-cured. Each tooth was sectioned into multiple beams with the "non-trimming" version of the microtensile test. The specimens were subjected to microtensile forces (BISCO Microtensile Tester, BISCO). The data was analyzed by three-way ANOVA and independent t-tests (p=0.05). RESULTS: Er,Cr:YSGG laser irradiation exhibited similar microTBS values compared to that of conventional bur treatment, regardless of the adhesive system and type of treated dentin. The self-etch system revealed lower microTBS values, both with conventional and laser treatment techniques, compared to the etch-and-rinse adhesive in sound and caries-affected dentin (p<0.05). CONCLUSION: Er,Cr:YSGG laser irradiation did not negatively affect the bonding performance of adhesive systems to sound and caries-affected dentin.
Bonding URL  Esteves-Oliveira, M., Zezell, D.M., Apel, C., Turbino, M.L., Aranha, A., Eduardo, C. and Gutknecht, N. Bond strength of self-etching primer to burr cut, Er,Cr:YSGG, and Er:YAG lased dental surfaces Photomedicine and laser surgery
Vol. 25(5), pp. 373-380 
2007 rank1
Abstract: OBJECTIVE:
The purpose of this study was to evaluate the tensile bond strength of a self-etching primer system to enamel and dentin surfaces treated with Er:YAG and Er,Cr:YSGG lasers.
BACKGROUND DATA:
The recently introduced self-etching primer systems have been shown to adhere better to dental surfaces with thin or no smear layers. Moreover, there have been no previous reports on the bond strength of these adhesives to Er,Cr:YSGG laser-irradiated enamel and dentin, which have been shown to be free of a smear layer.
METHODS:
Thirty samples of enamel and thirty of dentin were divided into three groups. The first group of each substrate served as a control with a standardized bur cut, and the other two groups were conditioned with Er:YAG (350 mJ, 10 Hz, 20 J/cm(2) for enamel; 300 mJ, 6 Hz, 17 J/cm(2) for dentin) and Er,Cr:YSGG laser (125 mJ, 20 Hz, 16 J/cm(2) for both substrates). After the bonding procedure, samples were restored with composite resin, and the tensile bond strength test was performed.
RESULTS:
The ANOVA two-way analysis and the Tukey test at 5% significance level showed that for enamel and dentin, the bond strength values were statistically higher in Er:YAG-laser treated than in Er,Cr:YSGG-laser treated surfaces (p = 0.0001). However, bond strength means for both laser-irradiated groups were statistically lower than for the bur cut group (Er:YAG: p = 0.0281 and Er,Cr:YSGG: p < 0.0001). SEM observation of laser-irradiated surfaces revealed a roughened aspect and absence of smear layer.
CONCLUSIONS:
The self-etching system adhesion was influenced by the type of erbium laser used, and the bond strength was higher in the Er:YAG-laser irradiated than in the Er,Cr:YSGG-laser irradiated surfaces.
Pain URL  Eversole, L.R., Rizoiu, I. and Kimmel, A. Pulpal response to cavity preparation by an Er,Cr:YSGG laser powered hydrokinetic system JADA
Vol. 128, pp. 1099-1106 
1997 rank1
Abstract: The near red-pulsed erbium, chromium:yttrium-scandium-gallium-garnet laser hydrokinetic system, or Er,Cr:YSGG laser HKS, is effective in cutting dental hard tissues. In this longitudinal study, the authors studied the continuously erupting open-apex incisors of New Zealand albino rabbits and the constricted apex teeth of beagles to determine the effects of HKS-produced lesions at various energy levels and of preparations produced by a tapered fissure bur on dental pulp. No pulpal inflammatory responses could be identified either immediately or 30 days after surgery in HKS preparations that removed enamel and dentin without pulp exposure.
Bonding URL  Garbui, B., Azevedo, C., Zezell, D., Aranha, A. and Matos, A. Er,Cr:YSGG Laser dentine conditioning improves adhesion of a glass ionomer cement Photomedicine and Laser Surgery
Vol. 31(9), pp. 453-460 
2013 rank2
Abstract: OBJECTIVE:
The purpose of this study was to evaluate the bond strength (BS) of different surface treatments, including laser irradiation, between conventional glass ionomer cement (GIC) and dentine.
METHODS:
Eighty-five human third molars were divided into five groups with one of the following treatments: G1- control group, had no treatment; G2, G3, and G4 were treated with Er,Cr:YSGG laser irradiation at 0.5 W, 20 Hz, 25 mJ, 9 J/cm(2) (G2); 1.0 W, 20 Hz, 50 mJ, 18 J/cm(2)(G3); and 1.5 W, 20 Hz, 75 mJ, 27 J/cm(2) (G4); and G5 was treated with GIC liquid, which contains polyacrylic acid. Scanning electron microscopy (SEM) evaluation (n=2) and micro-shear bond strength test (n=15) using the GIC bonded to dentine were performed after 24 h of water immersion. The data were analyzed by one way analysis of variance (ANOVA), according to irradiation protocol (p<0.001).
RESULTS:
G2 specimens presented the highest BS results (in MPa) (10.50±0.84), followed by G1 (4.77±0.59) and G5 (4.26±1.02), which were statistically similar. G3 (3.32±0.39) and G4 (2.94±0.50) demonstrated the lowest BS values, and the difference between these groups was not statistically significant (p>0.001). SEM analysis of G1 revealed that the smear layer covered the entire dentine surface, whereas in G2, G3, and G4, irregular dentine was detected with open dentinal tubules and protruded peritubular dentine. Laser pulses could easily be distinguished in G2 but not in G3 and G4. G5 revealed a thin smear layer with dentinal tubule apertures clearly detectable.
CONCLUSIONS:
Dentine treatment with an Er,Cr:YSGG laser irradiation at a power of 0.5 W increased the BS of conventional GIC.
Deciduous URL  Genovese, M. and Olivi, G. Laser in paediatric dentistry: patient acceptance of hard and soft tissue therapy European journal of paediatric dentistry
Vol. 9(1) 
2008 rank2
Abstract: Aim This study aimed to evaluate the laser therapy efficacy in paediatric dentistry, considering the subjective tolerance and acceptance of therapy in children needing both dental and soft tissue treatments. Methods A group of 50 patients from 6 to 12 years of age, needing both hard and soft tissue therapy was selected and treated, without anesthesia, with an Er,Cr:YSGG laser 2780 nm and an Er:YAG laser 2940 nm for a total of 100 treatments performed; before and after the treatment the patients experience was tested with Wong-Baker modified facial image scale. Results The study showed a good percentage of acceptance and tolerance of both laser treatments: a success rate of 90% for hard tissues and 63% for soft tissues was obtained; for the total 100 treatments the acceptance was of 75%. Conclusion The Erbium lasers are very effective in paediatric dentistry and are good treatment options
Microstructure / Mineral Content URL  Geraldo-Martins, V., Lepri, C.P. and Palma-Dibb, R. Influence of Er,Cr:YSGG laser irradiation on enamel caries prevention Lasers in Medical Science
Vol. 28, pp. 33-39 
2013 rank2
Abstract: The objective of this study was to evaluate the effects of chromium:yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser irradiation on the acid resistance of dental enamel. Forty human enamel samples were divided into four groups. They were manually irradiated with an Er,Cr:YSGG laser device (λ = 2.78 µm, 20 Hz, 20 s), in a scanning mode, with and without water cooling, according to the following parameters: Group 1: 0.25 W, 62.5 J/cm(2), no water cooling; group 2: 0.25 W, 62.5 J/cm(2), 5.0 ml/min; group 3: 0.5 W, 125 J/cm(2), no water cooling; group 4: 0.5 W, 125 J/cm(2), 5.0 ml/min. No airflow was used. Afterwards, the samples were submitted to an acid challenge and assessed by cross-sectional Knoop microhardness at different depths (20, 40, 60, 80, and 100 µm) from the outer enamel surface. Average values were obtained for both irradiated and control areas in each sample and they were compared to obtain a percentage of microhardness increase. Data were analyzed by analysis of variance and Fisher's exact test (α = 5%). The percentage of microhardness increase observed in group 1 (+23.58%) was similar to group 3 (+19.12%), but higher than groups 2 (+3.61%) and 4 (10.9%) (p < 0.05). The comparison of the depths showed that the Er,Cr:YSGG laser acted in the superficial layers of the dental enamel. The findings of the present study suggest that the energy densities of 62.5 and 125 J/cm(2) were capable of increasing the acid resistance of human enamel. The presence of water during irradiation makes it difficult to obtain an enamel surface more resistant to acids.
Bonding URL  Gorucu, J., Gurgan, S., Cakir, F.Y., Bicer, C.O. and Gorucu, H. The effect of different preparation and etching procedures on the microleakage of direct composite veneer restorations Photomedicina and Laser Surgery
Vol. 29(3), pp. 205-211 
2011 rank2
Abstract: OBJECTIVES:
The aim of this in vitro study was to compare the microleakage of direct composite veneer restorations prepared by a conventional dental bur or Er,Cr:YSGG (erbium, chromium doped yttrium scandium gallium garnet) laser and etched with different procedures.
METHODS:
Fifty maxillary incisor teeth prepared for direct veneers with gingival margins in dentin and incisal margins in enamel were randomly divided into five groups (n = 10): group 1 (control), prepared with diamond bur and etched with phosphoric acid; group 2, prepared with diamond bur and etched with Er,Cr:YSGG laser (Waterlase MD/Biolase); group 3, prepared with laser and not etched; group 4, prepared with laser and etched with phosphoric acid; and group 5, prepared and etched with laser. After the application of the etch and rinse adhesive system (Prime & Bond NT/Dentsply), teeth were restored with the nano ceramic restorative material (Ceram X Duo/Dentsply), subjected to thermocycling and immersed in 0.5% basic fuchsin dye for 24 h. The teeth were sectioned longitudinally and dye penetration was evaluated by a binocular stereomicroscope equipped with a measuring device. Data were analyzed by Kruskal-Wallis and Wilcoxon signed ranks tests. The level of significance was set at p = 0.05.
RESULTS:
Significant differences were observed in enamel of the five groups (p < 0.05). Minimal microleakage was observed in groups 1 and 3. The highest microleakage was evaluated in group 5 (p < 0.05). No significant differences were found among the five groups in dentin (p > 0.05). No differences were recorded between the microleakage values in enamel and dentin within each group and this was valid for all groups (p > 0.05).
CONCLUSIONS:
The results confirmed that enamel and dentin surfaces prepared with Er,Cr:YSGG laser for direct composite veneer restorations may provide comparable sealing.
Bonding URL  Gutknecht, N., Apel, C., Schafer, C. and Lampert, F. Microleakage of composite fillings in Er,Cr:YSGG laser-prepared class II cavities Lasers in Surgery and Medicine
Vol. 28(4), pp. 371-374 
2001 rank5
Abstract: Objective: If there is insufficient bonding to the enamel, the shrinkage of composites that occurs during polymerization can result in a gap between the filling material and the cavity wall. This gap permits the passage of bacteria or their metabolic products and also of various molecules and ions. This leads to hyper- sensitivity or secondary caries and is thus one of the causes of the failures encountered in composite restora- tions. The aim of this study was to examine the quality of the margins of composite fillings in Er,Cr:YSGG laser- prepared cavities by means of dye penetration. The results were compared with those of restoration in conventionally prepared and conditioned cavities.Study Design/Materials and Methods: To this end, 45 class II cavities in extracted molars were prepared. The teeth were divided into three groups. The first group served as a control group. The cavities were prepared in the classical manner by using a diamond, beveled and subsequently conditioned by the etching method. In group 2, the cavities were prepared and conditioned exclusively with the Er,Cr:YSGG laser. In group 3, laser preparation was supplemented by conditioning of the cavity with phosphoric acid. Results: No significant difference could be found between the classical preparation technique in combination with etching and the laser preparation method with supple- mentary etching (group 3). The degree of dye penetration was highest in the group undergoing laser-prepared restoration without additional etching (group 2) (Wilcoxon test, P<0.017). Conclusion: Although it was found in previous studies that there is no significant difference between bond strength of acid etched enamel and Er,Cr:YSGG laser etched enamel, the dye penetration rate differs. On the basis of the results of our study, the additional use of etching after Er,Cr:YSGG laser preparation is recom- mended as it is used in the classical cavity preparation technique
Bonding DOI URL  Hamamci, N., Akkurt, A. and Başaran, G. In vitro evaluation of microleakage under orthodontic brackets using two different laser etching, self etching and acid etching methods Lasers in Medical Science
Vol. 25(6), pp. 811-816 
2010 rank2
Abstract: This study evaluated the microleakage of brackets bonded by four different enamel etching techniques. Forty freshly extracted human premolars were divided randomly into four equal groups and received the following treatment: group 1, acid etching; group 2, self-etching primer (SEP); group 3, erbium:yttrium–aluminum–garnet (Er:YAG) laser etching; and group 4, erbium, chromium:yttrium–scandium–gallium–garnet (Er,Cr:YSGG) laser etching. After photopolymerization, the teeth were kept in distilled water for 1 month and then subjected to 500 thermal cycles. Then, the specimens were sealed with nail varnish, stained with 0.5% basic fuchsin for 24 h, sectioned, and examined under a stereomicroscope. In addition, they were scored for marginal microleakage at the adhesive–enamel and bracket–adhesive interfaces from the incisal and gingival margins. Statistical analyses consisted of the Kruskal–Wallis test and the Mann–Whitney U test with Bonferroni correction. Microleakage occurred between the adhesive–enamel and bracket–adhesive interfaces in all groups. For the adhesive–enamel surface, a significant difference was observed between group 1 and groups 2 (P = 0.011), 3 (P = 0.002), and 4 (P = 0.000) on the gingival side. Overall, significant differences were observed between group 1 and groups 3 (P = 0.003) and 4 (P = 0.000). In dental bonding procedures, acid etching was found to result in the least microleakage. Since etching with a laser decreases the risk of caries and is time-saving, it may serve as an alternative to acid etching.
Cavity Prep URL  Harashima, T., Kinoshita, J.-I., Kimura, Y., Brugnera, A., Zanin, F., Pecora, J.D. and Matsumoto, K. Morphological comparative study on ablation of dental hard tissues at cavity preparation by Er:YAG and Er,Cr:YSGG lasers Photomedicine and Laser Surgery
Vol. 23(1), pp. 52-55 
2005 rank2
Abstract: Objective: The purpose of this study was to evaluate morphologically the dental hard tissue ablation at the class V cavity preparation by two types of laser devices: Er:YAG and Er,Cr:YSGG lasers in vitro. Background Data: There have been no reports on the comparative study of dental tissue ablation at cavity preparation by Er:YAG and Er,Cr:YSGG lasers. Methods: Twenty-two extracted human mature molar teeth were used in this study and divided into two groups of 11 teeth each. The teeth of the Er:YAG laser-irradiated group were irradiated at the parameters of 250 mJ/pulse and 15 Hz with water spray, and those of the Er,Cr:YSGG laserirradiated group were irradiated at the parameters of 5 Wand 20 Hz with water spray. After cavity preparation, the teeth were dehydrated, coated with platinum, and examined by scanning electron microscopy. Results: Both of the laser devices were capable of ablating dental hard tissues, but similar, irregular, and rugged surface aspects with different depths were observed. Open dentinal tubules at the cavities prepared by Er,Cr:YSGG laser were more clearly visible than those prepared by Er:YAG laser. Smaller width and stripped surfaces were observed on the cavities prepared by Er,Cr:YSGG laser. Conclusion: The results suggested that there is little difference between the two types of lasers—Er:YAG and Er,Cr:YSGG lasers—morphologically for class V cavity preparation, because both lasers were capable of preparing class V cavities, and the morphological features of the irradiated surfaces were very similar.
Restorative DOI   Hatipoglu, M. and Barutcigil Effects of erbium- and chromium-doped yttrium scandium gallium garnet and diode lasers on the surfaces of restorative dental materials: A Scanning electron microscope study Nigerian Journal of Clinical Practice
Vol. 18(2), pp. 213-220 
2015 rank1
Abstract: AIM: The aim of this study is to evaluate the potential effects of laser irradiation, which is commonly performed in periodontal surgery, on the surfaces of restorative materials. MATERIALS AND METHODS: Five different restorative dental materials were used in this study, as follows: (1) Resin composite, (2) poly acid-modified resin composite (compomer), (3) conventional glass ionomer cement (GIC), (4) resin-modified glass ionomer cement (RMGIC), and (5) amalgam. Four cylindrical samples (8 mm diameter, 2 mm height) were prepared for each restorative material. In addition, four freshly extracted, sound human incisors teeth were selected. Two different laser systems commonly used in periodontal surgery were examined in this study: A 810 nm diode laser at a setting of 1 W with continuous-phase laser irradiation for 10 s, and an erbium-and chromium-doped yttrium scandium gallium garnet (Er,Cr:YSGG) laser at settings of 2.5 W, 3.25 W, and 4 W with 25 Hz laser irradiation for 10 s. Scanning electron microscopy (SEM) analysis was performed to evaluate the morphology and surface deformation of the restorative materials and tooth surfaces. RESULTS: According to the SEM images, the Er,Cr:YSGG laser causes irradiation markings that appear as demineralized surfaces on tooth samples. The Er,Cr:YSGG laser also caused deep defects on composite, compomer, and RMGIC surfaces because of its high power, and the ablation was deeper for these samples. High-magnification SEM images of GIC samples showed the melting and combustion effects of the Er,Cr:YSGG laser, which increased as the laser power was increased. In amalgam samples, neither laser left significant harmful effects at the lowest power setting. The diode laser did cause irradiation markings, but they were insignificant compared with those left by the Er,Cr:YSGG laser on the surfaces of the different materials and teeth. CONCLUSION: Within the limitations of this study, it can be concluded that Er,Cr:YSGG laser irradiation could cause distortions of the surfaces of restorative materials. Diode lasers can be preferred for periodontal surgery.
Microstructure / Mineral Content URL  Hossain, M., Kimura, Y., Nakamura, Y., Yamada, Y., Kinoshita, J.-I. and Matsumoto, K. A study on acquired acid resistance of enamel and dentin irradiated by Er,Cr:YSGG laser Journal of Clinical Laser Medicine & Surgery
Vol. 19(3), pp. 159-163 
2004 rank3
Abstract: Objective: This investigation was performed to evaluate the acid resistance of lased enamel and dentin by Er,Cr:YSGG laser to artificial caries-like lesions by spectrophotometry, and the ultrastructure of lased areas was investigated by scanning electron microscopy (SEM) in vitro. Background Data: In recent years, many studies have been performed to evaluate the effects of Er,Cr:YSGG laser on dental hard tissues. However, there have been only a few studies to determine if this laser is suitable for caries preventive treatments. Methods: An Er,Cr:YSGG laser was used to irradiate the enamel or dentin samples from 30 extracted human molars at 6 W (67.9 J/cm2) or 5 W (56.6 J/cm2) pulse energy, respectively, with or without water mist. Samples were subjected to 2 μl of 0.1 M lactic acid solution (pH 4.8) for 24 h at 36°C. The parts per million (ppm) of calcium ion (Ca2+) dissolved in each solution was determined by atomic absorption spectrophotometery, and the morphological changes were investigated by SEM. Results: The lowest mean Ca2+ ppm was recorded in the lased samples. SEM observation showed that the lased areas were melted and seemed to be thermally degenerated. After acid demineralization, the thermally degenerated enamel or dentin surfaces were almost unchanged. Conclusions: The results of this study suggested that Er,Cr:YSGG laser irradiation with and without water mist appears to be effective for increasing acid resistance
Cavity Prep URL  Hossain, M., Nakamura, Y., Yamada, Y., Suzuki, N., Murakami, Y. and Matsumoto, K. Analysis of Surface Roughness of Enamel and Dentin after Er,Cr:YSGG Laser Irradiation Journal of Clinical Laser Medicine & Surgery
Vol. 19(6), pp. 297-303 
2001 rank4
Abstract: Objective: The purpose of this investigation was to compare the surface roughness of enamel and dentin fol- lowing the Er,Cr:YSGG laser irradiation and acid etching. Background Data: Laser-roughened enamel or dentin surfaces have been expected to enhance restorative materials bond strength. Materials and Methods: Er,Cr:YSGG laser irradiation was performed in one half of each polished enamel or dentin sample at 3 W (33.9 J/cm2, with air 70% and water 20%,) pulse energy for 6 sec. Then the other half was treated with 37% phosphoric acid for 30 sec. Surface roughness and morphological studies were performed. Results: It was found that surface roughness was significantly increased with the laser system. Scanning electron microscopy analysis showed that irradiated surface produces a rough surface that was completely lacking of a smear layer; there was also no cracking of enamel or dentin. Conclusion: Er,Cr:YSGG laser irradiation could provide an ef- fective and alternative method to the acid etch technique. INTRODUCTION
Cavity Prep URL  Hossain, M., Yukio Nakamura, Y.Y., Kimura, Y., Matsumoto, N. and Matsumoto, K. Effects of Er,Cr:YSGG laser irradiation in human enamel and dentin: ablation and morphological studies Journal of Clinical Laser Medicine & Surgery
Vol. 17(4), pp. 155-159 
2009 rank1
Abstract: Objective: This investigation was performed to determine quantitatively the ranges of ablation and to evaluate the morphological changes in human enamel and dentin irradiated by Er,Cr:YSGG laser with or without water spray. Summary Background Data: Recently, Er,Cr:YSGG laser has been introduced in dental clinics to remove carious dental hard tissues in anticipation of replacing the high-speed dental drill. Methods: A total of 40 extracted human teeth were used in this study. An Er,Cr:YSGG laser was used to ablate human dental hard tissues with the output powers of 3 to 6 W. Ablation extent with or without water spray at different output powers was measured, and the morphological changes on enamel and dentin were also investigated by stereoscopy and scanning electron microscopy (SEM). Results: The irradiation with water spray significantly (p < 0.001) increased the ablation depths compared to those irradiated without water mist. Morphological findings by SEM indicated that when irradiated without water spray, carbonization with brown or dark color was recognized in enamel or dentin, respectively. In addition, cavities with a molten lava-like appearance were produced and an irregular structure with many microholes was observed in dentin. Conclusions: These results suggest that during the Er,Cr:YSGG laser irradiation, water spray directed at the ablation sites increases the ablation depths and water plays an important role as an initiator of the ablation of dental hard tissues
Restorative URL  Iaria, G. Clinical, morphological, and ultrastructural aspects with the use of Er:YAG and Er,Cr:YSGG lasers in restorative dentistry General Dentistry, pp. 636  2008 rank1
Abstract: The Er:YAG laser has an active medium of Yttrium-Aluminium-Garnet doped with Erbium ions and emits free-running pulsed laser energy at a wavelength of 2940 nm. The Er,Cr:YSGG laser has an active medium of Yttrium-Scandium-Gallium-Garnet doped with Erbium and Chromium ions and emits free-running pulsed laser energy at a wavelength of 2780 nm. These wavelengths have a high absorption in water, which makes their application appropriate for ablating oral soft tissue as well as dental hard tissue. This article examines the principles of use for the Er:YAG and Er,Cr:YSGG lasers in clinical restorative dentistry and reviews the literature regarding different aspects of the use of laser energy on hard tissues.
Deciduous URL  Jacobson, B., Berger, J., Kravitz, R. and Ko, J. Laser pediatric Class II composites utilizing no anesthesia Journal of Clinical Pediatric Dentistry
Vol. 28(2), pp. 99-101 
2005 rank3
Abstract: Interproximal lesions can now be restored without local anesthesia and removing unnecessary healthy tooth structure. This paper will focus on a new ultra-conservative technique in Class II composites utilizing the laser, a new technique in cavity preparation
Restorative DOI URL  Jorge, A.C.T., Cassoni, A., Freitas, P.M.D., Reis, A.F., Brugnera Junior, A. and Rodrigues, J.A. Influence of Cavity Preparation with Er,Cr:YSGG Laser and Restorative Materials on In Situ Secondary Caries Development. Photomedicine and laser surgery
Vol. 33(2), pp. 98-103 
2015 rank5
Abstract: Objective: The aim of this study was to evaluate the influence of cavity preparation and restorative materials containing fluorides in the prevention of secondary caries lesion development in situ. Methods: A total of 120 blocks obtained from human teeth were divided into two groups and standardized cavities were prepared using diamond burs (DB) or Er,Cr:YSGG-laser [20 Hz, 4.0W, 55% water, 65% air (LA)]. They were divided into three subgroups according to the restorative material (n=20): glass-ionomer cement (GI), resin modified glass-ionomer (RM) or composite resin (CR). Blocks were fixed in palatal intra-oral appliances worn in situ by 20 human volunteers, who dropped 20% sucrose solution eight times daily. After 21 days, blocks were removed and restorations were cross-sectioned to evaluate microhardness [Knoop hardness number (KHN)] underneath enamel surface from 30 to 200 μm. Factors "cavity preparation," "restorative materials," and "depth" were evaluated by three way ANOVA, followed by Tukey test (p<0.05). Results: The results showed lower microhardness in cavities prepared with DB than in cavities prepared with LA. At 30 μm, there were no statistical significant differences with regard to "cavity preparation" or "restorative materials" factors. In depth evaluation, the enamel microhardness progressively increased as a function of depth for the GI groups. In the groups prepared with LA at 60 μm/90 μm, there were no significant differences between GI and RM materials, whose microhardnesses were significantly higher than that of CR. Conclusions: Cavity preparation using Er,Cr:YSGG laser increases caries resistance of enamel walls, and reduce caries lesion depth development regardless of fluoride presence in the restorative material. CR showed higher caries lesion development than GI, and RM showed intermediate results.
Cavity Prep DOI   Kang, H., Rizaoiu, I. and Welch, A. Effect of Water Spray during Laser Ablation on Dental Hard Tissue Proc. of SPIE
Vol. 6425 
2007 rank3
Abstract: In this study, we investigated the role of water spray. To ablate human enamel tissue, a long-pulsed Er,Cr:YSGG laser was used at various radiant exposures. During dental ablation, distilled water was sprayed to the sample surface. Desiccated samples were also tested with direct irradiation for comparison. In order to identify dominant ablation mechanisms, transient acoustic waves were measured using a piezoelectric microphone. Enamel ablation efficiency was evaluated with Optical Coherence Tomography (OCT). Material removal was up to four times larger at the best flow rate with respect to ablation without spray. In spite of 60 % higher damage threshold by water absorption, spray ablation enhanced both the laser-induced acoustic transients up to six times and the ablation efficiency up to twice over the entire range of radiant exposures tested, compared to dry ablation. The improved pressure and ablation performance of the spray-assisted process with cooling effect were thought to be induced by recoil stress, rapid water vaporization, interstitial water explosion, and/or liquid-jet formation. Spray ablation along with water cooling and abrasive mechanical effects can be a safe and efficient modality for dental treatment.
Cavity Prep DOI   Kang, H.W., Rizoiu, I. and Welch, A. Hard tissue ablation with a spray-assisted mid-IR laser Physics in Medicine and Biology
Vol. 52, pp. 7243-7259 
2007 rank3
Abstract: The objective of this study was to understand the dominant mechanism(s) for dental enamel ablation with the application of water spray. A free-running Er,Cr:YSGG (yttrium, scandium, gallium, garnet) laser was used to ablate human enamel tissue at various radiant exposures. During dental ablation, distilled water was sprayed on the sample surface, and these results were compared to ablation without a spray (dry ablation). In order to identify dominant ablation mechanisms, transient acoustic waves were compared to ablation thresholds and the volume of material removed. The ablation profile and depthweremeasured using optical coherence tomography (OCT). Irregular surface modification, charring and peripheral cracks were associated with dry ablation, whereas craters for spray samples were relatively clean without thermal damage. In spite of a60%higher ablation threshold for spray associated irradiations owing to water absorption, acoustic peak pressures were six times higher and ablation volume was up to a factor of 2 larger compared to dry ablation. The enhanced pressure and ablation performance of the spray-assisted process was the result of rapid water vaporization, material ejection with recoil stress, interstitialwater explosion and possibly liquid-jet formation. Withwater cooling and abrasive/disruptive mechanical effects, the spray ablation can be a safe and efficient modality for dental treatment.
Bonding DOI   Karaman, E., Yazici, A.R., Baseren, M. and Gorucu, J. Comparison of acid versus laser etching on the clinical performance of a fissure sealant: 24-month results. Operative Dentistry
Vol. 38(2), pp. 151-158 
2013 rank3
Abstract: OBJECTIVE: To compare the clinical performance of a pit and fissure sealant placed with the use of different enamel preparation methods, i.e. acid or Er,Cr:YSGG laser etching, over 24 months.METHODS: Sixteen subjects (15 female, 1 male) with no restorations or sealant present on their fissures and no detectable caries participated. Using a table of random numbers, a total of 112 sealants (56 with acid-etching, 56 with laser etching) were placed on the permanent premolar and molar teeth. All restorative procedures except for application of the laser were performed by the same dentist. After completion of the fissure preparation either with acid or laser, the adhesive was applied; then a pit and fissure sealant, Clinpro Sealant, was placed and polymerized. Clinical evaluations were done at baseline and at 6-, 12-, 18-, and 24-month follow-up visits by two calibrated examiners, who were unaware of which etching method had been used. The retention of sealants and caries were evaluated with the aid of a dental explorer and an intra-oral mirror. Each sealant was evaluated using the following criteria: 1=completely retained; 2= partial loss; 3= total loss. The Pearson chi-square test was used to evaluate differences in the retention rates among the sealants used with different etching methods.RESULTS: All patients attended the 24-month follow-up visit and all sealants were evaluated (total recall rate 100%). At the end of 24 months, 83.9% of the sealants from laser group and 85.7% of those from acid-etch group were recorded as "completely retained". There were no statistically significant differences in retention rates among the preparation methods after all evaluation periods (p>0.05). No statistically significant differences were found between the retention rates of premolar and molars at each evaluation period. No secondary caries was detected in association with any sealants.CONCLUSION: The clinical performance of fissure sealants placed after acid or Er,Cr:YSGG laser etching was similar
Bonding DOI URL  Kato, C., Taira, Y., Suzuki, M., Shinkai, K. and Katoh, Y. Conditioning effects of cavities prepared with an Er,Cr:YSGG laser and an air-turbine Odontology
Vol. 100(2), pp. 164-171 
2012 rank3
Abstract: The purpose of this study was to examine, morphologically and histochemically, five types of conditioning effects on cavities prepared with an Er,Cr:YSGG laser and an air-turbine. Cavities were prepared using a Waterlase® MD turbo handpiece (W) and an air-turbine (AT) on human extracted molars. The cavity conditionings used were non-conditioned (G1), K-etchant Gel (G2), K-etchant Gel + AD Gel (G3), Clearfil SE Bond primer (G4) and Clearfil S3 Bond (G5). On naked eye observations, enamel of G1, G2 and G3 in the W cavities and etched enamel of G2 and G3 in the AT cavities were observed as rough and dull in appearance. G4 and G5 in W and AT cavities were observed as shiny surfaces. On SEM observations, no smeared layer was observed in W cavities, while a smeared layer and bur-scratches were observed in AT cavities. In W cavities, rough surfaces were observed on enamel. That is, cracks and minute rough surfaces were observed. In contrast, equally etched scale-shaped enamel rods were observed in AT cavities. Widely opened dentinal tubules and protruding peritubular matrices of dentin were observed in W cavities. A few remaining smeared plugs could be observed at the AT cavities. On LM observations, 13–16 μm layers of the dentin in G1, G2, G4 and G5 of W cavities were stained red in color by the Azan staining method, while redness was not observed in G3. No groups were stained red in AT cavities. It was considered that layers stained red in color were thermal degeneration layers of dentin induced by W. Namely 30 s etching of 40% phosphoric acid gel followed by 90 s treatment of 10% NaClO gel should be recommended for use when combined with an Er,Cr:YSGG laser for cavity preparation.
Thermal Effects URL  Kilinc, E., Roshkind, D.M., Antonson, S.A., Antonson, D.E., Hardigan, P.C., Siegel, S.C. and Thomas, J.W. Thermal Safety of Er:YAG and Er,Cr:YSGG Lasers in Hard Tissue Removal Photomedicine and Laser Surgery
Vol. 27(4), pp. 565-570 
2009 rank3
Abstract: Objective: The aim of this study was to compare the thermal safety of Er:YAG and Er,Cr:YSGG lasers with conventional multi-use and single-use diamond burs. Background Data: Thermal effect of tooth preparation is mostly evaluated through the pulp chamber because it is difficult to measure the temperature of the preparation surface. A new in vitro method was introduced to simultaneously evaluate the heat increase of the preparation surface together with the pulp chamber. Methods: Six laser and bur instrument groups were used to make standardized preparations on buccal surfaces of 60 intact third molars. The preparations removed an equal volume of hard tissue from each tooth (4 mm occluso-gingival × 8 mm mesial-distal × 1.6 mm bucco-lingual). The teeth also included tunnel preparations from the opposite (lingual) surface, exposing the pulpal axial wall (axial dentin wall in contact with the pulp chamber from the preparation surface site). An infrared thermal camera was positioned to capture the preparation surface in direct vision, while the pulpal axial wall was indirectly reflected to the thermal camera via a minimal-energy-loss mirror. Data from both surfaces were analyzed statistically using Nested Least Squares Analysis. Results: The laser groups generated significantly lower heat compared to bur groups on the preparation surfaces. In contrast, both lasers generated greater pulpal heat increase, and the Er:YAG laser group showed significance (p < 0.0001). Conclusions: Lasers produced less heat on the preparation surface but more on the pulpal axial wall. However the temperature rise was less than the 5.5°C threshold margin of safety.
Cavity Prep URL  Kinoshita, J.-I., Kimura, Y. and Matsumoto, K. Comparative Study of Carious Dentin Removal by Er,Cr:YSGG Laser and Carisolv Journal of Clinical Laser Medicine & Surgery
Vol. 21(5), pp. 307-315 
2003 rank5
Abstract: Objective: The present study aimed to compare carious dentin removal by air turbine, Carisolv and erbium,chromium:yttrium,scandium,gallium,garnet (Er,Cr:YSGG) laser, and examine morphological changes before and after these caries removal techniques under light microscopy and scanning electron mi- croscopy (SEM). Background Data: Although there have been numerous studies on removing caries by Er,Cr:YSGG laser, none has compared Er,Cr:YSGG laser and Carisolv, or reported on the usage of DIAGN- Odent as a diagnostic tool particularly for advanced caries in in vitro experiments. Materials and Methods: Sixty extracted human teeth diagnosed as advanced caries were divided into three groups based on the treat- ment received, namely air turbine, Carisolv, and Er,Cr:YSGG laser groups. Each group was sub-divided into two in order to examine the results with or without finishing using nylon brush, 15% ethylene diamine tetraacetic acid (EDTA) or low-power laser, respectively. After evaluation by DIAGNOdent, specimens were observed under light microscopy or SEM. Results: Light microscopic observations varied considerably in the three treatment groups. SEM revealed that the surfaces treated by air turbine were very smooth, but with substantial debris. The Carisolv group exhibited a very rough surface with a thick smear layer, while the Er,Cr:YSGG group demonstrated smooth undulations with little smear layer and debris. Among the finishing techniques, the laser group demonstrated the best efficiency. DIAGNOdent scores supported the results of light microscopy. Conclusion:These results suggest that caries removal by Er,Cr:YSGG laser is very effective even without finishing and DIAGNOdent is useful for diagnosing advanced caries in in vitro experiments. INTRODUCTION
Cavity Prep URL  Kuščer, L. and Diaci, J. Measurements of erbium laser-ablation efficiency in hard dental tissues under different water cooling conditions Journal of Biomedical Optics
Vol. 18(10) 
2013 rank5
Abstract: Laser triangulation measurements of Er:YAG and Er,Cr:YSGG laser-ablated volumes in hard dental tissues are made, in order to verify the possible existence of a “hydrokinetic” effect that has been proposed as an alternative to the “subsurface water expansion” mechanism for hard-tissue laser ablation. No evidence of the hydrokinetic effect could be observed under a broad range of tested laser parameters and water cooling conditions. On the contrary, the application of water spray during laser exposure of hard dental material is observed to diminish the laser-ablation efficiency (AE) in comparison with laser exposure under the absence of water spray. Our findings are in agreement with the generally accepted principle of action for erbium laser ablation, which is based on fast subsurface expansion of laser-heated water trapped within the interstitial structure of hard dental tissues. Our measurements also show that the well-known phenomenon of ablation stalling, during a series of consecutive laser pulses, can primarily be attributed to the blocking of laser light by the loosely bound and recondensed desiccated minerals that collect on the tooth surface during and following laser ablation. In addition to the prevention of tooth bulk temperature buildup, a positive function of the water spray that is typically used with erbium dental lasers is to rehydrate these minerals, and thus sustaining the subsurface expansion ablation process. A negative side effect of using a continuous water spray is that the AE gets reduced due to the laser light being partially absorbed in the water-spray particles above the tooth and in the collected water pool on the tooth surface. Finally, no evidence of the influence of the water absorption shift on the hypothesized increase in the AE of the Er,Cr:YSGG wavelength is observed.
Microstructure / Mineral Content URL  Lin, S., Pan, D., Lin, Q., Yin, S., Chen, D., Liu, Q., Yu, L. and Lin, Z. Evaluation of phase, microstructure and composition of human dentine after Er,Cr:YSGG laser irradiation Journal of Nanoscience and Nanotechnology
Vol. 11(3), pp. 2421-2426 
2011 rank5
Abstract: This study aims to evaluate the composition, micro-structure and inorganic phase alternations of human dentine irradiated by Er, Cr:YSGG laser with water cooling spray system. X-ray diffraction (XRD) analysis indicated that the main inorganic phase of dentine before and after laser irradiation were all Hydroxyapatite (HA) structure, approximately 30 nm in size. No significant changes occurred in the average particle size after irradiation in four energy densities (6.18 J/cm2, 8.04 J/cm2, 9.89 J/cm2, 11.1 J/cm2). Atomic force microscope (AFM) phase image and the energy-dispersive spectroscope (EDS) analysis, however, demonstrated that the thermal effects of Er, Cr:YSGG laser with water-cooling spray system on the dentin surface was intense enough to induce notable decrease of the organic matter. Both scanning electron microscopy (SEM) and AFM analysis showed that the irradiated dentine presented rough surface morphology. The surface is clean and dentinal tubules are completely open. The ablation rate of both peri- and intertubular dentine increased at higher energy densities but no significant changes of gross appearance took place. Chemical analysis reveals that laser photothermal effect would decrease significantly the organic content of superficial dentinal layer. We conclude that the Er, Cr:YSGG laser, as a new type clinic laser, would not significantly influence the inorganic phase structure of the surface dentine layer, however, thermal ablation was occurred in organic component. Moreover, the rough ablated surface as well as the opened dentinal tubules induced by irradiation, might be advantageous to the infiltration of the adhesive materials, thus the adhesion of dental restoration could be enhanced. Further studies should focus on the correlation between bond strength and Er, Cr:YSGG lased dentine.
Microstructure / Mineral Content DOI   Malkoc, M.A., Taşdemir, S.T., Ozturk, A.N., Ozturk, B. and Berk, G. Effects of laser and acid etching and air abrasion on mineral content of dentin Lasers in Medical Science
Vol. 26, pp. 21-27 
2011 rank5
Abstract: The aim of this study was to evaluate the mineral content of dentin prepared using an Er,Cr:YSGG laser at four different power settings, acid etching, and air abrasion. The study teeth comprised 35 molars which were randomly divided into seven equal groups. The occlusal third of the crowns were cut with a slow-speed diamond saw. The groups were as follows: group A, control group; group B, dentin etched with 35% buffered phosphoric acid for 30 s; group C, dentin abraded at 60 psi with 50-µm aluminium oxide for 1 s; groups D–G, dentin irradiated with the Er,Cr:YSGG laser at 1.50 W (group D), 2.25 W (group E), 3.00 W (group F), and 3.50 W (group G). The levels of Mg, P, Ca, K and Na in each dentin slab were measured by inductively coupled plasma-atomic emission spectrometry (ICP-AES). Data were analysed by one way analysis of variance and Tukey HSD tests. There were no significant differences between the groups in the levels of Ca, P and Na, and the Ca/P ratio (p>0.05); however, there were significant differences in the levels of K (p<0.001) and Mg (p=0.13). In addition, the levels of Mg in the air abrasion group were higher than in the other groups (p<0.01). Etching with the Er,Cr:YSGG laser system, air abrasion and acid etching did not affect the levels of Ca, P and Na, or the Ca/P ratio, in the dentin surface.
Bonding URL  Marotti, J., Geraldo-Martins, V.R., Bello-Silva, M.S., Eduardo, C.d.P., Apel, C. and Gutknecht, N. Influence of etching with Er,Cr:YSGG laser on microleakage of class V restoration Lasers in Medical Science
Vol. 25(3), pp. 325-329 
2010 rank3
Abstract: The aim of this in vitro study was to evaluate some parameters of dental etching when irradiated with an erbium, chromium:yttrium–scandium–gallium–garnet (Er,Cr:YSGG) laser. One-hundred sound human third molars were selected and randomly distributed into ten groups (n = 10). The class V cavities of group 1 (control) were prepared with a bur and etched with 37% phosphoric acid, while groups G2 to G10, were prepared with laser (5 W, 88.46 J/cm2, 90/70% air/water) and etched with the following powers: G3 and G4, 0.25 W; G5 and G6, 0.5 W; G7 and G8, 0.75 W; G9 and G10, 1 W. Group G2 received no laser etching. Prior to restoration, G2, G4, G6, G8 and G10 received acid etching. After restoration, all samples were submitted to a microleakage test. According to statistical analysis (Kruskal–Wallis and Dunn's tests), G10 presented the lowest microleakage values (P<0.05). The other groups showed no differences between them. Etching with Er,Cr:YSGG laser (1 W) followed by phosphoric acid was effective in reducing the microleakage of class V restorations.
Bonding URL  Moretto, S.G., Azambuja, N., Arana-Chavez, V.E., Reis, A.F., Giannini, M., Eduardo, C.d.P. and Freitas, P.M.D. Effects of ultramorphological changes on adhesion to lased dentin - scanning electron microscopy and transmission electron microscopy analysis Microscopy Research and Technique
Vol. 74(8), pp. 720-726 
2011 rank3
Abstract: Dentin irradiation with erbium lasers has been reported to alter the composite resin bond to this treated surface. There is still a lack of studies reporting the effect of erbium lasers on dentin organic content and elucidating how laser treatment could interfere in the quality of the resin-dentin interface. This study aimed to evaluate the effect of erbium laser irradiation on dentin morphology and microtensile bond strength (μTBS) of an adhesive to dentin. Seventy-two dentin disks were divided into nine groups (n = 8): G1-Control (600-grit SiC paper); Er:YAG groups: G2- 250 mJ/4 Hz; G3- 200 mJ/4 Hz; G4- 180 mJ/10 Hz; G5- 160 mJ/10 Hz; Er,Cr:YSGG groups: G6- 2 W/20 Hz; G7- 2.5 W/20 Hz; G8- 3 W/20 Hz; G9- 4 W/20 Hz. Specimens were processed for cross-sectional analysis by scanning electron microscopy (SEM) (n = 3), transmission electron microscopy (TEM) (n = 2), and adhesive interface (n = 3). Forty-five dentin samples (n = 5) were restored and submitted to μTBS testing. ANOVA (α = 5%) revealed that G1 presented the highest μTBS values and irradiated groups did not differ from each other. TEM micrographs showed a superficial layer of denatured collagen fibrils. For SEM micrographs, it was possible to verify the laser effects extending to dentin subsurface presenting a rough aspect. Cross-sectional dentin micrographs of this hybridized surface revealed a pattern of modified tags with ringlike structures around it. This in vitro study showed that erbium laser irradiation interacts with the dental hard tissue resulting in a specific morphological pattern of dentin and collagen fibrils that negatively affected the bond strength to composite resin.
Bonding DOI   Navimipour, E.J., Oskoee, S.S., Oskoee, P.A., Bahari, M., Rikhtegaran, S. and Ghojazadeh, M. Effect of acid and laser etching on shear bond strength of conventional and resin-modified glass-ionomer cements to composite resin Lasers in Medical Science
Vol. 27(2), pp. 305-311 
2012 rank5
Abstract: Success in sandwich technique procedures can be achieved through an acceptable bond between the materials. The aim of this study was to compare the effect of 35% phosphoric acid and Er,Cr:YSGG laser on shear bond strength of conventional glass-ionomer cement (GIC) and resin-modified glass-ionomer cement (RMGIC) to composite resin in sandwich technique. Sixty-six specimens were prepared from each type of glass-ionomer cements and divided into three treatment groups as follows: without pretreatment, acid etching by 35% phosphoric acid for 15 s, and 1-W Er,Cr:YSGG laser treatment for 15 s with a 600-μm-diameter tip aligned perpendicular to the target area at a distance of 1 mm from the surface. Energy density of laser irradiation was 17.7 J/cm(2). Two specimens in each group were prepared for evaluation under a scanning electron microscope (SEM) after surface treatment and the remainder underwent bonding procedure with a bonding agent and composite resin. Then the shear bond strength was measured at a crosshead speed of 0.5 mm/min. Two-factor analysis of variance and post-hoc Tukey test showed that the cement type, surface treatment method, and the interaction of these two factors significantly affect the shear bond strength between glass-ionomer cements and composite resin (p < 0.05). Surface treatment with phosphoric acid or Er,Cr:YSGG laser increased the shear bond strength of GIC to composite resin; however, in RMGIC only laser etching resulted in significantly higher bond strength. These findings were supported by SEM results. The fracture mode was evaluated under a stereomicroscope at ×20.
Bonding URL  Obeidi, A., McCracken, M.S., Liu, P.-R., Litaker, M.S., Beck, P. and Rahemtulla, F. Enhancement of bonding to enamel and dentin prepared by Er,Cr:YSGG laser Lasers in Surgery and Medicine
Vol. 41(6), pp. 454-462 
2009 rank5
Abstract: Background and Objective Erbium lasers are potential tools to remove caries and dental hard tissue but bond strengths of composites to those preparations are reported to be lower than conventional methods. The purpose of this study was to evaluate the effect of mechanical excavation and/or chemical alteration on bond strength of composites to laser irradiated enamel and dentin. Materials and Methods Seventy-two premolars were ground to obtain flat enamel (E, n = 36) or dentin (D, n = 36) surfaces in both buccal and lingual cusps, divided into: LaserExcavation (LEx), LaserNo-excavation (LNex), and Bur (B) groups. The laser groups were irradiated for 10 seconds by Er,Cr:YSGG laser [4.5 W, 60% air, 80% water (enamel) 3 W, 60% air, 70% water (dentin)]. Irradiated surfaces in the excavation groups (Ex) were then mechanically smoothed with a dental excavator, prepared surfaces were then etched (37% H3PO4) for 20 or 40 seconds (enamel) and 15 or 30 seconds (dentin), washed (20 seconds), adhesive was applied(Single Bond Plus), and light cured (20 seconds). A composite cylinder (Filtek Supreme Plus) formed, placed and light cured (40 seconds). The specimens were stored (37°C,48 hours), shear bond tested (1 mm/minute), and statistically analyzed (P < 0.05). Results Mixed-model ANOVA showed significant differences between enamel (P = 0.0091) and between dentin groups (P = 0.0035). Tukey/Kramer showed mean shear bond strength (SBS±SE) of EB40 (27.01±2.38 MPa) was significantly higher than ELNoExc20 (14.39±2.5 MPa) and ELExc40 (14.90±2.28 MPa). Also DB30 (17.57± 1.67 MPa) and DLExc30 (18.6±1.74 MPa) were significantly higher than DLNoExc15 (9.56±1.86 MPa). Conclusion Increasing the etching time up to 40 seconds or excavation of the laser prepared surface (but not the combination) may increase the bond strength to the level of conventional methods in enamel but excavation has a greater influence in dentin. Also the combination of both methods [excavation+longer etching time (30 seconds)] exhibit significantly better results in dentin. Mode of failure study showed mechanical excavation in both enamel and dentin can significantly reduce the cohesive failure in tooth structure.
Microstructure / Mineral Content DOI   Olivi, G. and Angiero, F. Use of the erbium , chromium : yttrium – scandium – gallium – garnet laser on human enamel tissues . Influence of the air – water spray on the laser – tissue interaction : scanning electron microscope evaluations Lasers in Medical Science  2008 rank4
Abstract: The study investigated the influence of varying amounts of air/water spray and the energy used by an erbium, chromium:yttrium–scandium–gallium–garnet (Er,Cr:YSGG) 2,780 nm laser when treating dental tissues. The morphological effects produced by the laser interaction on healthy human enamel were evaluated by scanning electron microscopy (SEM). The vestibular and lingual surfaces of ten molars were treated with laser at different power settings; each surface was subdivided into cervical, median, and occlusal parts and treated with different proportions of water spray; the series contained 60 tooth portions. Treatment differed in terms of power setting and air/water percentage. All specimens were then subjected to dehydration and metallisation. At SEM evaluation, the classic aspect of laser-treated enamel was visible: grooves, flakes, shelves and sharp edges, indicative of micro-explosion rather than melting. Vaporisation of the tissue created a clear delimitation from surrounding healthy tissue, with partial respect to the prismatic structure of the treated enamel. The aspect of the enamel was rarely type 1 Silverstone but more frequently type 2 or 3, with prismatic structure not respected and/or completely disordered. These morphological differences appeared to be correlated with the inclination of the laser beam aimed at the enamel prisms and with the percentage of air/water used. The laser system analysed showed itself to be effective at removing human dental enamel. The results appeared to be closely correlated with the variation of the percentage of the laser's water–air spray.
Frenectomy, Microstructure / Mineral Content URL  Olivi, G., Chaumanet, G., Genovese, M.D., Beneduce, C. and Andreana, S. Er,Cr:YSGG laser labial frenectomy: A clinical retrospective evaluation of 156 consecutive cases General Dentistry  2010 rank4
Abstract: The labial frenum may impede oral hygiene and result in diastema between anterior teeth and traction of the attached gingiva. Surgical removal of the frenum during puberty has been recommended for these patients. This article clinically evaluates the efficacy of an Er,Cr:YSGG laser in removing the labial frenum in an adolescent and pre-pubescent population. Using an Er,Cr:YSGG laser at a power setting of 1.5 W or less and 20–30 pulses per second, a total of 156 frenectomies were performed on 143 children. Patients returned for recall visits at 3, 7, 21, and 30 days and at one, two, and three years. Surgical areas were checked for adverse events, recurrency of frenum, and functional complications. Patient acceptance was also evaluated by using the Wong-Baker FACES pain rating scale. Thirteen recurrences were reported in the adolescent population at 21 or 30 days, all of which required re-intervention; however, only two cases displayed recurrence of the frenum. None of the three pre-pubescent cases required additional intervention, maintaining acceptable clinical results after three years. Patient acceptance was very high, and no postoperative adverse events were reported. Received:
Thermal Effects URL  Penn, C., Beninati, C., Mariano, A., Dooley, D. and Harsono, M. Thermal Effects on Pulp Due to Laser and Handpiece Usage Compendium of Continuing Education in Dentistry
Vol. 35(10), pp. e41-44 
2014 rank5
Abstract: The study was designed to compare changes in pulpal temperature during ablation of dental hard tissue while using two established erbium dental laser systems, a new CO2 laser system, and a conventional high-speed handpiece.Eighty non-carious human extracted molars were separated into four sample groups of 20 teeth each. Three laser systems were used, respectively, to ablate the occlusal surface of the teeth in three of the groups for 60 seconds each. The high-speed handpiece was used to drill the occlusal surface of the fourth group for 60 seconds. Pulpal temperatures were measured using thermocouples inserted into each tooth's pulpal chamber prior to ablation.None of the average temperature increases approached the threshold of 5.5°C at which pulpal damage begins. On average, the pulpal temperature of teeth ablated with the Waterlase MD system increased the most (3.56°C). The traditional handpiece caused the lowest average temperature increase (1.57°C), followed by the LightWalker DT system (3.20°C) and the Solea CO2 system (3.30°C).
Restorative, Pain DOI   Poli, R. and Parker, S. Achieving Dental Analgesia with the Erbium Chromium Yttrium Scandium Gallium Garnet Laser (2780 nm): A Protocol for Painless Conservative Treatment. Photomedicine and laser surgery
Vol. 33(7), pp. 364-371 
2015 rank5
Abstract: OBJECTIVE: The aim of this research is to evaluate those techniques and optimal parameters of Erbium Chromium Yttrium Scandium Gallium Garnet (Er,Cr:YSGG) laser use in delivering predictable painless (or with very limited discomfort) restorative cavity preparation without the aid of injected local anesthesia. MATERIAL AND METHODS: This study was conducted on 30 patients (26 adults and 4 youth 9-16 years old; average age, 37) treated in a private practice. For each patient, a single cavity was prepared using the Er,Cr:YSGG laser (2780 nm). An Electric Pulp Tester (EPT) was used to monitor the changes in pulp sensibility threshold. The patient experience was tested before and after the treatment using a modified Visual Analogue Scale (VAS) and Children's Fear Survey Schedule-Dental Subscale (CFSS-DS) to evaluate pain and anxiety. RESULTS: Pain analysis indicated that 80% of patients (24 out of 30) felt no pain and no discomfort, or only a very slight sensation. None of the 30 patients requested anesthesia. EPT was found to be unreliable in evaluating pulpal pain threshold levels. A tendency was noted wherein greater discomfort was felt by anxious patients. On average, the older the patient, the less discomfort was felt. The factors that have a greater tendency to promote discomfort were: posterior teeth, greater caries depth, greater use of higher power levels and ablation time. CONCLUSIONS: Using the Er,Cr:YSGG laser, it was possible to avoid local anesthesia during cavity preparation with a bur. The treatment was effective in a high number of cases (80%), leading to reduction in the anxiety frequently associated with dental care.
Restorative, Pain DOI URL  Polonsky, M., Gutknecht, N. and Franzen, R. Review of possible predictors for pain perception with class 1–5 cavity preparations using Er,Cr:YSGG laser: a retrospective clinical in vivo study Lasers in Dental Science
Vol. 1(1), pp. 9-21 
2017 rank5
Abstract: Aim
The study recorded 400 responses from 301 patients, aged 6–93, who all had carious lesions prepared with the erbium, chromium: yttrium-scandium-gallium-garnet (Er,Cr:YSGG) 2780-nm laser system. Different parameters, including gender, delivery method, power settings, tooth position, class type of cavity preparation, and patients’ age, were compared and analyzed for possible predictive values in anticipating the patients’ pain experience.

Methods
Class 1–5 cavity preparations were made using the Er,Cr:YSGG laser. All carious lesions fit ICDAS code 4–5 classifications. Power setting of 3.75 W was used for posterior teeth class 1–4 preparations and 2.5 W for all primary teeth, permanent anterior teeth, and all class 5 preparations. Non-anxious patients, who agreed to start cavity preparation without a local anesthetic, were instructed to stop the procedure and ask for an anesthetic injection, should they perceive a level of pain greater than their tolerance level. Anxious patients were not included in this study. Pain perception using the visual analog scale (VAS) along with the percentage of patients who needed a local anesthesia injection were recorded. The data was then analyzed using one-way ANOVA test, at significance level of α = 0.05, and Tukey pair-wise comparison, at 95% confidence interval.

Results
Eighty-five percent of cavity preparations were pain free; 15% of the preparations were found to have a degree of pain associated with them. However, only 6% requested a local anesthetic injection. There was no significant difference found between the two methods of delivery: gold handpiece (HP) vs. turbo HP. No significant differences were observed between males and females, regarding pain perception (13% vs. 18%, respectively). Posterior teeth were significantly more sensitive to laser cavity preparation, compared to anterior teeth, as indicated by the VAS pain scores (P value = 0.0001). Regarding anterior teeth, class 5 was significantly more sensitive to laser cavity preparations, when compared to class 1. In posterior teeth, there were no statistically significant differences between class 1 and 5, although pain perception was the most prevalent in class 2 preparations. Using higher-power settings (3.75 W vs. 2.5 W) for cavity preparation, the resulting pain response was significantly higher, as indicated by the VAS pain scores (P value = 0.0001). As the patients’ age increases, the frequency of those experiencing pain decreases, with the exception of a sudden spike for the cohort aged 26–35, who proved to be the most sensitive to laser cavity preparation; this group was significantly different from all other age groups (P value = 0.0001).

Conclusions
The Er,Cr:YSGG laser system is an effective method for pain-free cavity preparations for 85% of the general patient population, who do not suffer from dental anxiety. Certain patient selection criteria, including age, power settings, and class type of cavity preparation, are important in achieving an overall positive and pain-free expedience.
Demineralization DOI   Rabelo, J.S., Ana, P.A., Benetti, C., Valério, M.E.G. and Zezell, D.M. Changes in dental enamel oven heated or irradiated with Er,Cr:YSGG laser. Analysis by FTIR Laser Physics
Vol. 20(4), pp. 871-875 
2010 rank4
Abstract: Abstract This study evaluated the change that occurs in dental enamel under action of oven heating or Er,Cr:YSGG laser irradiationnaiming to obtain a structure more resistant to demineralization. Enamel powder was obtained from bovine teeth. Samples werensubjected to oven heating at temperatures of 200, 400, 600, 800, and 1000°C or during laser irradiation with energy densitiesnof 7.53, 10.95, and 13.74 J/cm2. The infrared thermography was used to measure the surface temperature generated in the solid samples of enamel during lasersnirradiation. The samples were analyzed by Fourier transform infrared spectroscopy (FTIR), which shows changes on enamel ovennheated or laser irradiated, due to treatments, related to carbonates, adsorbed water and hydroxyl content. These compositionalneffects were more evident in lased samples. These changes may alter the material properties such as its solubility, and decresenof demineralization that is important for caries prevention.
Apicoectomy, Endo, Restorative DOI   Rahimi, S., Yavari, H.R., Shahi, S., Zand, V., Shakoui, S., Reyhani, M.F. and Pirzadeh, A. Comparison of the effect of Er, Cr-YSGG laser and ultrasonic retrograde root-end cavity preparation on the integrity of root apices. Journal of oral science
Vol. 52(1), pp. 77-81 
2010 rank4
Abstract: The aim of this study was to compare the effect of Waterlase laser and ultrasonic root end cavity preparation on the integrity of root end in extracted human teeth. The canals of 60 extracted maxillary central incisors were cleaned, shaped, obturated and 3 mm of the root end was resected and examined for the presence of any cracks. Class I root-end cavities were then prepared using an ultrasonic unit or Waterlase laser. In the ultrasonic group, KIS 2D tip and medium intensity and in the laser group, 600 mum laser tips and an output power setting of 4 W with 55% water and 65% air were used to prepare the cavity which was studied for the presence of any cracks or chippings. One crack was found in the ultrasonic group, while no cracks were observed in the laser group. There was no significant difference between the two groups (P > 0.05). As for the chipping effect, seven cases (23%) had chipping after cavity preparation in the ultrasonic group but no chipping was found in the specimens of the laser group and the difference was statistically significant (P < 0.05). According to the results of this in vitro study, laser preserves the integrity of root-end cavities better than ultrasonic devices from the standpoint of producing chipping.
Restorative DOI   Rizoiu, I., Kohanghadosh, F., Kimmel, A.I. and Eversole, L.R. Pulpal thermal responses to an erbium, chromium: YSGG pulsed laser hydrokinetic system Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology, and Endodontology
Vol. 86(2), pp. 220-223 
1998 rank5
Abstract: PROBLEM: Laser systems are known to raise pulpal temperatures when applied to tooth surfaces. Dental biocalcified tissues can be cut with an erbium,chromium:yttrium-scandium-gallium-garnet laser-powered hydrokinetic system. This device is effective for caries removal and cavity preparation in vitro. Pulpal monitoring of temperature changes during hard tissue cutting by a hydrokinetic system have not been reported. OBJECTIVES: This study compared the effects of hydrokinetic system, dry bur, and wet bur tooth cutting on pulpal temperature. STUDY DESIGN: In vivo thermocouple intrapulpal measurements were made on cuspid teeth in anesthetized beagle dogs. In vitro measurements were made on extracted human molar teeth preserved in high-salt solution and later rinsed in phosphate-buffered saline (pH 7.4) to simulate in vivo conditions. The hydrokinetic system was compared with conventional air-turbine-powered bur cutting. The hydrokinetic system cuts and bur preparations were randomly made on the buccal surfaces at the cervical one third of the crown and extended until exposure of the pulp was confirmed clinically. RESULTS: Pulpal temperatures associated with the hydrokinetic system either showed no change or decreased by up to 2 degrees C. Wet bur preparations resulted in a 3 degrees to 4 degrees C rise. With dry bur preparations, a 14 degrees C rise in temperature was recorded. CONCLUSIONS: Under the conditions of this study, the erbium,chromium:yttrium-scandium-gallium-garnet laser-powered hydrokinetic system, when used for cavity preparation, had no apparent adverse thermal effect as measured in the pulp space.
Bonding URL  Rossi, R.R., Aranha, A.C., Eduardo, C.d.P., Ferreira, L.S., Navarro, R. and Zezell, D.M. Microleakage of glass ionomer restoration in cavities prepared by Er,Cr:YSGG laser irradiation in primary teeth Journal of Dentistry for Children
Vol. 75(2), pp. 151-157 
2008 rank4
Abstract: Purpose: The purpose of this study was to evaluate microleakage of cavity preparation in primary teeth made with an Er,Cr:YSGG laser (L) or high-speed drill (HD) and conventional (CGIC) and resin-modified glass ionomer cement (RMGIC). Methods: One hundred primary teeth were divided into 10 groups (N=10): (a) groups 1 and 2 represented cavities prepared by a no. 1012 diamond bur with HD; (b) groups 3 through 10 represented cavities prepared with an Er,Cr:YSGG laser (with a repetition rate of 20 Hz power settings varying for enamel=2.5 W and 3 W and dentine=1.0 W and 1.5 W). After cavity preparation, samples were restored with CGIC (Ketac Molar Easy Mix) and RMGIC (Vitremer), impermeabilized, thermal cycled, stained, washed, and sectioned. The degree of dye penetration was scored by 3 standardized examiners using a light stereoscope at X30 magnification. Results: The Kruskal-Wallis test detected no statistical differences between the cavity preparation methods (P<.049). Neither of the GICs tested were able to avoid microleakage, and the RMGIC showed the lowest statistical degree of microleakage compared with CGIC for both types of cavity preparation. Conclusions: The Er,Cr:YSGG laser provided an equivalent method of cavity preparation compared to the high-speed drill. The resin-modified glass ionomer cement showed the lowest degree of microleakage. This restorative material should be considered when choosing the cavity preparation method.
Microstructure / Mineral Content DOI   Secilmis, A., Usumez, A., Usumez, S. and Berk, G. Evaluation of mineral content of enamel prepared by erbium , chromium : yttrium – scandium – gallium – garnet laser Lasers in Medical Science
Vol. 25, pp. 467-472 
2010 rank5
Abstract: The aim of this study was to evaluate the mineral content of enamel etched at two different power settings with an erbium, chromium:yttrium–scandium–gallium–garnet (Er,Cr:YSGG) laser. Buccal, lingual and mesial or distal surfaces of five premolar teeth were cut, and three enamel slabs were obtained from each tooth. Fifteen enamel specimens were divided into three groups (1 W, 2 W and control) of five specimens each and subjected to Er,Cr:YSGG laser. The mean percentage weights of the five elements [calcium (Ca), potassium (K), magnesium (Mg), sodium (Na) and phosphorus (P)] in each slab were measured by inductively coupled plasma-atomic emission spectrometry (ICP-AES). One way analysis of variance (ANOVA) was used to analyze differences among the groups (1 W, 2 W and control). There were no significant differences among the groups (1 W, 2 W and control) for Ca, K, Mg, Na, or P, or for the Ca/P ratio (P > 0.05). Scanning electron microscopy (SEM) photographs indicated that the surface irregularities increased with increased power setting. Laser treatment did not affect the mean percentage weights of Ca, K, Mg, Na, and P, or the Ca/P ratio, in any group.
Bonding URL  Shahabi, S., Chiniforush, N., Bahramian, H., Monzavi, A., Baghalian, A. and Kharazifard, M.J. The effect of erbium family laser on tensile bond strength of composite to dentin in comparison with conventional method Lasers in Medical Science
Vol. 28(1), pp. 139-142 
2013 rank4
Abstract: The purpose of this study was to evaluate the effect of Er:YAG and Er,Cr:YSGG laser on tensile bond strength of composite resin to dentine in comparison with bur-prepared cavities. Fifteen extracted caries-free human third molars were selected. The teeth were cut at a level below the occlusal pit and fissure plan and randomly divided into three groups. Five cavities were prepared by diamond bur, five cavities prepared by Er:YAG laser, and the other group prepared by Er,Cr:YSGG laser. Then, all the cavities were restored by composite resin. The teeth were sectioned longitudinally with Isomet and the specimens prepared in dumbbelled shape (n = 36). The samples were attached to special jigs, and the tensile bond strength of the three groups was measured by universal testing machine at a speed of 0.5 mm/min. The results of the three groups were analyzed with one-way ANOVA and Tamhane test. The means and standard deviations of tensile bond strength of bur-cut, Er:YAG laser-ablated, and Er,Cr:YSGG laser-ablated dentine were 5.04 ± 0.93, 13.37 ± 3.87, and 4.85 ± 0.93 MPa, respectively. There is little difference in tensile bond strength of composite resin in Er,Cr:YSGG lased-prepared cavities in comparison with bur-prepared cavities, but the Er:YAG laser group showed higher bond strength than the other groups.
Bonding DOI   Shahabi, S., Ebrahimpour, L. and Walsh, L.J. Microleakage of composite resin restorations in cervical cavities prepared by Er,Cr:YSGG laser radiation Australian Dental Journal
Vol. 53(2), pp. 172-175 
2008 rank5
Abstract: BACKGROUND: Evaluation of microleakage is important for assessing the success of new methods for surface preparation and new adhesive restorative materials. The aim of this laboratory study was to assess microleakage at the margins of composite restorations in Er,Cr:YSGG laser prepared cavities on the cervical aspects of teeth by means of dye penetration, and compare this with conventionally prepared and conditioned cavities. METHODS: Class V cavities were produced on sound extracted human teeth, which had been assigned randomly to one of three groups (N = 10 each), as follows: Group 1 - prepared using a diamond cylindrical bur and then treated with 37% phosphoric acid; Group 2 - irradiated with an Er,Cr:YSGG laser (Biolase Waterlase) and then treated with 37% phosphoric acid; Group 3 - irradiated only with the laser. After application of bonding agent (Excite, Ivoclar Vivadent), all cavities were restored with composite resin (Heliomolar). After polishing the restorations, the teeth were thermocycled from 5-50 degrees C for 500 cycles. Dye leakage was assessed after immersion in methylene blue, by examining longitudinal sections in a stereomicroscope at x 30 magnification. RESULTS: The extent of dye penetration was lowest in the laser only group (Group 3). Penetration of dye to dentine and axial walls occurred in 80 per cent of conventionally prepared (bur + acid) specimens, but in the laser group, dye penetration to the axial wall occurred in only 30 per cent of cases. There was a strong statistical association between treatment group and the distribution of microleakage scores (Chi-square, P = 0.0023). CONCLUSIONS: For Class V cavities, with the adhesive materials employed, higher microleakage occurs with phosphoric acid etching of bur- or laser-cut surfaces, than with the surface created by use of the laser alone without additional conditioning.
Microstructure / Mineral Content URL  Shahabi, S. and Zendedel, S. Atomic analysis and hardness measurement of the cavity prepared by laser Lasers in Medical Science
Vol. 25, pp. 379-383 
2010 rank3
Abstract: The purpose of this study was to compare the compositional changes and microhardness of the cavity floor prepared by erbium, chromium:yttrium–scandium–gallium–garnet (Er,Cr:YSGG) laser irradiation with those of the conventional bur-prepared cavity. A total of 16 extracted human molar teeth (with no carious lesions or repairs) were selected for this study. On the buccal and lingual (palatal) surfaces of each tooth, cavities (diameter 3 mm, depth 2 mm) were prepared with an Er,Cr:YSGG laser system (Waterlase MDTM, USA) and high-speed turbine. The cavities were cross-sectioned and subjected to atomic analysis by scanning electron microscopy–energy dispersive X-ray spectrometry (SEM-EDX) and Vickers hardness test. Statistical analyses were performed with t-tests. Surface characteristics of the prepared cavities were also investigated by SEM. No significant differences were found between the calcium/phosphorus (Ca/P) ratio and Vickers hardness of laser- and bur-prepared cavities. The SEM observation revealed that the lased cavity surface was irregular, and there was also an absence of smear layer; the orifices of dentinal tubules were exposed. Microhardness measurement of the cavity floor confirmed that the Er,Cr:YSGG laser produced a clean-cut surface of the cavity.
Bonding URL  Staninec, M., Gardner, A.K., Le, C.Q., Sarma, A.V. and Fried, D. Adhesion of composite to enamel and dentin surfaces irradiated by IR laser pulses of 0.5-35µs duration Journal of Biomedical Materials Research
Vol. 79B(1), pp. 193-201 
2006 rank5
Abstract: The characteristics of laser-treated tooth surfaces depend on the laser wavelength, pulse duration, spatial and temporal laser beam quality, incident fluence, surface roughness, and the presence of water during irradiation. Ablated surfaces are most commonly restored with adhesive dental materials and the characteristics of the ablated surfaces influence adhesion of restorative materials. Previous studies suggest that high bond strengths can be achieved using shorter laser pulses that minimize peripheral thermal damage. In this study, Er:YSGG, Er:YAG, and CO2 lasers were used at irradiation intensities sufficient to simulate efficient clinical caries removal to uniformly irradiate bovine enamel and human dentin surfaces using a motion control system with a microprocessor-controlled water spray. The degree of spatial overlap of adjacent pulses was varied so as to investigate the influence of irradiation uniformity and surface roughness on the bond strength. Composite resin was bonded to the irradiated surfaces and shear bond tests were used to obtain bond strengths in MPa. The highest results were obtained using the Er:YAG pulses with pulse durations less than 35 μs without the necessity for postirradiation acid etching. Some of these groups were not significantly different from nonirradiated, acid-etch-only positive control groups.
Restorative URL  Straßl, M., Üblacker, B., Bäcker, A., Beer, F., Moritz, A. and Wintner, E. Comparison of the emission characteristics of three erbium laser systems - a physical case report Journal of Oral Laser Applications
Vol. 4(4), pp. 263-270 
2004 rank3
Abstract: The physical characteristics of pulsed radiation delivered by three different commercially available Erbium
laser systems were investigated. To collect real field data and avoid the evaluation of "laboratory values"
provided by many manufacturers. each of the systems chosen has been in practical use for at least 6 months. The
results are compared to the physical requirements for cavity preparation with the least collateral damage.
Bonding URL  Sungurtekin-Ekci, E. and Oztas, N. Microtensile bond strength of a resin-based fissure sealant to Er,Cr:YSGG laser-etched primary enamel Odontology
Vol. 104(2), pp. 163-169 
2015 rank5
Abstract: The aim of this study was to evaluate the effect of Er,Cr:YSGG laser pre-treatment alone, or associated with acid-etching, on the microtensile bond strength of a resin-based fissure sealant to primary enamel. Twenty-five human primary molars were randomly divided into five groups including (1) 35 % acid etching, (2) 2.5-W laser etching, (3) 3.5-W laser etching, (4) 2.5-W laser etching + acid etching, and (5) 3.5-W laser etching + acid etching. Er,Cr:YSGG laser was used at a wavelength of 2.780 nm and pulse duration of 140–200 μs with a repetition rate of 20 Hz. Following surface pre-treatment, the fissure sealant (ClinPro™, 3M Dental Products) was applied. Each tooth was sectioned and subjected to microtensile testing. Kruskal–Wallis test was used for statistical analysis. The level of significance was set at p < 0.05. The microtensile bond strength values of group 1 were significantly higher than those of group 2, while no statistically significant difference was detected between groups 1, 3, 4, and 5. It was concluded that 3.5-W laser etching produced results comparable to conventional acid etching technique, whereas 2.5-W laser etching was not able to yield adequate bonding performance.
Bonding URL  Tachibana, A., Marques, M.M., Soler, J.M.P. and Matos, A.B. Er,Cr:YSGG laser for caries removal: influence on bonding of a self-etching adhesive system Lasers in Medical Science
Vol. 23(4), pp. 435-441 
2008 rank4
Abstract: This study evaluated the influence of the dental substrates obtained after the use of different caries removal techniques on bonding of a self-etching system. Forty, extracted, carious, human molars were ground to expose flat surfaces containing caries-infected dentine surrounded by sound dentine. The caries lesions of the specimens were removed or not (control—G1) either by round steel burs and water-cooled, low speed, handpiece (G2), or by irradiation with an erbium, chromium:yttrium scandium gallium garnet (Er,Cr:YSGG) laser (2W, 20 Hz, 35.38 J/cm2, fiber G4 handpiece with 0.2826 mm2, non-contact mode at a 2 mm distance, 70% air/20% water—G3) or using a chemo-mechanical method (Carisolv—G4). Caries-infected, caries-affected and sound dentines were submitted to a bonding system followed by construction of a resin-based composite crown. Hour-glass shaped samples were obtained and submitted to a micro-tensile bond test. The bond strength data were compared by analysis of variance (ANOVA), complemented by Tukey's test (P ≤ 0.05). The samples of sound dentine presented higher bond strengths than did samples of caries-affected dentine, except for the groups treated with the Er,Cr:YSGG laser. The highest bond strengths were observed with the sound dentine treated with burs and Carisolv. The bond strengths to caries-affected dentine were similar in all groups. Additionally, bonding to caries-affected dentine of the Er,Cr:YSGG laser and Carisolv groups was similar to bonding to caries-infected dentine. Thus, caries-affected dentine is not an adequate substrate for adhesion. Moreover, amongst the caries removal methods tested, the Er,Cr:YSGG laser irradiation was the poorest in providing a substrate for bonding with the tested self-etching system.
Restorative URL  Türkün, M., Türkün, L.S., Celik, E.U. and Ateş, M. Bactericidal effect of Er,Cr:YSGG laser on Streptococcus mutans. Dental materials journal
Vol. 25(1), pp. 81-6 
2006 rank5
Abstract: The aim of this study was to compare the antibacterial activities of Er,Cr:YSGG laser with two different power outputs against a chlorhexidine gluconate-based cavity disinfectant. A cavity tooth model test was used to determine the antibacterial activity. Four cylindrical cavities were prepared on the dentin surface of 10 bovine incisors and left in contact with Streptococcus mutans for 72 hours to allow bacterial invasion. Following which, Er,Cr:YSGG laser with 0.75 W and 1 W power outputs and a chlorhexidine gluconate-based cavity disinfectant were applied separately on one of the three infected cavities, whereas the fourth was left untreated for control. Standardized amounts of dentin chips were obtained from the cavity walls, and the number of bacteria recovered was counted. Statistical analysis was carried out using one-way ANOVA and Dunnett's C test (p=0.05). No significant differences were observed among the data obtained from the chlorhexidine gluconate-based cavity disinfectant and the two Er,Cr:YSGG laser groups (p>0.05). However, when compared to the control group, both Er,Cr:YSGG laser groups and the chlorhexidine gluconate-based cavity disinfectant resulted in significantly less bacterial recovery (p<0.05). In conclusion, the antibacterial activity on S. mutans demonstrated by Er,Cr:YSGG laser with both energy outputs was similar to that of the tested chlorhexidine gluconate-based cavity disinfectant.
Bonding DOI   Üşümez, S., Orhan, M. and Üşümez, A. Laser etching of enamel for direct bonding with an Er,Cr:YSGG hydrokinetic laser system American Journal of Orthodontics and Dentofacial Orthopedics
Vol. 122(6), pp. 649-656 
2002 rank5
Abstract: Irradiation of enamel with laser energy changes the physical and chemical characteristics of the enamel surface, and these alterations hold promise for the conditioning of enamel for bonding procedures. This laboratory study examined the influence of laser irradiation of enamel at 2 different power settings with an erbium, chromium: yttrium, scandium, gallium, garnet (Er,Cr:YSGG) hydrokinetic laser system (Millennium System, Biolase Technology, Inc; San Clemente, Calif) on the shear bond strength of orthodontic appliances and compared these with that of acid-etching. The prepared surfaces of 40 noncarious, intact, extracted premolars were exposed to laser energy: 20 teeth at 2-W setting (5.6 J/cm2) and 20 teeth at 1-W setting (2.7 J/cm 2) of the commercial laser unit. Twenty teeth were etched with 37% orthophosphoric acid. Brackets were bonded with an orthodontic no-mix adhesive, and shear bond strength was determined with a universal testing machine. Data were analyzed with Kruskall-Wallis and Mann-Whitney U tests. Etched and restored surfaces of an acid-etched tooth and a 2-W laser-irradiated tooth were examined with scanning electron microscopy (SEM). Laser treatment under 2 W resulted in bond strengths of 7.11 ± 4.56 megapascals (MPa), which was not significantly different from that of acid etching (8.23 ± 2.30 MPa). Laser irradiation at 1 W resulted in bond strengths of 5.64 ± 3.19 MPa, which was significantly different from that of acid etching (P < .05). However, large SD and coefficient of variation values of both laser groups made reliability of this method as an enamel conditioner questionable. Scanning electron microscopy studies of the restored irradiated surfaces showed good surface characteristics, whereas the lased surface was still more irregular than the restored acid-etched sample. Although laser devices are effectively used in some other areas of dentistry, enamel conditioning with an Er,Cr:YSGG laser cannot be considered a successful alternative to the conventional methods of increasing bond strengths to enamel. Copyright textcopyright 2002 by the American Association of Orthodontists.
Restorative DOI   Yazici, A.R., Baseren, M. and Gorucu, J. Clinical comparison of bur- and laser-prepared minimally invasive occlusal resin composite restorations: two-year follow-up Operative Dentistry
Vol. 35(5), pp. 500-507 
2010 rank5
Abstract: This study evaluated the two-year clinical performance of two minimally invasive cavity preparation techniques, bur and laser, in Class I occlusal resin composite restorations. Twenty-seven patients, each having at least one pair of occlusal caries, were enrolled in this study. For each patient, one of the cavities was prepared with a diamond bur, and the other was prepared with Er, Cr:YSGG laser. The cavities were restored with a nanofilled flowable resin composite, Grandio Flow, using an etch-and-rinse adhesive, Solobond M. A total of 108 restorations were placed in molars by a single operator. The restorations were evaluated according to modified Cvar/Ryge criteria. The evaluations were performed at baseline, 6, 12, 18 and 24 months after initial placement by two calibrated operators. The Chi-square and Fisher's exact test were used for statistical analysis. All the patients were available during all evaluated periods, resulting in a recall rate of 100%. The retention rates of the restorations at 24 months were 98.1% for bur and 100% for the laser-prepared group. After 24 months, 5.6% of the bur-prepared and 7.4% of the laser-prepared restorations were rated Bravo in marginal discoloration (p > 0.05). Bur-prepared (9.3%) and laser-prepared (13%) restorations were rated Bravo in marginal adaptation (p > 0.05). There were no significant differences between the two cavity preparation techniques regarding the evaluated parameters (p > 0.05). Both cavity preparation techniques performed equally, with excellent outcomes after a 24-month period.
Bonding DOI   Yazici, A.R., Yildirim, Z., Antonson, S.A., Kilinc, E., Koch, D., Antonson, D.E., Dayangaç, B. and Özgünaltay, G. Comparison of the Er,Cr:YSGG laser with a chemical vapour deposition bur and conventional techniques for cavity preparation: A microleakage study Lasers in Medical Science
Vol. 27(1), pp. 23-29 
2012 rank5
Abstract: The aim of this study was to compare the effects of the Er,Cr:YSGG laser using chemical vapour deposition (CVD) bur cavity preparation with conventional preparation methods including a diamond bur and a carbide bur on the microleakage with two different adhesive systems. A total of 40 extracted human premolars were randomly assigned to four experimental groups according to the cavity preparation technique: group I diamond bur (Diatech); group II carbide bur (Diatech); group III Er,Cr:YSGG laser (Biolase Millennium II); and group IV CVD bur (CVDentUS). Using the different preparation techniques, Class V standardized preparations were performed on the buccal and lingual surfaces with gingival margins on the dentin and occlusal margins on the enamel. Each preparation group was randomly assigned to two subgroups (five teeth, ten preparations) according to the type of adhesive: an etch-and-rinse adhesive (Adper Single Bond), and a singlestep self-etch adhesive (AdheSE One). All preparations were restored with a nanohybrid composite resin in a single increment. Following thermocycling (×500; 5-55°C), the teeth were immersed in basic fuchsin and sectioned in the orovestibular direction. Dye penetration was evaluated under a light microscope by two blinded examiners. Data were statistically analysed with the Kruskal-Wallis and Wilcoxon tests (P<0.05). There were no statistically significant differences between the preparation techniques with either of the two adhesive systems (pP>0.05). Comparing the enamel and dentin leakage scores within each group, no statistically significant differences were found (pP>0.05). The Er,Cr: YSGG laser cavity preparation did not differ from preparation with CVD, diamond or carbide bur in terms of microleakage with the different adhesive systems. textcopyright 2010 Springer-Verlag London Ltd.
Hypersensitivity URL  Yilmaz, H.G., Cengiz, E., Kurtulmus Yilmaz, S. and Leblebicioglu, B. Effectiveness of Er,Cr:YSGG laser on dentine hypersensitivity: a controlled clinical trial Journal of clinical periodontology
Vol. 38(4), pp. 341-346 
2011 rank5
Abstract: Aim: Attempts have been made to treat dentine hypersensitivity (DH) with lasers. However, there is limited knowledge on the effects of erbium, chromium-doped:yttrium, scandium, gallium and garnet (Er,Cr:YSGG) laser on DH. The aim of this study was to evaluate the efficacy of Er,Cr:YSGG laser on reduction in DH. Methods: Forty-two patients (146 teeth) were included. Teeth were assigned to an experimental group and irradiated with the Er,Cr:YSGG laser. In the control group same clinical instrument was used without laser emission. DH was assessed for both groups utilizing the visual analog scale. Plaque index (PI) scores were recorded immediately following treatment, at 1 week, 1 and 3 months. Results: The results showed that Er,Cr:YSGG laser irradiation had a significantly higher desensitizing effect compared with the placebo immediately after treatment (p<0.05). Intra-group comparisons revealed no statistically significant differences within the placebo group (p>0.05). For the test group, the differences between baseline and all time points following treatment were statistically significant (p<0.05). No significant differences were observed in PI between the test and control groups at any follow-up examination (p>0.05). Conclusion: Within the limits of this study, it appears that Er,Cr:YSGG laser is effective in the treatment of DH compared with the placebo treatment.
Cavity Prep URL  Yu, D.-g., Kimura, Y., Kinoshita, J.-I. and Matsumoto, K. Morphological and atomic analytical studies on enamel and dentin irradiated by an Erbium, Chromium:YSGG laser Journal of clinical laser medicine & surgery
Vol. 18(3), pp. 139-143 
2000 rank4
Abstract: Objective: The purposes of this study were to investigate the morphological and atomic analytical changes and to evaluate the cutting effect on dental hard tissues of this laser in vitro. Background Data: There have been few reports on morphological and atomic analytical study of dental hard tissues after erbium,chromium: yttrium,scandium,gallium,garnet (Er,Cr:YSGG) laser irradiation. Methods: Eighteen extracted human molars were sectioned into 3-mm-thick slices, which were irradiated with water-air spray by an Er,Cr:YSGG laser at 6.0 W and 20 Hz for 5 sec for enamel and 5.0 W and 20 Hz for 5 sec for dentin. The samples were then morphologically observed and examined atomic-analytically. Results: Regular holes having sharp edges and smooth walls, but no melting or carbonization, were observed in both samples. An atomic analytical examination showed that the calcium ratio to phosphorus showed no significant changes between the lased areas and unlased areas (p > 0.01). Conclusion: These results showed that the Er,Cr:YSGG laser has a good cutting effect on dental hard tissues and offers advantages of no burning or melting after laser irradiation.