YSGG Laser Research Articles

Effect of laser application on microtensile bond strength of an orthodontic adhesive to water-aged composite.

This study evaluated the microtensile bond strength (MTBS) of an orthodontic adhesive to water-aged composite surfaces using different surface treatments. Twelve composite blocks (10 mm × 10 mm × 5 mm) were fabricated and randomly divided into two groups. Half of the specimens were stored in distilled water for 1 day, and the other specimens were stored for 30 days. The specimens were randomly assigned to six groups according to surface treatments (n = 15): Group 1, control (no treatment); Group 2, phosphoric acid; Group 3, diamond bur; Group 4, diamond bur + phosphoric acid; Group 5, laser; and Group 6, laser + phosphoric acid. One coat of orthodontic adhesive was bonded to one surface of composite blocks, and a microhybrid composite resin was bonded to the surfaces via a Teflon mold. Bond strength was evaluated using an MTBS test. Surface topography was evaluated using scanning electron microscopy (SEM) analysis. The data were analyzed using one-way analysis of variance, Tamhane post-hoc test, and independent sample t-tests (P < 0.05). Bond strength values tended to decrease in all groups (with the exception of Group 2) after storage in water for 30 days (P < 0.05). Laser and diamond bur application (with or without phosphoric acid) enhanced the bond strength. An Er,Cr:YSGG laser application may be a feasible alternative to diamond bur for enhancing the bond strength of orthodontic adhesive to composite resin.

Evaluation of Dental Anxiety in Patients Undergoing Second-Stage Implant Surgery with Er,Cr: YSGG Laser Treatment: Randomized Clinical Trial

Evaluation of Dental Anxiety in Patients Undergoing Second-Stage Implant Surgery with Er,Cr: YSGG Laser Treatment: Randomized Clinical Trial

Dentin bond strength of bioactive cement in comparison to conventional resin cement when photosensitized with Er,Cr:YSGG Laser.

Objective:The purpose of the present study was to assess dentin shear bond strength (SBS) and mode of bond failure of bioactive cement (BA) in comparison to conventional resin cement when photosensitized by Er,Cr: YSGG Laser (ECL).Methods:The present in-vitro study was carried out from March 2019 to May 2019. Sixty permanent non-carious, intact, non-fractured molars were isolated and mounted vertically in acrylic resin. Buccal surface of each molar tooth was ground, polished and surface treated with ECL. Ketac conditioner was applied on the surface washed and air dried surface. Tetric -N-Bond adhesive was applied on forty-five samples and light cured. The specimens were allocated into four groups (n=15) according to the type of cement used i.e., Calibra (C), BA, Variolink II (V) and Maxcem-Elite (ME). For SBS testing was performed using the universal testing machine. Eight samples from each group were assessed for modes of failure. Means and standard deviations were compared using analysis of variance (ANOVA) and Tukey’s post hoc test at a significance level of p < 0.05.Results:The highest mean SBS was observed in group ECL-C (21.55±3.08). The lowest mean SBS was displayed in group ECL-ME (14.25±3.55). Mean SBS values for group ECL-C (21.55±3.08) and group ECL-V (20.74±4.15) were comparable (p <0.05). Similarly, SBS values of group ECL-BA (15.48±3.62) and group ECL-ME (14.25±3.55) were comparable (p <0.05).Conclusion:Dentin surface conditioned with Er,Cr: YSGG and bonded to C and V cements exhibit favourable bond strength values.

Enhanced high-slope-efficiency and high-power LD side-pumped Er:YSGG laser.

We designed a high-slope-efficiency and high-power laser diode (LD) side-pump Er:YSGG laser based on the analysis for the effect of the crystal dimension and the LD distribution on the temperature and energy distributions in laser crystal. A maximum output power of 34.9 W for a 2.8 µm mid-infrared laser was achieved at 200A, 120 Hz, and 500 µs pulse width, corresponding to the slope efficiency of 13.7% and optical-optical efficiency of 12.7%. Moreover, the beam quality $M_x^2/M_y^2$Mx2/My2 factors of the laser were measured to be 5.15/5.19 and the far-field divergences ${\Theta _x}/{\Theta _y}$Θx/Θy were 9.52/9.75 mrad.

Lithium di silicate ceramic surface treated with Er,Cr:YSGG and other conditioning regimes bonded to orthodontic bracket

AimTo assess bond integrity and modes of failure of metallic brackets to lithium disilicate ceramics (LDC) conditioned with Er,Cr:YSGG laser (ECL). Material and methodsSixty LDC were arbitrarily allocated into six groups (n = 15) according to the type of ceramic surface conditioning treatment. Group 1 surface treated with silane (S) only, group 2 surface etched with hydrofluoric acid (HF)+ S, group 3 surface conditioned with HF+ ultrasonic bath (UB)+ S, group 4 sand blasting (SB) of glass ceramic surface with 50 µm Al2O3, group 5 surface conditioned with self-etch ceramic primer (SECP) and in group 6 surface treated with ECL + S. After conditioning, the specimens were positioned in a universal testing device for shear bond strength (SBS) testing. Adhesive Remnant Index (ARI) was used to determine sites of bond failure. Among experimental groups analysis of variance (ANOVA) and Tukey multiple comparison test was used at a significance level of (p < 0.05). ResultsThe highest SBS values were observed in group 3 HF+ UB + S (18.21 ± 1.241) and the lowest SBS values were displayed group 1 surface treated with S only (5.21 ± 0.23). Specimens surface conditioned in group 2 with HF+ S (17.85 ± 1.25), group 3 HF+ UB + S (18.21 ± 1.241) and group 6 ECL + S (17.09 ± 1.114) unveiled comparable SBS values (p > 0.05). ConclusionLDC conditioned with ECL at (4.5 W and 30 Hz) has a potential to be used in clinical settings alternate to HF acid.

Sub-ablative laser irradiation to prevent acid demineralisation of dental enamel. A systematic review of literature reporting in vitro studies.

Caries lesions begin with enamel acid demineralisation mediated by microorganisms. Lasers with sub-ablative energy might act as a prophylactic intervention to reinforce enamel against lesions caused by acid. A systematic review of the literature was performed evaluating only in vitro studies published from 2010 to 2018. The research was performed using the following databases: Medline, Embase and the Web Of Science. A further search was performed consulting the list of references of the included studies as well as book chapters which dealt with this topic. A total of 347 records were retrieved and, after their evaluation, 36 studies were included. CO2 lasers were the most described and effective device in preventing acid demineralisation. This type of laser was unique in improving the already positive results obtained with fluoride-based interventions. Er,Cr:YSGG (with fluencies > 8.5J/cm2), diode and argon lasers also improved enamel acid resistance (p-values ranging from 0.05 to 0.001) producing similar effects with fluoride-based interventions. Regarding the sealant retention outcome, the Er:YAG laser was able to perform an enamel etching which was as effective as the traditional acid etching with the advantage of being easier and usually well accepted by low-compliant patients (i.e. younger children). Nd:YAG presented the worst results. The most common structural changes after the laser irradiation were water and carbonate reduction in the enamel combined with a phosphate and calcium enamel content increase. Moreover, the calcium/phosphate ratio was found to reach the 1.67 ideal ratio. The in vitro studies that examined the prophylactic use of lasers for increasing enamel acid resistance presented interesting results that are enough to support a further in vivo experiment. This would entail the use of a clinical laser as an alternative or in combination with fluoride-based interventions.

Does the application of surface treatments in different sintering stages affect flexural strength and optical properties of zirconia?

To investigate the influence of surface treatments conducted in presintering and postsintering stages on flexural strength and optical properties of zirconia. Specimens were milled from partially sintered zirconia blocks in different geometries and divided into three main groups as presintered, postsintered, and control groups. Test groups were further divided into three subgroups (n = 10) according to the surface treatments conducted (grinding, Er,Cr:YSGG laser irradiation, air-borne particle abrasion [APA]). Four-point flexural strength (σ) test and Weibull analysis were conducted. Color differences (ΔE00 ) and translucency parameter (TPab ) were calculated with a spectrophotometer. Surfaces of specimens were scrutinized under FESEM. Data were statistically analyzed. Postsintered groups exhibited higher σ values (P < .05). Within all groups, highest and lowest σ values were detected at postsintered and presintered APA groups, respectively (P < .05). All ΔE00 values were above the perceptibility threshold (ΔE00 > 0.8). Higher TPab values were obtained and deeper scratches were observed in presintered groups. Surface treatments performed at postsintering stage had a favorable effect on the flexural strength of all specimens. Surface treatments performed before sintering increased translucency and caused higher ΔE00 values. Surface treatments performed at different sintering stages can alter mechanical and optical properties of zirconia.

Effects of motion direction and power of Er,Cr:YSGG laser on pull-out bond strength of fiber post to root dentin in endodontically-treated single-canal premolar teeth

BackgroundInadequate retention and gradual debonding of intracanal post from root dentin is a major cause of failure of endodontically treated teeth restored with fiber post.Main bodyThis study aimed to assess the effect of surface treatment of quartz fiber posts with different powers and motion directions of Er,Cr:YSGG laser on their pull-out bond strength to root dentin in endodontically treated premolar teeth. In this study, 105 fiber posts were divided into 7 groups according to their surface treatment with different powers of Er,Cr:YSGG laser at 2780 nm wavelength, 20 Hz frequency and 150 μs pulse duration in circumferential (C) or longitudinal (L) motion directions: Control group (no treatment), 0.5 W laser in longitudinally (L0.5), 1.0 W laser in longitudinally (L1), 1.5 W laser in longitudinally (L1.5), 0.5 W laser in circumferentially (C0.5), 1.0 W laser in circumferentially (C1) and 1.5 W laser in circumferentially (C1.5). After cementation, pull-out bond strength was measured in Newton (N). Each sample was inspected under a stereomicroscope at × 25 magnification to determine the mode of failure. Two samples of each group were inspected under a scanning electron microscope (SEM). Data were analyzed using two-way ANOVA and Tukey’s test with significant level of 0.05. The pull-out bond strength of 0.5 W groups had significant differences with the control group (P = 0.009). The bond strength of 1.0 W and 1.5 W groups were not significantly different (P = 0.630) but were higher than the control and 0.5 W groups (P < 0.001). Motion direction of laser irradiation had no significant effect on the bond strength (P = 0.384). The interaction effect of power and motion direction of laser irradiation had no significant effect on the bond strength (P = 0.092).ConclusionFiber posts treated with 0.5, 1.0 and 1.5 W Er,Cr:YSGG laser showed higher bond strength to dentin compared to posts with no surface treatment. However, the motion directions of laser irradiation had no significant effect on the bond strength. In order to minimize damage to post surface and achieving maximum bond strength, longitudinal surface treatment of posts with 1.0 W power of Er,Cr:YSGG laser is recommended.

Removal of osseointegrated dental implants: a systematic review of explantation techniques.

This systematic review aims to evaluate current literature regarding available techniques for removal of osseointegrated implants in terms of explantation's success, complications, and bone loss. Two reviewers conducted a systematic literature search through electronic databases (PubMed and EMBASE), complimented by manual and grey literature searches. Successful explantation was defined as the primary outcome. Complications and availability of residual bone for immediate implantation were defined as secondary outcomes. Eighteen articles, comprising 372 implants and 241 patients, were included. Five techniques were identified: reverse torque, trephines, burs, piezosurgery, and laser-assisted explantation. Peri-implantitis was the most common reason for explantation, followed by crestal bone loss, fracture, and malpositioning. The reverse torque was the most frequently reported technique (284 implants) with 87.7% success rate. Burs were used for explantation of 49 implants with a 100% success rate, while trephines were utilized for removal of 35 implants with 94% success. Piezosurgery (11 implants) and Er.Cr:YSGG laser (1 implant) showed 100% success. One study reported perforation of the sinus floor following trephine explantation, while another reported fracture of 3 implants following reverse torque application. Further analysis was hindered by the quality of the available studies and their lack of data. Reverse torque seems the most conservative, and in the authors' opinion, should be the first choice for explantation despite its inferior success rate. Additional studies with randomized controlled designs and larger sample sizes are required. Dental implants have become the leading choice to replace missing teeth with gradually increasing numbers of complications and failures. An effective, conservative, and economic explantation technique is necessary to allow a successive implant placement.

Comparison of Enamel Acid Etching And Er, Cr: Ysgg Laser Etching on The Shear Bond Strength of Stainless Steel Orthodontic Brackets (an in Vitro Study)

Comparison of Enamel Acid Etching And Er, Cr: Ysgg Laser Etching on The Shear Bond Strength of Stainless Steel Orthodontic Brackets (an in Vitro Study)

Effect of acid etching, Er, Cr: YSGG laser conditioning and combining on shear bond strength of orthodontic metal bracket

The present study aims to evaluate the shear bond strength and the adhesive remnants index (ARI) of metal brackets. For this purpose, enamel etched with acid, Er; Cr: YSGG (2780 nm) laser, and a combination of them. In this study, 60 human premolars were divided into three groups (acid, Er, Cr: YSGG (2780 nm) laser, and combined etching). Each group contains 20 teeth. For testing of shear bond strength (SBS), the force applied by a universal testing machine. All the samples were examined under a light stereomicroscope to determine the bond failure mode. The results revealed that the laser-acid group had the maximum mean shear bond strength while the acid group had the minimum shear bond strength. The values of mean shear bond strength obtained of 25.90, 16.94, and16.60 MPa for laser-acid, laser, and acid, respectively. Laser and acid groups were negligibly different from each other, while they were significantly different from the lasers–acid group (p < 0.05). Regardless of the preparation of the enamel, bond failure occurred predominantly in the enamel-adhesive site. Er, Cr: YSGG (2780 nm) laser conditioning in combination with acid led to high shear bond strength, but the hazardous effect on tooth should be considered. The bond failure mode was almost similar among all three groups, where there was no adhesive left on the surface of the tooth.

Influence of Er,Cr:YSGG Laser Dentin Conditioning on the Bond Strength of Bioactive and Conventional Bulk-Fill Dental Restorative Material.

Objective: The aim of the study was to evaluate shear bond strength (SBS) and modes of failure for bioactive (BA) material when bonded to Er,Cr:YSGG lased dentin in comparison with other conditioning regimes. Materials and methods: One hundred twenty extracted teeth were mounted and allocated into eight groups (n = 15) according to the surface conditioning [group 1: Er,Cr:YSGG laser + BA; group 2: Er,Cr:YSGG laser + multi-core (MC); group 3: Er,Cr:YSGG + Ketac Conditioner (polyacrylic acid) + BA; group 4: Er,Cr:YSGG + Ketac Conditioner + MC; group 5: conventional etch and rinse + BA (Control); group 6: conventional etch and rinse + MC (Control); group 7: self-etch + BA; group 8: self-etch + MC]. Based on the type of bulk-fill material, samples from groups 1, 3, 5, and 7 were bonded to BA and groups 2, 4, 6, and 8 were bonded to conventional MC bulk-fill material. All specimens were tested for SBS using universal testing machine. Ten samples from each group were assessed for modes of failure. Data were assessed using analysis of variance and Tukey multiple comparisons test. Results: The maximum SBS value was in group 6 (18.96 ± 0.315) with etch and rinse dentin conditioning and bonded to MC. The minimum SBS value was exhibited by group 7 (16.04 ± 0.854) self-etch conditioning bonded to BA. SBS among group 6 specimens were significantly higher than that of specimens in group 7 (p < 0.05). Among all groups the most common type of observed failure was adhesive. Conclusions: Dentin surface treatment with Er,Cr:YSGG phototherapy for the adhesive bonding of BA and conventional bulk-fill resin composite MC showed comparable bond strength outcomes to conventional conditioning techniques. Er,Cr:YSGG laser dentin conditioning of dentin for bonding of bulk-fill BA materials has potential to be used clinically as it shows potential for adequate adhesive bond integrity.

Enamel Conditioning by Phosphoric Acid and Er.Cr: YSGG Laser Irradiation - EDS and SEM Studies

This study evaluated the effects of ortophosforic acid and Er.Cr: YSGG LASER on human enamel by means of a field emission in-lens scanning electron microscope. The materials used for conditioning the teeth were SE�35% (Scotchbond� Etchant Phosphoric Acid) and MG6-MZ6 tips with Er, Cr: YSGG laser, 30% water, 60% air, 5.5 W/20 Hz according to manufacturer�s instructions. The acid time of action determines enamel demineralization in all situation. Er.Cr: YSGG laser treatment of non-carious enamel, a laser power of 5.5 W is found to be the optimal to improve the micromorphology of enamel.

Influence of Er,Cr:YSGG Laser Irradiation on the Push-Out Bond Strength of Zirconia and Glass Fiber Posts with Radicular Dentin.

Objective This in vitro study was designed to evaluate the influence of an Er,Cr:YSGG laser on the bond strength of zirconia and glass fiber posts with root dentin. Materials and methods Ninety extracted single-rooted human teeth were randomized into 6 groups (n = 15/group) on the basis of different posts (zirconia/glass fiber) and Er,Cr:YSGG laser tips (axial and radial). Specimens were prepared for push-out testing with the help of a cutting machine; six slices (2 on each cervical, middle, and apical) of approximately 1 mm thickness were sectioned for all roots on a plane perpendicular to the long axis of the post. All specimens were placed into a universal testing machine with a defined 0.5 mm/min crosshead speed until the maximum failure load was obtained. Results The highest mean push-out bond strength of the glass fiber and zirconia groups was achieved with laser treatment. The highest push-out bond strength was achieved with the axial fiber tip (7.63 ± 1.22 MPa), and the lowest was achieved with a radial fiber tip of the glass fiber group (6.98 ± 0.96 MPa). ANOVA showed a statistically significant difference between the groups (p = 0.041). The mean push-out bond strength was found to be higher with an axial fiber tip for both cervical and apical segments in the glass fiber and zirconia groups (p < 0.05). The independent t-test resulted in the overall highest mean push-out bond strength in the apical segments (p = 0.026). Conclusion Within the limits of the present in vitro research study, an enhancement in the push-out bond strength of resin cement, mainly in the cervical region of the root canal, was achieved after irradiation with an Er,Cr:YSGG laser using an axial fiber tip.

Abstracts from the 7th Congress of the World Federation for Laser in Dentistry European Division June 20–22, 2019 Parma, Italy

Abstracts from the 7th Congress of the World Federation for Laser in Dentistry European Division June 20–22, 2019 Parma, Italy

Shear Bond Strength of Composite Resin and Conventional Flowable Composite in Primary Molars Prepared by Bond prep mode and Cutting mode Er, Cr:YSGG Laser (an in vitro study)

Introduction: Recently laser usage became popular in pediatric dentistry due to its efficiently in cutting enamel and dentin without pain, and with lesser vibration and noise, which leads to roughness in the structure of dental tissue like the etching process, which is the first indication for composite restorations cavity preparation. Due to the morphological differences and heterogeneous composition, of primary teeth compared to permanent teeth, the parameters of laser should be differently set. Materials and methods: This study was conducted to evaluate and compare the effect of bond prep mode and cutting mode of Er, Cr: YSGG laser in primary molars on shear bond strength of composite resin and conventional flowable composite using applied on flattened buccal and lingual surface on forty-eight freshly extracted sound natural deciduous molars divided into 2 groups and each group is subdivided into 2 subgroups each according to the mode of preparation: into: group 1: bond prep mode Er,Cr:YSGG laser which were further divided into: subgroup A: composite resin and subgroup B: conventional flowable composite, and group 2: cutting mode Er,Cr:YSGG which were further divided into: subgroup A: composite resin and subgroup B: conventional flowable composite. The samples were subjected to universal testing machine. Results: The mean (SD) values for shear bond strength of Bond prep and cutting modes regardless of restorative material were 22.8 (2.7) and 19.4 (2.7), respectively. Bond prep mode showed statistically significantly higher mean shear bond strength than cutting mode (P-value <0.001, Effect size = 0.296). The mean (SD) values for shear bond strength of composite resin and conventional flowable composite regardless of preparation mode were 20.7 (3.1) and 21.4 (3.3), respectively. There was no statistically significant difference between the two restorations (P-value = 0.394, Effect size = 0.017). Conclusion: The bond prep mode is better than cutting mode, Er,Cr:YSGG Laser irradiation improves shear bond stress and no significant difference between composite resin and conventional flowable composite clinically.

Influence of photobio-modulation with an Er,Cr: YSGG laser on dentin adhesion bonded with bioactive and resin-modified glass ionomer cement.

One hundred and twenty extracted human molars were allocated in eight groups (n = 15) based on surface conditioning and cement type. Specimens of groups 2 and 6 were conditioned with ECL whereas, groups 3 and 7 were treated with ECL + ethylenediamine tetra acetic acid (EDTA). Specimens in groups 4 and 8 were surface conditioned by ECL + EDTA + Tetric-N-Bond, and groups 1 and 5 were considered as control (non-surface treated). Cement build-ups were performed on the surface-treated dentin with BAC (groups 1-4) and RMGIC (groups 5-8). A universal testing machine was used to measure the SBS and the mode of failure was evaluated using a stereomicroscope. Statistical analysis was performed using an analysis of variance and Tukey's post hoc test, at a significance level of p < 0.001. The highest SBS values were observed in group 8, ECL + EDTA + Tetric-N-Bond + RMGIC (21.54 ± 3.524 MPa) and the lowest SBS values were displayed by group 1, with no surface treatment and BAC application (11.99 ± 0.821 MPa). The majority of failures were found to be mixed in lased dentin-treated dentin surfaces. BAC when bonded to dentin surfaces conditioned with ECL showed lower SBS in comparison to RMGIC. Conditioning of dentin with ECL and a bonding agent (Tetric-N-bond) improved bond strength scores for BAC and RMGIC. Use of EDTA improved bond strength values when bonded to BAC and RMGIC; however, this improvement was not statistically significant.

The assistance of Er,Cr:YSGG laser in pulp injury related to anterior teeth trauma

Background: Erbium chromium or erbium lasers constitute preferred instruments for the preparation of that section of tooth adjacent to the pulp chamber rather than high-speed drills, especially in cases of dental injury. Their advantages can support modified operations in achieving optimum recovery and avoiding complications related to the healing process. Purpose: The aim of the study was to describe another modality of the assistance of erbium, chromium:yattrium-scandium-gallium-garnet (Er,Cr:YSGG) laser in traumarelated pulp injury affecting the anterior teeth. Case(s): The results of laser treatment applied to four pulp injuries of three children were analyzed in this case report. Case Management: Er,Cr:YSGG laser-assisted cavity preparation was performed without resort to a local anesthetic, the cavities being sealed with mineral trioxide aggregate (MTA). None of the cases demonstrated symptomatic or peri-radicular pathology during clinical or radiographic examinations. Conclusion: The results contained in this case report support the application in pediatric dentistry of a Er,Cr:YSGG laser to pulpotomy cavities as part of the treatment of traumatic pulpal injuries to permanent incisors.

Powerful 3-μm lasers acousto-optically Q-switched with KYW and KGW crystals.

We report, to the best of our knowledge, the first use of KY(WO4)2 and KG(WO4) acousto-optical Q-switches in 3-μm powerful lasers. Q-switches of two different designs (normal incidence with antireflection coatings, and Brewster-angle cut crystals) operate in lasers based on Er:YAG, Cr:Yb:Ho:YSGG, and Cr:Er:YSGG laser crystals. Gain and lifetime of laser crystals significantly influence the regime of Q-switched generation. Er:YAG and Cr:Yb:Ho:YSGG lasers deliver pulses with 10.8mJ and 17.5mJ energy, respectively. Pulses with energy of 29.6mJ and duration of 75ns in the TEM00 mode are obtained in a Cr:Er:YSGG laser. The energy is scaled up to 85.7mJ in the two-stage master oscillator power amplifier system. Powerful laser systems of this kind are in the region of interest for pumping other mid-IR laser media (e.g., Fe:ZnSe and Fe:CdSe), OPOs, CO2 lasers, and amplifiers. Preliminary experiments on microstructuring of transparent materials by the laser-induced backside wet etching method demonstrate the potential of such lasers to build the foundation for dye-free tissue and cell engineering concepts.

Use of the Er,Cr:YSGG laser for removing remnant adhesive from the enamel surface in rebonding of orthodontic brackets.

The aim of this study was to compare the use of the Er,Cr:YSGG laser with the use of adhesive-removing pliers for removing remnant adhesive from the enamel surface. A total of 54 sound premolars were divided into two groups of 27. Each group was assigned one of two adhesive removal systems: the Er,Cr:YSGG laser, and adhesive-removing pliers. Shear bond strength was measured 24h after bracket bonding, with the bracket bonding/debonding and residual adhesive removal procedures repeated twice after the first adhesive removal. Before the first bonding and after each adhesive removal procedure, the average surface roughness (Ra) of each tooth was measured. Additionally, 14 of the premolars were examined under a scanning electron microscope. There were no significant differences in the shear bond strength between the two removal systems or between the three debonding sequences. There were significant differences in the enamel surface roughness after each removal sequence between the adhesive removal systems, and a significant increase in the enamel surface roughness was noted in each group with successive removal sequences. The scanning electron microscope images revealed evaporation of the primer and adhesive on the enamel surface and laser etching of enamel in the laser removal group, and the remnants of primer and adhesive on the enamel surface after each removal sequence in the plier removal group. The Er,Cr:YSGG laser was useful for removing remnant adhesive from the enamel surface for bracket rebonding.