Search

Background: The fear of pain during the various stages of orthodontic treatment with fixed appliances is a common concern of patients. Therefore, the present research aimed to thoroughly investigate the impact of bracket architecture on pain perception during active treatment, debonding, and adhesive removal., Materials: One hundred consecutive patients who completed treatment with one of two bracket systems (2-slot brackets with an integral base or conventional twin brackets with foil mesh) were included in this prospective cohort study. Participants were asked to evaluate the level of pain encountered throughout their orthodontic treatment with the fixed appliances and during bracket and adhesive removal, utilizing a 0-10 numerical rating scale. Two different methods of bracket removal (bracket debonding pliers and Lift-Off Debonding Instrument) and adhesive removal (adhesive removal pliers and rotary instrument) were tested., Results: Our study found moderate and comparable levels of pain during active treatment in both groups (4.4 ± 1.6 in the 2-slot group and 3.9 ± 1.9 in the Twin group). Debonding of brackets with integral base caused more discomfort compared to conventional twin brackets and using bracket removal pliers elicited more pain sensations than when Lift-Off Debonding Instrument were employed. Patients are likely to prefer adhesive removal methods involving rotary instruments despite the sound and vibrations produced by contra-angle handpiece., Limitations: The lack of randomization in patient grouping introduces an increased risk of bias., Conclusions: The results of the present study suggest that the bracket architecture, particularly the construction of the bracket base, affects the level of discomfort experienced during debonding., Trial Registration: ClinicalTrials.gov, NCT06324162, Registered 20 March 2024-Retrospectively registered, https://clinicaltrials.gov/study/NCT06324162., (© The Author(s) 2024. Published by Oxford University Press on behalf of the European Orthodontic Society.)

Background: The removal of adhesive remnants after bracket debonding has been shown to cause damaging effects on the enamel surface. This study aimed to investigate the efficacy of stained adhesive remnant removal (ARR) on enamel roughness compared to translucent composite., Material and Methods: Thirty extracted premolar teeth were divided equally into three groups; conventional composite control group (CC), stained composite group (SC) and stained bonding solution group (SB). The buccal surface of each tooth was cleaned, dried and the surface roughness (Ra) was evaluated using a contact prophylometer (T0). After bracket debonding, a high-speed carbide bur under a water-cooling system was used for ARR in one direction and the time consumed for ARR was recorded. After ARR, the second mean Ra values were recorded (T1). The samples were then polished using polishing paste with low-speed rubber cup and the third mean Ra values were recorded (T2)., Results: Repeated one-way ANOVA revealed a significant difference in the mean Ra values at T0, T1 and T2 within each group P<0.05. A statistically significant difference in the changes of the mean Ra values after ARR (T1-T0) and after polishing (T1-T2) was found between the CC group and both SC and SB groups. A significant difference in the time consumed for ARR was found between the three groups with CC group being the most time-consuming group., Conclusion: Stained composite material followed by the stained bonding solution provided better visibility during ARR with lower mean Ra values and less time for ARR compared totranslucent composite material., (Copyright © 2024. Published by Elsevier Masson SAS.)

Background: The aim for this research was to evaluate and compare the impact, bond strength, and residual adhesive on the enamel surface after debonding of different orthodontic molar tubes. The tested materials were metal, composite, and newly introduced ceramic orthodontic molar tubes., Materials and Methods: In all, 66 first molar teeth were randomly divided into three groups. Metal, glass-fiber composite and ceramic orthodontic molar tubes were bonded and shear bond strength (SBS) tests were performed. The adhesive remnant index (ARI) scores after debonding were recorded and the enamel surfaces were investigated using scanning electron microscopy (SEM) after the adhesives were cleaned., Results: The mean SBS values of the metal and ceramic tube groups were significantly higher than that of the glass-fiber composite tube group. The highest SBS values were recorded for the ceramic tube group (11.09 ± 2.51 MPa). Failure typically occurred at the adhesive-enamel interface in the ceramic group, whereas the majority of the samples in the glass-fiber composite group showed failure at the adhesive-tube base interface according to ARI and SEM investigations. ARI 1 and ARI 2 scores were commonly observed for the metal tube group., Conclusions: All the molar tubes tested had generated clinically acceptable SBS values; however, the values for glass-fiber composite molar tubes were significantly lower than those for the ceramic and metal molar tubes. If the debonding procedure is performed carefully, the ceramic molar tubes may be an enamel-safe product for patients seeking fully esthetic orthodontic treatment., (© 2023. The Author(s), under exclusive licence to Springer Medizin Verlag GmbH, ein Teil von Springer Nature.)

Objective: This article aims to review the safety and efficacy of the Er:YAG laser in debonding dental accessories. Methods: This review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Articles published between 2010 and 2022 on the removal of dental accessories using erbium laser were searched. The selected articles were then classified according to the accessories used: adhesives, brackets, restorations, or implant crowns. Enamel surface roughness, shear bond strength, adhesive remnant index, duration time (t), pulp chamber temperature (T), morphology (M), and other variables were then noted. Results: The dental accessories and adhesives used were described along with the laser parameters used, such as frequency, pulse width, irradiation time, scanning mode, water-air cooling, and other variables. Conclusions: Laser removal using Er:YAG laser of dental accessories such as brackets, crowns, and veneers is fundamentally safe, time-saving, and does not cause damage to the enamel nor the underlying dentin. However, there was no distinct advantage with laser removal seen, such as those residual adhesives of brackets on the tooth surface and temporary adhesives of restorations.

Polishing after the removal of brackets is the final step in orthodontic treatment. It is simple to perform, though some studies have reported that polishing causes damage to the enamel surface. An in vitro study was made of the influence of the buccal surface convexity of the tooth upon possible enamel loss when the remaining resin and adhesive are removed after bracket decementing using two different polishing modes: a tungsten carbide bur at low and high speeds. The convexity of the buccal surface was quantified in 30 incisors and 30 premolars. A stereoscopic microscope was used to obtain photographs of the profile of the crown, and Image J software was used to calculate convexity by dividing the length of a line from the cementoenamel junction to the incisal margin by another line from the mentioned junction to the maximum convexity of the buccal surface. Brackets were cemented on all the teeth and were decemented 24 h later. In both groups, the residual composite was removed with a tungsten carbide bur at a low speed in one-half of the teeth and at a high speed in the other half. The buccal surface of each tooth was then photographed again, and the convexity was calculated and compared against the baseline value. The difference between the two values were taken to represent the enamel loss. The convexity of the premolars was significantly greater than that of the incisors, but this did not result in greater enamel loss when the same polishing mode was used. However, the tungsten carbide bur at a high speed proved more aggressive, causing significantly greater enamel loss than when used at a low speed.

Objective: This study aimed to evaluate enamel surface integrity and time consumed during residual cement removal after bracket debonding using different adhesive removal burs with and without a dental loupe., Material and Methods: Sixty human-extracted premolars were collected, cleaned, mounted, and prepared for orthodontic bracket bonding. Teeth were randomly divided into three main groups (n = 20) based on the adhesive removal method: tungsten carbide system (TC), sof-lex discs system (SD), and diamond system (DB) groups. Then, each group was subdivided into two subgroups (naked eye and magnifying loupe subgroups). The brackets were bonded and then debonded after 24 h, and the Adhesive Remnant Index (ARI) was assessed. The adhesive remnants were removed by different systems, and the final polishing was performed by Silicone OneGloss. The enamel surface roughness was evaluated before bracketing (T0), after residual cement removal (T1), and finally after polishing (T2) using surface Mitutoyo SJ-210 profilometry and Scanning Electron Microscopy (SEM) to determine the Enamel Damage Index (EDI) score. The time consumed for adhesive removal was recorded in seconds., Results: The Kruskal Wallis test showed a statistically significant difference in roughness values at T1 compared to T2 between subgroups (p < 0.001). When comparing EDI at T1 and T2, the Kruskal-Wallis H-test showed statistically significant differences in all subgroups. The pairwise comparisons revealed that EDI scores showed a statistically significant difference at T1 and T2 between DB vs. TC and SD (p = 0.015) but not between TC vs. SD (p = 1.000), indicating the highest roughness value observed in the DB group. The time for cement removal was significantly shorter in the magnifying loupe group than in the naked eye group and was shortest with the TC group, whereas the time was the longest with the DB group (p < 0.05)., Conclusion: All three systems were clinically satisfactory for residual orthodontic adhesive removal. However, TC system produced the lowest enamel roughness, while the DB system created the greatest. The polishing step created smoother surfaces regardless of the systems used for resin removal., (© 2024. The Author(s).)

Purpose: To compare the debonding time of IPS e.max CAD lithium disilicate glass-ceramic veneers in different thickness and transparency using Er:YAG laser, and evaluate the effect of Er:YAG laser on the surface topography of the veneers and the underlying tooth., Methods: A total of twelve maxillary first premolar teeth were collected and prepared, then veneers were made by computer aided design and computer aided manufacture(CAD/CAM) system. The veneers were divided into four groups according to different thicknesses and transparency: e.max HT with 0.5 mm and 1.0 mm thickness, e.max LT with 0.5 mm and 1.0 mm thickness. Three veneers of each group were cemented to prepared premolar with resin cement and then stored in normal saline solution at room temperature for 7 days. All veneers were debonded with Er:YAG laser and the debonding time of all-ceramic veneers of all groups was recorded. Scanning electron microscopy(SEM) observation was performed to detect the surface topography of the veneers and the underlying tooth. SPSS 19.0 software package was used for statistical analysis., Results: The debonding time of 1.0 mm-thick groups were longer than 0.5 mm-thick groups. When the veneer thickness was 0.5 mm, the average debonding time of e.max LT group was longer than e.max HT. Consistent with the finding of 0.5 mm, the longer debonding time was found in the e.max LT group of 1.0mm. No cracks and crater structure were found in SEM observation of veneers after Er:YAG laser irradiation. Teeth surface was covered with bonding cement with no signs of ablation or damage of the enamel., Conclusions: Er:YAG laser can completely debond lithium disilicate glass-ceramic veneers, and the debonding time depends on the transparency and thickness of the veneers. The lower translucent porcelain veneers (e.max LT) and thicker ones (1.0 mm-thick) had a longer debonding time. Moreover, Er:YAG laser does not damage the morphology and topography of the veneer and the teeth surface.

This study used seven different adhesive removal systems to evaluate and compare enamel surface integrity, heat generation, and time consumed during residual cement removal after de-bracketing. The sample size was 140 human premolars. Teeth were cleaned, mounted, and prepared for orthodontic bracket bonding. Brackets were then debonded using bracket-removing pliers. Teeth were randomly assigned to seven groups based on the residual cement removal system: Group 1: Stainbuster bur, Group 2: Renew diamond bur #129, Group 3: Renew carbide bur, Group 4: OneGloss Complete system, Group 5: Sof-Lex system, Group 6: Enhance Finishing and PoGo Polishing complete kit, and Group 7: Renew friction grip points. The enamel surface was evaluated for roughness before bracketing and after residual cement removal using surface profilometry. The time taken for cement removal was recorded using a digital timer, and heat generation was measured using a laser thermometer before and after cement removal. One-way ANOVA compared the pre- and post-values for enamel surface roughness, temperature, and time consumed. When comparing the difference between the post- and pre-finishing roughness using one-way ANOVA, the Renew diamond bur produced the roughest enamel surface post-removal with a mean of 4.716 μm, while the Sof-Lex recorded the lowest at 0.760 μm. The highest mean temperature was recorded with the Stainbuster bur at 5.545 °C, and the lowest temperature was recorded with the Enhance bur at 2.260 °C. The time for cement removal was the shortest with the Enhance bur at 12.2 s, whereas the time was the longest with the Renew diamond bur at 30.4 s. In conclusion, all the residual cement removal systems used in this clinically simulated study were not able to restore the original enamel surface smoothness. However, the 3M Sof-Lex produced the lowest enamel roughness but with more time consumption and heat generation. When selecting the best residual cement removal system to be used, clinicians should weigh the merits and demerits of each system based on the clinical judgement of the operator.

Background: The main goal of orthodontic debonding is to restore the enamel surface as closely as possible to its pretreatment condition without iatrogenic damage. This study aimed to compare the effects of different adhesive removal burs; zirconia burs, tungsten carbide burs, and white stone burs on enamel surface roughness., Materials and Methods: Total sample of 72 extracted premolars was randomly divided into three equal groups (n = 24) depending on the method of adhesive removal: zirconia burs (ZB); tungsten carbide burs (TC); and white stones (WS). The metal brackets were bonded using Transbond XT orthodontic adhesive (3 M Unitek, Monrovia, CA, USA) and debonded after 24 h using a debonding plier, then the ARI was assessed. The adhesive remnants were removed using the different burs and Final polishing was performed using Sof-lex discs and spirals. Thirteen samples from each group were evaluated using a Mitutoyo SJ-210 profilometer to determine average surface roughness (Ra) and three samples from each group were examined under Scanning Electron Microscopy (SEM) to determine EDI score. The evaluations were performed at three time points; before bonding (T0), after adhesive removal (T1) and after polishing (T2) and the time consumed for adhesive removal by burs was recorded in seconds. The data were analyzed statistically by ANOVA, Tukey's test and Kruskal-Wallis H-test., Results: Kruskal-Wallis H-test showed no statistically significant difference of ARI in all studied groups (p = 0.845) and two-way mixed ANOVA revealed that all burs significantly increased surface roughness at T1 compared to T0 (p < 0.001) in all groups with the lowest Ra values were observed in the ZB group, followed by the TC group, and WS group. The fastest procedure was performed with WS, followed by ZB, then TC bur (p < 0.001). After polishing (T2), Ra values showed no significant difference in ZB group (P = 0.428) and TC group (P = 1.000) as compared to T0, while it was significant in WS group (p < 0.001)., Conclusion: zirconia bur was comparable to tungsten carbide bur and can be considered as alternative to white stone which caused severe enamel damage. The polishing step created smoother surface regardless of the bur used for resin removal., (© 2023. The Author(s).)

Lack of standardization of the retention phase has led to many studies of stability of movements and characteristic of retainers, disregarding the enamel repercussions of fixed retention on this phase. This study aimed to analyze different methods of enamel polishing after detachment of orthodontic retainers. Forty-five healthy premolars were divided into three groups according to the polishing bur after debonding, and four specimens without intervention were used as control. A 0.038 × 0.015 inches gold chain was bonded between the premolars and then removed. The adhesive remnant was removed with three types of burs according to the study groups (Group 1: white stone at high speed; Group 2: high-speed handpiece with a 30-blade tungsten carbide bur; Group 3: low-speed handpiece and a 30-blade tungsten bur). After debonding and polishing, all samples were analyzed with a confocal microscopy on surface roughness parameters: Sa: Arithmetic mean of the height of the surface. Rq: Square mean of the height of the surface and Sz: Maximum surface height. Mechanical tests were carried out to determine the bonding stress of the retention adhered to the teeth using an electromechanical testing machine. The adhesion stress was 8.23 MPa (±0.87). The quality of the refinement of the enamel after debonding is essential in order to preserve its integrity. The use of the 30-blade tungsten carbide bur provides a smooth enamel surface after polishing.

Background: During the orthodontic bonding process, the need for repositioning or rebonding of orthodontic brackets on the enamel surface occurs frequently. The aim of this study is to compare the shear bond strength (SBS) in rebonding orthodontic stainless steel brackets with three different methods of enamel surface conditioning methods., Materials and Methods: In this in vitro study, 80 human premolars that were extracted for orthodontic purposes were randomly divided into four groups and underwent orthodontic bonding procedure ( N = 20). Except for the control group, three other groups underwent debonding and rebonding process in which after removing the remaining adhesive with tungsten-carbide bur, enamel surface conditioned by three different methods including re-etching with phosphoric acid, sandblasting + acid etching, and Erbium-doped Yttrium-Aluminum-Garnet laser. Then, the SBS of the bracket to the enamel surface was compared between different groups. Scanning Electron microscopy images were also obtained from a number of samples. Statistical analysis was performed by Kruskal-Wallis and Mann-Whitney tests., Results: The highest SBS was observed in the primary bond (control group) with an average of 29,440 MPa. There was a significant difference between the studied groups ( P < 0.001) and only the group that was re-etched with phosphoric acid had no significant difference with the control group ( P = 0.708) ∝ =0.05., Conclusion: Rebonding of brackets using phosphoric acid for reconditioning of the enamel surface creates bond strength comparable to the primary bond. Other groups had significantly lower SBS than the control group., Competing Interests: The authors of this manuscript declare that they have no conflicts of interest, real or perceived, financial or non-financial in this article., (Copyright: © 2023 Dental Research Journal.)

To investigate whether flash-free adhesive ceramic brackets (FFA) have a better clinical performance than conventional adhesive ceramic brackets (CVA) in patients undergoing multi-bracket orthodontic treatment. PubMed, CENTRAL, Web of Science, Scopus, Embase, CNKI and Grey-literature were searched without restrictions up to January 2022. Both randomized controlled trials (RCTs) and controlled clinical trials (CCTs) were included. Risk of bias assessment was performed using the RoB 2.0 and ROBINS-I cochrane risk of bias tools. Eight articles, for seven studies, were included in this systematic review, and four split-mouth trials (SMT) were included in the meta-analysis. A random-effects meta-analysis found a statistically significant faster bonding time with FFA (mean difference [MD] = -93.85 seconds/quadrant, P = .002, 2 SMT), and no statistically significant difference regarding bracket failure rate at 6 months (risk ratio [RR] = 1.05; P = .93, 3 SMT), adhesive removal time (MD = -18.26 seconds/quadrant, P = .50, 2 SMT), and amount of remnant adhesive (MD = -0.13/bracket, P = .72, 2 SMT) between FFA and CVA. No difference (P > .05, 3 SMT) was found in enamel demineralization and periodontal measurements. CVA showed a statistically significant higher debonding pain score (P = .004, 1 SMT). Both flash-free and conventional adhesive ceramic brackets had a similar clinical performance, except for the faster bonding with FFA. Further, well-designed clinical trials are still required., (© 2022 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Introduction: The objectives of this study were to evaluate the effects of a flash-free (FF) System on (1) the amount of plaque accumulation around the braces on buccal surfaces of the teeth, (2) the time required for the placement of brackets, including the clean-up of the flash, (3) the amount of adhesive left on the tooth after debonding, and (4) time required for adhesive remnant clean-up., Methods: Thirty-six patients (aged 19.96 ± 5.74 years) were randomly distributed to receive adhesive precoat (APC)-FF and APC-Plus ceramic brackets on the maxillary right or left anterior 6 teeth. Bonding and debonding time were measured per segment in milliseconds. A plaque revealer agent was applied to discolor the dental plaque, and a modified plaque accumulation index was used to evaluate the amount of plaque at 2 different time points. An adhesive residue index was used after the debonding., Results: The mean bonding times were 138.87 seconds (8332.47 milliseconds) and 77.82 seconds (4669.31 milliseconds) for APC-Plus and APC-FF, respectively. The difference was statistically significant (P ≤0.001). The difference between the mean debonding times was not statistically significant. A significant difference was found between the adhesive residue index scores of the 2 systems (P ≤0.001). There was no statistically significant difference between plaque accumulation scores at first- and second-time points for both adhesive systems. APC-Plus score (0.94 ± 0.98) was higher than the APC-FF score (0.50 ± 0.91) on the incisal side at the second time point (P ≤0.05)., Conclusions: FF adhesives can be a good alternative to reduce chair time in bonding appointments., (Copyright © 2022 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.)

Introduction: The aim of the study was to assess the time factor and tooth type during premature debond of orthodontic brackets., Material and Method: A retrospective epidemiological study was carried out on adolescents who had benefited from a multi-metal vestibular attachment treatment, having all 6 to 6 teeth bonded to the arch on the day of installation., Results: 333 patients were included. The detachment rate decreased as the treatment progresses. The teeth with most orthodontic debonding were the maxillary first molar, mandibular first molar, mandibular second premolar, and maxillary second premolar. Skeletal class II patients tended to take off more than class I patients. Detachments were significantly more frequent in the mandibular arch in deepbite compared to normalbite patterns, the mandibular second premolar being the tooth at risk. There seems to be a correlation between the quality of oral hygiene and the rate of detachment, regardless of the time of treatment., Discussion: The type of orthodontic movement, the quality of the bonding, the failure to observe the precautions by the patient may affect the date of the detachment. The low coronary height, hygiene, the biting force, the divergence seems to intervene on the type of attachment debonded., Conclusion: The brackets are more particularly debonded at the start of treatment and on the posterior teeth. Anteroposterior and especially vertical dysmorphosis could have an implication in debonding.

Aim: This study aimed to evaluate the impact of using a magnifying dental loupe on enamel surface roughness during adhesive resin removal by different burs., Materials and Methods: Ninety-six extracted premolar teeth were randomly divided according to the bur used with or without the aid of a magnifying loupe into four equal groups ( N = 24): group I: naked eye tungsten carbide burs (NTC); group II: magnifying loupe tungsten carbide burs (MTC); group III: naked eye white stones (NWS); and group IV: magnifying loupe white stones (MWS). The initial surface roughness ( R a ) T0 was evaluated using a profilometer, and the scanning electronic microscopy (SEM) technique. The metal brackets were bonded and debonded after 24 hours with debonding plier. After adhesive removal, R a was evaluated again (T1) also the time spent on adhesive removal was recorded in seconds. The samples were finally polished by Sof-Lex discs and Sof-Lex spirals, and the third R a evaluation was performed (T2)., Results: The results of two-way mixed analysis of variance (ANOVA) showed that all burs increased surface roughness at T1 as compared to T0 ( p < 0.001) with the highest R a values shown in group III followed by group IV, group I, and group II. After polishing, no significant difference was noted in R a values in group I and group II at T0 vs T2 ( p = 1.000), while it was significant in group III and group IV ( p < 0.001). Regarding the time required for adhesive removal, the shortest time was in group IV followed by groups III, II, and I, respectively., Conclusion: The use of a magnifying loupe affects the quality of the clean-up procedure by reducing the enamel surface roughness and the time spent on adhesive removal., Clinical Significance: Using a magnifying loupe was helpful during orthodontic debonding and adhesive removal.

The purpose of this study is to compare bond durability, in terms of fatigue bond strength, of a two-step HEMA-free universal adhesive and representative adhesives in each systematic category. The adhesives used in this study were OptiBond FL, Prime&Bond NT, Clearfil SE Bond 2, G2-Bond Universal, and Scotchbond Universal Plus Adhesive. Fatigue bond strength testing and scanning electron microscopy analysis of adhesively bonded enamel and dentin interfaces were performed. For the adhesives in etch-and-rinse mode, the enamel fatigue bond strength of the G2-Bond Universal adhesive was significantly higher than those of other adhesives, and the dentin fatigue bond strength of Prime&Bond NT was significantly lower than the others. For adhesives in self-etch mode, the enamel fatigue bond strengths of Clearfil SE Bond 2 and G2-Bond Universal were significantly higher than that of the Scotchbond Universal Plus Adhesive, and the dentin fatigue bond strength of G2-Bond Universal was significantly higher than Clearfil SE Bond 2 and the Scotchbond Universal Plus Adhesive. The two-step HEMA-free universal adhesive showed higher enamel and higher or equal dentin fatigue bond strength than other selected representative adhesive systems in etch-and-rinse mode and higher or equal enamel and higher dentin fatigue bond strength than adhesive systems in self-etch mode.

Objective: To determine the effectiveness of different pulse durations (PD) and the water/air (W/A) cooling ratio of the Er:YAG 2940 nm laser that are required for debonding porcelain laminate veneers (PLV), by investigation of the needed time for PLV debonding (DT) and the changes in dental pulp temperature., Materials and Methods: Thirty-six extracted noncarious human maxillary premolars were prepared for receiving PLV. Samples were randomly assigned to six different groups, based on PD and the W/A ratio: Groups A (50 µs, 1:1), B (50 µs, 3:3), C (100 µs, 1:1), D (100 µs, 3:3), E (300 µs, 1:1), and F (300 µs, 3:3). Veneers were debonded using laser irradiation by the same parameters (270 mJ, 15 Hz) with noncontact application mode., Results: All 36 veneers were debonded. Samples of the 50 and 100 µs PDs showed significantly shorter DT (7.4-17 s) than that of the 300 µs which showed significantly the longest DT (104 s) among all other groups (p < .001). However, the highest elevation of pulp temperature was observed in Group E (300 µs, 1:1) which reached (3.4°C)., Conclusion: Using the 50 or 100 µs PD of the Er:YAG laser was more efficient than 300 µs in reducing DT of PLVs with minimal change in pulp temperature. W/A cooling ratio had minimal influence on the DT of PLV., (© 2022 The Authors. Clinical and Experimental Dental Research published by John Wiley & Sons Ltd.)

To examine the effect of mold enclosure and chisel design on macro shear fatigue bond strengths of dental adhesive systems. The fatigue bond strength testing was conducted with two commercially available dental adhesive systems, (1) OptiBond eXTRa and (2) Scotchbond Universal, for bonding a resin composite (Filtek Supreme Ultra) to both enamel and dentin using a mold enclosure and a non-mold enclosure with a knife-edge and two sized notched-edge chisel assemblies for loading. As a loading reference for the fatigue testing, macro shear bond strengths of the adhesive systems to enamel and dentin were conducted using a mold enclosure and a knife-edge chisel assembly. The shear bond strengths with the mold enclosure using knife-edge chisel assembly did not exhibit a significant difference between the adhesive systems for either enamel or dentin. The fatigue bond strengths of bonded specimens demonstrated significant differences when comparing the mold enclosure and non-mold enclosure, but not between knife-edge and notched-edge chisel assemblies. The fatigue bond strengths of dental adhesive systems demonstrated significantly higher values when using mold-enclosed bonded specimens than a non-mold enclosure, regardless of type of chisel assembly., (© 2022 Scandinavian Division of the International Association for Dental Research. Published by John Wiley & Sons Ltd.)

The objectives of this study were to (1) to evaluate the shear bond strength (SBS) of two ceramic brackets when new and when rebonded following various bracket base conditioning methods, and (2) to determine bond failure mode relative to bracket base morphology. 100 Symetri Clear TM (SC) and 100 Radiance Plus ® (RP) ceramic brackets were bonded to bovine incisors and divided into five groups: one group served as controls and four had brackets rebonded following conditioning by: no surface treatment, sealant, sandblasting, and flame then steam. SBS, adhesive remnant index, and bracket base morphology were evaluated. SBS showed no statistical difference between new and rebonded with no surface treatment or sealant (SC brackets) and with sealant or flame and steam (RP brackets). When comparing SC to RP, SBS was higher with SC, no surface treatment, and sandblasted groups. All groups had varying amounts of adhesive left on the tooth, with the sandblasted group having the most. SEM analysis showed that sandblasting damaged the retention features of bracket bases. In conclusion, when rebonded, the SBS of SC brackets that had no surface treatment and both SC and RP brackets that had sealant showed no significant differences to new brackets. Sandblasting damaged the retention features of SC and RP bracket bases, resulting in low SBS.

Aim: A major limitation of indirect bonding is incomplete penetration of the curing light through transfer trays, leading to inadequate curing of light-cure adhesive resin, causing bracket bond failure. Dual-cure adhesive resin is both light and chemically cured, which reduces the requirement of light for curing of the composite. Comparative evaluation of bracket failure rate and bond strength between dual-cure composite and light-cure composite for indirect orthodontic bonding of brackets., Materials and Methods: A split-mouth randomized clinical study was carried out in 51 patients (30 females and 21 males). Indirect orthodontic bonding using Erkogum as adhesive to attach the bracket to cast and glue gun material was utilized to form a transfer tray. Conventional light-cure and dual-cure adhesive resins were compared with regard to their bracket failure rate, adhesive remnant index score, and in vivo clinical bond strength., Results: Kolmogorov-Smirnov test was employed to test the normality of data. Mann-Whitney U test and Chi-square test were performed for the quantitative variables and it was observed that both the groups showed similar results for the parameters being measured. The mandibular arch showed more bracket failure, the dual-cure composite group showed more bracket failure, however, the adhesive remnant index (ARI) score for both the groups was similar. No statistically significant difference was seen concerning the clinical bond strength between the two adhesive resins., Conclusion: Dual-cure adhesive system can be used for indirect bonding in orthodontics. The mandibular arch had a higher bond failure in the second premolar region. The sequence of bond failure was concordant among both the adhesive groups. However, dual-cure adhesive invariably showed more bracket failure. The highest bond strength was observed for the maxillary canine brackets in the light-cure group, and mandibular canine brackets in the dual-cure group. Whereas, the weakest bond strength in the light-cure group was observed for the mandibular second premolar brackets and for maxillary second premolar brackets in the dual-cure group. There was no significant difference between the in vivo clinical bond strength between the two adhesive systems. On debonding, majority of the adhesive was observed to be on the tooth surface., Clinical Significance: This study signifies that both light-cure and dual-cure resins can be used for indirect bonding procedures but light-cure composite resin shows a lower bracket failure rate as compared to dual-cure composite resin.

Objective: This study aimed to evaluate the failure incidence of brackets with at least six months follow-up between self-etch primer and conventional etch/primer, as well as to investigate the clinical duration of the bonding process and the amount of adhesive remnant index (ARI)., Methods: Electronic search was conducted in databases including PubMed, Scopus, Web of Science, ProQuest, ClinicalTrials.gov, and ICTRP (International Clinical Trials Registry Platform). The electronic search targeted only randomized clinical trials and was limited from January 2000 to June 2021. Delphi list is used to evaluate the risk of bias and Stata Version14.2 software was used. This systematic review was conducted according to the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) and recorded on the Ethics Committee of Research Institute of Dental Sciences, SBMU (IR.SBMU.DRC.REC.1398.240)., Results: Out of 2288 extracted studies, 30 of them entered the full-text evaluation process. According to the inclusion criteria, 15 studies entered this systematic review. Containing 607 participants and 10,563 brackets/teeth. All the included studies were of randomized clinical trials (RCT) design with either parallel or split-mouth design. Comparing the two groups, the risk difference effect (RD)=0.007 CI 95% (-0.004,0.018) indicated a neglectable difference in the risk of bracket failure during treatment between the two groups. The index I 2 =53.9% indicated moderate heterogeneity in the results. Furthermore, the P-value=0.007 indicated statistical insignificance between the two interventions in terms of failure rate. The clinical duration of bonding time analysis were equal to SMD &#95;Cohen=-2.67 CI95% (-3.49, -1.85), which indicated a statistically significant reduction in clinical process time, using the self-etch primer. Data synthesis for adhesive remnant index could not be conducted due to heterogeneity among included studies., Conclusions: There was no difference between the self-etch primer and conventional etch/primer in bracket debonding at a medium level of evidence, However, there was statistically significant reduction in clinical bonding time using self-etch primer., (Copyright © 2021 CEO. Published by Elsevier Masson SAS. All rights reserved.)

The premature detachment of orthodontic brackets has consequences for the patient and the practitioner. While the responsibility for the bonding protocol has been widely assessed, the responsibility of the patient is poorly understood. The main objective of the study was to look for patient-specific predictors of metal vestibular attachment detachments. An historical cohort study was carried out from adolescents having benefited from a fixed vestibular appliance treatment lasting 27 months +/- 3 months, having all teeth from first molar to first molar on arch to pose. Univariate and multivariate analyses were performed by logistic regression. 333 patients were included. In univariate analysis, boys tended to take off more than girls, patients in skeletal Class II more than those in Class I, those with at least two cooperative remarks more than those with less than two remarks. The percentage of patients with debonding increases with the number of hygiene remarks. Younger patients were more prone to debond than older patients. The "age" factor has a significant effect in multivariate analysis. Neither the vertical skeletal pattern nor the socio-economic level would intervene in the rate of debonding. The role of patient-specific factors in detachment should be put into perspective. The reliability of the results would be increased by a prospective study using validated indicators of compliance.

Introduction: This split-mouth randomized clinical trial aimed to compare the enamel surface roughness (SR) and color alteration after bracket debonding and polishing using 2 systems., Methods: After removal of excess adhesive using a 12-blade tungsten carbide bur on a low-speed handpiece, a randomized polishing procedure using Sof-Lex discs was applied on 1 side (n = 36) and Sof-Lex Spiral Wheels on the contralateral side (n = 36). Dental replicas were obtained with epoxy resin before bracket bonding and after tooth polishing. The SR was evaluated using a profilometer. The color was assessed using an Easyshade spectrophotometer before bracket bonding, immediately after tooth polishing, and 30 days after polishing. Two-way analysis of variance and t tests were applied for statistical analysis., Results: The SR of enamel showed similar results between the polishing systems (P = 0.309) and between moments (before bracket bonding and after tooth polishing) (P = 0.317). The color change was also similar between the polishing systems (P >0.05)., Conclusions: The Sof-Lex discs and Sof-Lex Spiral Wheel polishing systems used after removal of excess adhesive using a 12-blade tungsten carbide bur on a low-speed handpiece did not appear to significantly damage the enamel surface, and the color change was similar between them., (Copyright © 2021 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.)

Background: Orthodontic debonding procedure produces inevitable enamel surface alterations, sequelae to which are enamel demineralization, sensitivity and retention of pigments. Several agents have been employed to counterbalance the same. The purpose of this study was (1) To evaluate the hypothesis that no significant difference exists in the remineralising potential of nano hydroxyapatite (NanoHAP) dentifrice and fluoridated dentifrice after orthodontic debonding, (2) To estimate the enamel topographic parameters following use of nano HAP dentifrice, post orthodontic debonding., Methods: Sixty upper first bi-cuspids (30 subjects) planned for therapeutic extraction for the orthodontic treatment were bonded with a light cured adhesive. Envelope method of randomisation was followed in this prospective in-vivo study. In each subject, one of the first premolar brackets was debonded using a debonding plier and polished following standard protocols. Envelope method of randomisation was used to determine the side of the premolar to be debonded first. Patient was advised to use fluoridated (Group I) dentifrice for the first 15 days, then the first premolar was covered with a heavy-bodied putty cap, extracted and subjected to atomic force microscopy (AFM). Contralateral first premolar was then debonded and polished using similar protocol, and patient was advised to use nano hydroxyapatite dentifrice (Group II) for next 15 days. The premolar was then extracted and analyzed for surface roughness using AFM. The remineralizing potential of dentifrices was assessed by evaluating surface roughness parameters of the two groups and were compared using a two-sample t test., Results: A significant difference was found amongst Group I (Fluoridated dentifrice) and Group II (NanoHAP dentifrice) (p > 0.001***) for enamel surface roughness variables which reflect remineralising potential of dentifrices. Group II showed significantly lesser value of surface roughness characteristics., Conclusions: NanoHAP dentifrice was shown, after 15 days, to be superior to fluoridated dentifrice in remineralising enamel post orthodontic debonding., (© 2021. The Author(s).)

Introduction: The most used product for surface acid conditioning for enamel is 37-40% phosphoric acid, which promotes greater mechanical retention., Aim: The objective of this study was to compare the shear bond strength (SBS) of brackets bonded to bovine enamel with different acid conditioning protocols and to analyze the surface morphology., Materials and Methods: 169 teeth (n = 13) were divided into 4 groups: control group without conditioning (G1), Dental Gel 37% phosphoric acid (Dentsply) (G2), Ultra Etch 35% (Ultradent) (G3) and Attaque gel 37% (Biodinâmica) (G4). Groups G2, G3 and G4 were subdivided according to the conditioning time into: 10 s (a), 15 s (b), 30 s (c) and 60 s (d). The superficial enamel morphology (n = 3) was analyzed using a scanning electron microscopy (SEM) to analyze the depth of the microporosities. The samples were submitted to the shear test (SBS) with the aid of a universal testing machine (INSTRON) with a speed of 1 mm/min. The enamel after debonding was analyzed to determine the adhesive remnant index (ARI) in a stereoscopic magnifying glass., Statistical Analysis Used: The SBS data were analyzed using two-way ANOVA. ARI data were analyzed using generalized linear models and SEM measurements were analyzed using Kruskal Wallis and Dunn tests. The 95% significance level was used., Results: The SBS within G2, G3 and G4 ranged from 11.11 to 12.66 MPa. ARI score 3 was observed in 35% of the samples. The samples analyzed in the SEM showed microporosity depth rangingfrom 1.28 to 2.48 μm., Conclusions: There was no difference between the acids and times evaluated for SBS. The ARI analysis showed that the studied acids provide protection to the enamel surface, keeping the adhesive attached to the buccal surface after debonding. The increase in conditioning time is directly proportional to the deterioration of the prismatic and interprismatic content., Competing Interests: The authors declare there are no potential conflicts of interest with materials involved in the presente investigation., (© 2020 The Authors.)

The purpose of this study was to evaluate the bonding and wear properties of self-adhesive flowable restorative materials. Five self-adhesive flowable restorative materials were used. The study parameters were: (i) shear bond strengths; (ii) microleakage; (iii) occlusal wear; and (iv) qualitative evaluation of the bonding interface. The range of shear bond strengths of the materials was as follows: 7.4-12.2 MPa to ground enamel, 22.5-32.5 MPa to etched enamel, and 1.3-4.2 MPa to dentin. The microleakage scores of the materials did not show any statistically significant differences regardless of the presence or absence of etching. The wear facets on the materials showed 0.099-0.447 mm 3 of volume loss and 148.6-365.3 µm maximum depth, with statistically significant differences between materials. Scanning electron microscopic images of the interfaces of the materials showed good adaptation regardless of substrate. The bonding and wear properties of self-adhesive flowable restorative materials were still limited and showed lower values than previously reported results for nanofilled composites with an adhesive system. Selective enamel etching can improve the bonding performance of these materials., (© 2021 European Journal of Oral Sciences.)

Materials and Methods: A total of 80 human premolars were included in this study. The samples were first arranged following a standard protocol for bracketing and then debonded using the ultrasonic scaler (US), debonding plier (DP), ligature cutter (LC), and thermal method (TM). Depending on the technique applied for debonding, the specimens were randomly divided into four groups with 20 samples, each keeping a 1 : 1 ratio. During the debonding process, the time taken for each bracket removal was recorded using a stopwatch. To assess the difference in mean time required for debonding among the four techniques, one-way ANOVA test was applied along with Tukey's HSD to compare the two methods., Results: The time range and the mean time required for the four techniques analyzed show that the DP method has the highest range of time needed for debonding with 0.97-2.56 seconds, while LC methods have the least time range taking 0.46 to 1.79 seconds. TM's mean time to debond is the highest at 1.5880 seconds. LC method has the lowest mean debonding time of 0.9880 seconds. The one-way ANOVA test has shown the mean debonding time required by the four techniques to be significantly different ( p < 0.001). Tukey's HSD multiple comparisons also show that the mean time to debond using the LC method is substantially less than the other three methods ( p < 0.001)., Conclusion: The mean debonding time for the TM was substantially the highest, followed by the US and DP. Debonding with the LC technique required the least time. This study shows some limelight towards the effectiveness of the LC method as it is the least time-consuming technique., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2021 Neelutpal Bora et al.)

Objective: This study aims to determine shear debonding strength of metal and ceramic brackets, and the degree of enamel crack healing., Material and Methods: Extracted human maxillary premolars were flattened on the buccal surface, and randomly separated into five groups (n = 15). In control groups (groups 1 and 2), metal and ceramic brackets were bonded on flat polished enamel, while in experimental groups (groups 3 and 4), metal and ceramic brackets were bonded on the surface with boundary where corner cracks were created. Additionally, fifteen specimens (group 5) were also prepared for an indentation procedure with no bracket installation. The degree of crack healing was measured. All brackets were detached with a universal testing machine, and the adhesive remnant index (ARI) was also identified. Healing degree and apparent fracture toughness were then calculated., Results: Between groups with similar bracket types, there was no statistically significant difference in debonding strength. Regarding bracket types, ceramic brackets provided significantly higher debonding strength than metal brackets. There was a significant difference in ARI scores between metal and ceramic brackets. The corner cracks showed signs of healing in both horizontal and vertical directions. No statistically significant difference in the healing rates among the groups was found and the apparent fracture toughness increased from the initial to the final measurement., Conclusions: Within the limitations of this study, even though ceramic brackets required significantly higher debonding force compared to metal brackets, debonding stress was limited to the bonding site and did not affect the surrounding cracks on enamel.

Objectives: To evaluate the effects of adhesive precoated (APC) flash-free brackets on the level of pain, amount of remnant adhesive, and removal time during the debonding procedure., Materials and Methods: Thirty patients (20 female, 10 male) aged 12 to 18 years undergoing nonextraction fixed orthodontic treatment were included in this study. APC flash-free and conventional ceramic brackets were bonded with a split-mouth study design. Bracket types were randomly allocated to quadrants. During the removal of the brackets, the visual analogue scale (VAS) was used to assess the level of pain for each tooth. The adhesive remnant index (ARI) was used to determine the amount of adhesive remaining on the tooth surface. Adhesive removal times were calculated per quadrant. The data were analyzed using the Wilcoxon test for comparisons between groups., Results: Pain scores were generally higher for the conventional group than for the flash-free group. There were no differences in VAS scores across most tooth types during debonding. Overall, ARI results showed more adhesive remnants in the conventional bracket group (P < .001). Except for the right maxillary quadrant, the times required to remove the adhesive were significantly longer for the flash-free brackets than the conventional brackets (P ≤ .005)., Conclusions: Although removal time was slightly longer for the flash-free adhesive than for the conventional adhesive, lower pain scores were generally observed for the flash-free adhesive brackets during the debonding procedure. Both time and pain differences could be considered clinically insignificant., (© 2020 by The EH Angle Education and Research Foundation, Inc.)

Objective: To evaluate enamel roughness and color after debonding flash-free adhesive precoated brackets and brackets coated with conventional orthodontic adhesives using nonbonded enamel as control., Materials and Methods: A total of 80 extracted human premolars were divided into the following four groups: group I: APC TM Flash-Free adhesive precoated brackets; group II: APC TM PLUS adhesive precoated brackets; group III: noncoated brackets, which were coated manually at the time of bonding (all three brackets were Clarity TM Advanced ceramic brackets [3M Unitek, Monrovia, CA, USA]); group IV: nonbonded enamel (control). Bonded premolars were subjected to demineralization, and then brackets were debonded. Each group was then divided into two subgroups to assess enamel around the debonded brackets, and also enamel in the control group, using an atomic force microscope and spectrophotometer. In addition, 12 samples were used to assess the bracket/adhesive/enamel junction with a scanning electron microscope., Results: Mean values of root mean square roughness (Rq) and maximum profile valley depth (Rv) for APC TM Flash-Free, APC TM PLUS, and Clarity TM Advanced groups were 140 nm and 482 nm, 210 nm and 727 nm, and 447 nm and 1243 nm, respectively. All three groups showed higher roughness and depth values than the control enamel. Spectrophotometer results yielded ∆E* of 3.7 ± 0.6, 5.1 ± 0.4, and 7.1 ± 0.6 for APC™ Flash-Free, APC™ PLUS, and Clarity TM Advanced groups respectively. Color coordinates showed progressively higher L* and b* values and progressively lower a* values from group I to group III., Conclusions: Under the same demineralization conditions, enamel around debonded APC™ Flash-Free adhesive precoated brackets showed less roughness and color changes compared to the other two groups.

Objective: This report describes the fluorescence-aided composite removal during lingual bracket debonding with an ultraviolet light emitting diode flashlight. The purpose of this technique is to help clinicians in composite removal without enamel surface damage., Clinical Considerations: The bracket debonding requires clinical attention in order to remove all composites and resins without enamel surface damage. Different protocols can be used in order to minimize the enamel damages and the excess bonding remnants. The fluorescence-aided composite removal permits to have an immediate visualization of the composites and adhesives, especially for the uneven lingual surfaces, of which the interindividual morphological variability is greater than the buccal surfaces., Conclusions: The fluorescence-aided composite removal during lingual brackets debonding minimizes the risks described in literature and it is an easier, more accurate, reliable, noninvasive, inexpensive, and time-saving method., Clinical Significance: The application of this technique allows, with inexpensive flashlights, to remove all the composite on the lingual surfaces during debonding, without damaging the tooth and saving time., (© 2020 Wiley Periodicals LLC.)

Introduction: The primary aim of this randomized in vitro study was to compare the effectiveness of carbide, fibreglass and polymer burs on resinous remnant removal after bracket debonding, by the evaluation of enamel surface roughness and morphology. The secondary objective was to compare the time dispended on the procedures., Methods: The buccal surfaces of 28 bovine incisors were analysed by a profilometer to initial roughness measurement (Ra-T1). Brackets were bonded with a light-cured resin and debonded with a debonding plier. The samples were randomly divided into four groups, according to the bur used (n=7): A-Tungsten carbide; B-Fibreglass; C-Polymer; D-Polymer with 75% ethanol pre-treatment. The second roughness measurements were made after resin removal (Ra-T2). Time for removal procedures was also recorded. The third measurements were made after polishing (Ra-T3). Scanning Electronic Microscopy was performed in two samples of each group: after resin removal and after polishing. Results of roughness and time measurements were statically analysed by analysis of variance with post-hoc Bonferroni., Results: After polishing, tungsten carbide (P=0.1555) and fibreglass burs provided final surface roughness statistically similar to the baseline condition (P=1.0000). Yet, polymer burs, associated (P<0.0001) or not to alcohol (P<0.0001), provided surface roughness significantly higher when compared to baseline values. Polymer burs were more time-consuming on resinous remnant removal than tungsten carbide and fibreglass burs (P<0.05)., Conclusion: Polymer burs were less effective and more time-consuming to remove the remaining resin than tungsten carbide and fibreglass burs. The polishing step created smoother surfaces regardless of the burs used for resin removal., (Copyright © 2020 CEO. Published by Elsevier Masson SAS. All rights reserved.)

Introduction: The objective of this study was to compare in vitro the resistance and type of failure in the debonding of lithium disilicate veneers with four different thicknesses using an erbium chromium yttrium-scandium gallium-garnet (Er,Cr:YSGG) laser. Methods: Sixty-eight bovine teeth were used to bond round lithium disilicate veneers with a 6-millimeter diameter and four different thicknesses: group 1 (0.4 mm), group 2 (0.8 mm), group 3 (1.2 mm) and group 4 (1.6 mm). Each sample was irradiated with an Er,Cr:YSGG laser with 4 W of power and a frequency of 50 Hz, during 60 seconds, scanning concentrically. The energy density per pulse or fluency applied was 5.33 J/cm2 for the four groups. The samples were subjected to a force in a universal testing machine and then observed under a microscope to determine the type of failure. Data were statistically analyzed with the non-parametric Kruskal-Wallis test. Results: The tendency in the results revealed that the thicker veneers showed more resistance to the debonding process. The debonding strength for group 3 was the highest (5.62 MPa), followed by group 4 (5.20 MPa), then group 2 (0.85 MPa) and finally group 1 (0.0 MPa). The most frequent type of failure was cohesive failure in cement (CC) for all groups, with 73.53% ( P ≤ 0.083). Conclusion: Er,Cr:YSGG laser irradiation influences the debonding of lithium disilicate veneers with different thicknesses: the smaller thickness showed the greater debonding. The thickness of veneers was not associated with the type of failure., (Copyright © 2020 J Lasers Med Sci.)

The purpose of this critical review is to list the sources of aerosol production during orthodontic standard procedure, analyze the constituent components of aerosol and their dependency on modes of grinding, the presence of water and type of bur, and suggest a method to minimize the quantity and detrimental characteristics of the particles comprising the solid matter of aerosol. Minimization of water-spray syringe utilization for rinsing is suggested on bonding related procedures, while temporal conditions as represented by seasonal epidemics should be considered for the decision of intervention scheme provided as a preprocedural mouth rinse, in an attempt to reduce the load of aerosolized pathogens. In normal conditions, chlorhexidine 0.2%, preferably under elevated temperature state should be prioritized for reducing bacterial counts. In the presence of oxidation vulnerable viruses within the community, substitute strategies might be represented by the use of povidone iodine 0.2%-1%, or hydrogen peroxide 1%. After debonding, extensive material grinding, as well as aligner related attachment clean-up, should involve the use of carbide tungsten burs under water cooling conditions for cutting efficiency enhancement, duration restriction of the procedure, as well as reduction of aerosolized nanoparticles. In this respect, selection strategies of malocclusions eligible for aligner treatment should be reconsidered and future perspectives may entail careful and more restricted utilization of attachment grips. For more limited clean-up procedures, such as grinding of minimal amounts of adhesive remnants, or individualized bracket debonding in the course of treatment, hand-instruments for remnant removal might well represent an effective strategy. Efforts to minimize the use of rotary instrumentation in orthodontic settings might also lead the way for future solutions. Measures of self-protection for the treatment team should never be neglected. Dressing gowns and facemasks with filter protection layers, appropriate ventilation and fresh air flow within the operating room comprise significant links to the overall picture of practice management. Risk management considerations should be constant, but also updated as new material applications come into play, while being grounded on the best available evidence., (Copyright © 2020. Published by Elsevier Inc.)

In order to evaluate the influence of 38% silver diamine fluoride (SDF) application on enamel and dentin bond stability of universal adhesives in self-etch mode, a 38% SDF and three universal adhesives were used in this study. Initial shear bond strength (ISBS), fatigue bond strength (FBS), and shear bond strength of survivors (SBSS) to enamel and dentin of universal adhesives in self-etch mode, with and without SDF application, were determined. SDF was applied to the polished enamel or dentin surface for 1 min, water-rinsed and air-dried for comparison with controls. The universal adhesives were applied to the prepared samples and composite resin was bonded using a mold-enclosed method. Enamel bond stability of universal adhesives with SDF (ISBS: 14.7-20.4 MPa; FBS: 5.5-7.4 MPa and SBSS: 14.4-21.5 MPa) was significantly weaker than those without SDF (ISBS: 28.0-29.2 MPa; FBS: 12.1-15.6 MPa and SBSS: 28.4-34.4 MPa). Dentin bond stability with SDF (ISBS: 14.8-20.9 MPa; FBS: 7.1-8.2 MPa and SBSS: 17.3-21.8 MPa) was also significantly weaker than without SDF (ISBS: 19.3-36.1 MPa; FBS: 11.0-13.7 MPa and SBSS: 22.2-34.6 MPa). The results suggest that SDF application on enamel and dentin reduces the bond stability of universal adhesives in self-etch mode., (© 2020 Eur J Oral Sci.)

Objectives: This study aims to investigate the effects of various mouthwashes on bacteremia development following a debonding process, which is performed after orthodontic treatment., Subjects and Methods: The study included patients who received fixed orthodontic treatment and were indicated for debonding. A total of 40 patients in four groups were selected for the study; no mouthwash (Group 1), mouthwash containing 0.12% chlorhexidine-gluconate (Group 2), mouthwash containing essential-oils (Group 3), and mouthwash containing 7.5% povidone-iodine (Group 4). Before (T 0 ) and following (T 1 ) the debonding procedure, blood samples were obtained from the patients. Then, the blood samples were placed in blood culture bottles to investigate bacterial growth., Results: Based on the results of the study, it was determined that the blood samples obtained at T 0 did not indicate any bacterial growth. Furthermore, it was observed that the blood samples obtained at T 1 included Streptococcus viridans, Streptococcus oralis, Streptococcus mutans, and Staphylococcus aereus growth, respectively, in 4 patients from Group 1 while Streptococcus salivarius growth was observed in 1 patient from Group 3 in addition to Streptococcus mitis growth in 1 patient from Group 4. No bacterial growth was observed in Group 2. While the results obtained between Group 1 and Group 2 were statistically significant, no statistically significant difference was observed between other groups., Conclusions: Finally, it was determined that the mouthwash 0.12% chlorhexidine-gluconate was statistically significant in comparison to the control group. It can be concluded that this mouthwash can be used to decrease bacterial density in oral flora before debonding procedures., Competing Interests: None

The aim of the present study was to evaluate how hydroabrasion performs during composite removal. A standardized amount of composite was bonded to 40 enamel surfaces of extracted third molars, then removed with either a tungsten carbide bur mounted on a micro-motor handpiece without irrigation, a tungsten carbide bur mounted on a micro-motor handpiece with irrigation, a tungsten carbide bur mounted on an air-rotor handpiece, or hydroabrasion. The four treatment methods were compared using the enamel-surface-index and the adhesive-remnant-index and performing a Kruskal-Wallis statistical test to detect differences between each method' scores. Hydroabrasion produced significantly less damage to the enamel surface compared to the other three methods. Hydroabrasion was the cleaning method that produced less damages to the enamel surface, at a cost of a less efficient composite removal than tungsten carbide burs on micro-motor handpiece.

Background: The study aimed to evaluate the permanence of resin and enamel remains on lingual brackets at the end of orthodontic treatment and after the debonding procedure. The evaluation of resin remnants on customized lingual brackets bases has never done before in other studies because they are curved, and traditional techniques are not applicable., Methods: The sample consisted of 100 lingual brackets (25 incisors, 25 canines, 25 premolars, 25 molars) scanned with a confocal laser microscope (OLS4000). We measured the brackets' surface and the area of resin remnants with the software of the microscope. Median and quartiles were presented to describe the data. ARI calculation was indirect for each tooth, measuring the resin remnants to the total surface of the bracket. The Kruskal-Wallis test and Fisher test were applied respectively to compare the percentages of remnants and the frequencies of the ARI between the four groups., Results: After the analyses, 13 brackets had no adhesive remnants (ARI 0), 29 brackets had less than 50% of resin remnants (ARI 1), 50 brackets had more than 50% of resin remnants (ARI 2), and 8 brackets had 100% of adhesive (ARI 3). Canines brackets presented the lower amount of resin followed by premolars, incisors, and molars., Conclusion: Lingual brackets showed a high frequency of ARI = 2. The median percentage of the bracket surface covered by resin was 41%. We observed a slight tendency of more resin remnants on molar brackets, due to half-pad configuration. The authors suggest paying attention during the debonding procedure of molar brackets since a stronger connection between the adhesive and the bracket mesh means a higher risk of enamel damage.

Objective: To evaluate the effect of a 445-nm diode laser on the shear bond strength (SBS) of metallic brackets before debonding. Background: Due to the new blue laser technology, very few studies are available in this context. Methods: Seventy metallic brackets (Discovery; Dentaurum, Ispringen, Germany) were bonded to the frontal enamel surfaces of 70 caries-free bovine incisors in a standardized way. Each sample was randomly assigned to the control or laser group, with 35 samples per group. The brackets in the laser group were irradiated with the diode laser (SIROLaser Blue ® ; Sirona, Bensheim, Germany) on three sides of the bracket bases for 5 s each (lateral-coronal-lateral, a total of 15 s) immediately before debonding. SBS values were evaluated for the control group and laser group. Micrographs of the enamel surface were taken with 10 × magnification to assess the adhesive remnant index (ARI) and the degree of enamel fractures after debonding. Results: There were no statistically significant differences in SBS in the laser group in comparison with the control group ( p  > 0.05). The distribution of ARI scores was also not statistically significantly different in the laser group in comparison with the control group ( p  > 0.05). Three enamel fractures occurred in the control group and one in the laser group after debonding. Conclusions: Irradiation of metallic brackets with the 445-nm diode laser before debonding does not significantly reduce the SBS values and does not influence the remaining amount of adhesive on the enamel surface. The risk of enamel fractures during debonding is therefore not clinically affected.

Introduction: A reliable adhesion between fixed devices and dental surfaces is a key factor for the clinical success of any orthodontic treatment. Adhesion preparation is associated with damages related to abrasive cleaning, enamel structure defacing caused by etching, enamel loss when removing resin remnants at orthodontic treatment finishing stage or when conditioning surface for adhesive failure and fractures at bracket removal., Aim: The objective of this study was to compare the shear bond strength of metallic brackets to enamel adhered with a novel non-damaging and remineralizing material for enamel versus the traditional 37% phosphoric acid etching., Material and Methods: 75 Premolars collected from 15- to 40-years old healthy donors requiring extraction were collected. The teeth were then randomly divided into three groups (n = 25). One group was used for the experimental new method (EX), the second for the conventional phosphoric acid etching (PA) method and the third group was left without any treatment (NT). The metallic brackets were fixed with Transbond® XT adhesive and composite resin polymerized for 40 s with a halogen photocuring lamp. The shear bond strength was quantified by means of a universal testing machine at 1 mm/min crosshead speed and a load cell of 1 kN., Statistical Analysis Used: Tests of normality, adjustment of the data to a root square, a one-way ANOVA and Tukey tests were performed., Results: Statistically significant differences between the NT (1.4 MPa), PA (32.1 MPa) and EX (9.7 MPa) groups were observed., Conclusions: The experimental material for conditioning human enamel induces calcium phosphates crystals on the enamel surface and improves the bond strength in comparison to the NT group., Competing Interests: The authors declare there are no potential conflicts of interest with the materials involved in the present investigation., (© 2019 The Authors.)

In this study, dentin bond fatigue resistance and interfacial science characteristics of universal adhesives through etch-and-rinse and self-etch modes were investigated. Resin composite was bonded to human dentin with four universal adhesives, namely, Adhese Universal, All-Bond Universal, G-Premio Bond, and Scotchbond Universal Adhesive. The initial bond strengths, bond fatigue strengths, and interfacial science characteristics of the universal adhesives with dentin through etch-and-rinse and self-etch modes were determined. Bond fatigue resistance (initial bond strength and bond fatigue strength) of universal adhesives in etch-and-rinse mode showed no significant difference in contrast to that in self-etch mode and was material-dependent regardless of the etching mode. Although phosphoric acid conditioning of dentin did not have a strong impact on the bond fatigue resistance, surface free energy and parameters of dentin were significantly decreased by etching and by application of universal adhesives regardless of etching mode. Changes in γ S and γ S h for when universal adhesive was applied to etched and ground dentin were significantly different depending on the adhesive. The results suggest that bonding performance of universal adhesives was effective in both etching modes; however, bonding mechanisms may be different for each.

Objectives: To compare a fluorescence-aided identification technique (FIT) with a conventional light source (CLS) for removing composite during debonding of brackets with respect to time needed, composite remnants, and tooth substance loss., Materials and Methods: Twelve maxillary models with 10 bovine teeth each were digitally surface-scanned and metal brackets were bonded on each tooth with Opal Seal and Opal Bond. Two operators: an experienced orthodontist (A) and an undergraduate student (B) received six models each and were asked to remove the composite remnants with a tungsten carbide bur and Sof-Lex discs by both a conventional light source (CLS group, n = 3), and fluorescent inducing light (FIT group, n = 3). The time taken was recorded, and a postoperative scan was digitally superimposed on the preoperative scan to quantify number of teeth with composite remnants and volume and thickness of enamel loss and composite remnants. Chi-square test and independent t- tests were performed to compare methods with a significance level of 5%., Results: Compared to CLS, both operators needed significantly less time when using the FIT method and degree of enamel loss, height, and volume of composite remnants and total remaining composite remnants were significantly reduced. By FIT, the volume of enamel loss was significantly reduced for operator A only. Operator B removed the same enamel volume with either method., Conclusions: Cleanup after orthodontic debonding with the FIT was superior regarding time needed and removal of composite remnants. Total enamel loss reduction was operator-dependent.

Background: To introduce an orthodontic bracket debonding device capable of measuring debonding force clinically by a novel sensor mechanism MATERIALS AND METHOD: A prototype orthodontic debonding device was constructed utilizing a lift-off debonding instrument (LODI) and force-sensitive resistor (FSR). For data interpretation, the force sensor was equipped with a microcontroller and C++ programming software running on a computer. Ninety-nine (99) 0.022-in. conventional metallic brackets were bonded to premolar teeth in vitro by a single clinician applying the same adhesive and bonding technique. For validation, the mean debonding force measured by the prototype debonding device (n = 30) and the universal testing machine (n = 30) was compared. Both intra- and inter-examiner reliability tests were done by holding and operating the device in a standardized manner. Following debonding by the prototype device, the bracket failure pattern was evaluated (n = 30) by adhesive remnant index (ARI) under the stereomicroscope at × 30 magnification. Statistical analysis included independent samples t test for validation and intraclass correlation coefficient (ICC) with a 95% confidence interval for both intra- and inter-examiner reliability., Results: Mean orthodontic bracket debonding force measured by the prototype device (9.36 ± 1.65 N) and the universal testing machine (10.43 ± 2.71 N) was not significantly different (p < 0.05). The prototype device exhibited excellent intra- [ICC (3, 1) = 0.942] and inter-examiner reliability [ICC (2, 1) = 0.921] and was able to debond brackets mostly at the bracket-adhesive interface., Limitation: Due to adjusting the position and mechanism of the force sensor, the device had to be held in a modified standardized position., Conclusion: A novel method of measuring in vivo orthodontic bracket debonding force has been introduced which proved to be validated, reliable, and safe in terms of enamel damage.

Background: Orthodontic bonding and debonding procedures involve risk of damaging the enamel surface and changing its original morphology. The rough surface inhibits proper cleaning, invites plaque deposition, bacterial retention, and stain formation thus dampening the esthetic appearance of the teeth. Restoring the enamel to its original morphology is a challenge. Researches on better adhesive removal methods which can effectively remove the residual resin and restore it best to its original form are continuing till date. No study has compared four contemporary finishing systems for their efficiency on a single platform., Aim: The objective of this study is to evaluate and compare enamel surface roughness after debonding using four different finishing and polishing systems., Material and Methods: Adhesive resin was removed from the buccal surface of 88 premolars after debonding with 4 groups. It included 22 teeth per group: group 1-One gloss system; group 2-Enhance finishing and polishing system; group 3-fiber reinforced stainbuster bur; and group 4-Soflex discs with wheels. Roughness was measured quantitatively and qualitatively with the help of surface roughness tester and scanning electron Microscope (SEM) respectively., Results: No significant difference was found in baseline roughness in four groups. Highest post-polishing roughness was observed in Soflex group (4.62 μm) followed by One gloss system (3.36 μm), Enhance system (3.17 μm), and stainbuster bur (1.99 μm) (p value < 0.01)., Conclusion: Stainbuster bur created the smoothest enamel surface that was close to the natural enamel followed by Enhance system, One gloss system, and Soflex disc and wheels.

Objectives: To assess the effectiveness and efficiency of ultraviolet (UV) illumination compared to conventional white light in the detection of fluorescent-tagged adhesive remnants during orthodontic debonding., Materials and Methods: Orthodontic brackets were bonded to extracted human premolars using one of two bonding resins having fluorescent properties (Pad Lock, Reliance Orthodontics, Itasca, Ill; Opal Bond MV, Opal Orthodontics, South Jordan, Utah; n = 40 each). The brackets were then debonded and, in each adhesive group, half the teeth had the remaining adhesive resin removed under illumination using the operatory light and the other half using a UV (395 nm) light emitting diode (LED) flashlight (n = 20/group). Time for teeth cleanup was recorded. Follow-up images were obtained under a dissecting microscope using UV illumination, and the surface area of adhesive remnants was calculated. Effectiveness of adhesive removal was also assessed using scanning electron microscopy imaging. Analysis of variance and Kruskal-Wallis tests were used to analyze time and adhesive remnants, respectively., Results: Assessment using the dissecting microscope found groups using UV light during adhesive removal had statistically significantly lower amounts of adhesive remnants than groups using white light ( P ≤ .01). Time for adhesive removal was significantly lower with Opal Bond MV adhesive using UV light when compared with the white light ( P ≤ .01). Assessment by scanning electron microscopy showed that thin remnants of adhesive (<2 μm) remained undetected by UV illumination., Conclusions: UV light is more effective and tends to be more efficient than white light in the detection of fluorescent adhesive during orthodontic debonding. Although there are limitations, the use of UV LED lighting is a practical tool that aids in adhesive detection.

The purpose of this study was to evaluate whether surface wetness would influence the bonding effectiveness of universal adhesives in etch-and-rinse mode. All-Bond Universal (AB), G-Premio Bond (GP), Prime & Bond Active (PB), and Scotchbond Universal Adhesive (SU) were evaluated. Initial bond strengths and bond-fatigue strengths of universal adhesives to both wet and dry enamel and dentin in etch-and-rinse mode were determined. Scanning electron microscopy observations of the adhesive interfaces were also conducted. The bond-fatigue durability of universal adhesive to enamel in etch-and-rinse mode was influenced by the surface wetness, unlike that to dentin. The bond fatigue durability of AB and GP to dentin in etch-and-rinse mode was different depending on the surface wetness, unlike that of PB and SU. The thicknesses of the adhesive or hybrid layer of resin-dentin interfaces were not influenced by the surface wetness, but the length of resin tags in the wet group was longer than in the dry group. Some universal adhesives with the addition of specific components and optimization of water content can achieve stable bonds regardless of surface wetness, but the surface wetness of dentin is still a significant factor for universal adhesive bonding in etch-and rinse mode, unlike that of enamel., (© 2018 Eur J Oral Sci.)

Objectives: This study aimed to assess the effect of erbium-doped yttrium aluminum garnet (Er:YAG) and erbium, chromium: yttrium, scandium, gallium, garnet (Er,Cr:YSGG) lasers on the shear bond strength (SBS) of ceramic brackets debonding from the surface of composite blocks., Materials and Methods: Thirty-six composite blocks were fabricated using Filtek Z250 light-cure composite. Block surfaces were etched with 37% phosphoric acid for 30 seconds and then rinsed with water for 20 seconds and dried. Maxillary right central incisor ceramic orthodontic brackets were bonded to the surfaces of composite blocks using Transbond XT adhesive and were cured for 40 seconds. Twelve samples were irradiated with Er:YAG laser, while 12 samples were irradiated with Er,Cr:YSGG laser, and the brackets were then debonded using a universal testing machine. Twelve samples served as controls (debonding using the universal testing machine without using a laser). The adhesive remnant index (ARI) score and bracket or composite cracks were evaluated under a stereomicroscope. One-way analysis of variance (ANOVA) was used for the comparison of the three groups. Kruskal-Wallis test was used to compare the ARI scores., Results: The mean SBS was 17.01±5.22 MPa with Er:YAG laser, 18.03±6.46 MPa with Er,Cr:YSGG laser, and 16.61±6.73 MPa in the control group; the difference of the three groups was not significant (P=0.835). The difference in the ARI scores and enamel and composite cracks was not significant either (P>0.05)., Conclusion: This study did not show any reduction in the bond strength of ceramic bracket to composite blocks after Er:YAG and Er,Cr:YSGG laser irradiation., Competing Interests: CONFLICT OF INTEREST STATEMENT None declared., (Copyright© Dental Research Center, Tehran University of Medical Sciences.)

Objectives: To investigate debonding of full crowns made of CAD/CAM composites, CAD/CAM technology was applied to manufacture standardized test abutments to increase the reproducibility of human teeth used in in vitro studies., Materials and Methods: A virtual test abutment and the corresponding virtual crown were designed and two STL data sets were generated. Sixty-four human third molars and CAD/CAM blocks were milled using a CNC machine. Crowns of four different composite blocks (Lava Ultimate (LU), Brilliant Crios (BC), Cerasmart (CS), Experimental (EX)) were adhesively bonded with their corresponding luting system (LU: Scotchbond Universal/RelyX Ultimate; BC: One Coat 7 Universal/DuoCem; CS: G-PremioBond/G-Cem LinkForce; EX: Experimental-Bond/Experimental-Luting-Cement). Half of the specimens were chemical-cured (CC) and the others were light-cured (LC). Afterwards, specimens were artificially aged in a chewing simulator (WL-tec, 1 million cycles, 50-500 N, 2 Hz, 37 °C). Finally, a dye penetration test was used to detect debonding. For inspection, the specimens were sliced, and penetration depth was measured with a digital microscope. Data were analyzed with the Mann-Whitney U test., Results: No cases of total debonding were observed after cyclic loading. However, the LC specimens showed a significantly lower amount of leakage than the CC ones (p < 0.05). Furthermore, the CC specimens exhibited broad scattering. Only the LC-EX blocks showed no debonding. The CC-CS blocks showed the highest leakage and scattering of all tested specimens., Conclusions: Natural human teeth can be manufactured by CAD/CAM technology in highly standardized test abutments for in vitro testing. For CAD/CAM composites, light curing should be performed., Clinical Relevance: The success of a restoration depends on the long-term sealing ability of the luting materials, which avoids debonding along with microleakage. For CAD/CAM composites, separate light curing of the adhesive and luting composite is highly recommended.

Background: Medical digital imaging is the basis of effective medical diagnosis and is now in the mainstream of a dynamically developing branch of science. Optical coherence tomography (OCT) enables real-time in situ imaging of tissues without the need for biopsy, histological procedures or X-rays., Objectives: The aim of the study was to evaluate the application of OCT in orthodontic diagnostics and clinical practice by assessing the thickness of the enamel before and after orthodontic treatment., Material and Methods: A hundred and eighty teeth in this in vitro study were divided into 3 groups of 60 teeth each. In each group (Group 1 - metal brackets, Group 2 - ceramic brackets and Group 3 - composite brackets), the orthodontic brackets were attached to the enamel using the 5th-generation adhesive system. The image of the enamel tissue was captured with a 3D-OCT camera before installing orthodontic brackets and after debonding and mechanical processing. The obtained OCT scans were subjected to expert IT analysis. For the statistical analysis, the Shapiro-Wilk test, the median test, the Mann-Whitney U test, Friedman 2-way analysis of variance (ANOVA), Wilcoxon matched pairs signed ranks test, the χ2 test of independence with Yates's correction, and Fisher's exact test were used. Maxwell's general principle was followed when using this type of test. The level of significance was set at p = 0.05., Results: The thickness of the enamel varied least when metal brackets were used. The changes in enamel thickness in the composite and ceramic bracket groups were not statistically significant., Conclusions: Optical coherence tomography is an effective diagnostic tool to evaluate the thickness of the enamel tissue before and after orthodontic treatment. Changes in the enamel layer thickness after orthodontic treatment are determined by the type of material which the orthodontic bracket is made of.