Debonding Of Orthodontic Brackets Research Articles

Micron-scale human enamel layer characterization after orthodontic bracket debonding by intensity-based layer segmentation in optical coherence tomography images

In clinical orthodontic practice, fixed brackets are widely used for tooth movement and adjustments. Although years of research and development have improved the workability of fixed orthodontic brackets, there are still controversies regarding its plausible destructive influence on the enamel surface of tooth. This, in turn, makes the quantitative assessment of the enamel surface after specific orthodontic treatment procedures important in order to opt for the most effective treatment procedure. Through this study, we show the practical applicability of optical coherence tomography (OCT) as a non-ionizing and nondestructive assessment tool for measuring enamel loss after each step of orthodontic bracket bonding. Two-dimensional and volumetric OCT images are used for the evaluation of the tooth enamel. From the depth intensity profile analysis of cross-sectional OCT images, the changes in the individual internal layer thickness are calculated. A software algorithm was developed to evaluate the structural connectivity in the enamel for analyzing enamel loss on the tooth surface and for detecting enamel abrasion. An intensity-based layer segmentation algorithm is also developed to analyze and evaluate enamel wear in the tooth after each step. Using the proposed algorithms, the total enamel present after each treatment procedure was measured and tabulated for analysis.

The Effect of Erbium-Doped Yttrium Aluminum Garnet Laser in Debonding of Orthodontic Brackets: A Systematic Review of the Literature.

Objective: The purpose of this review is to systematically assess the existing literature and summarize the evidence regarding the effect of erbium-doped yttrium aluminum garnet (Er:YAG) laser on enamel surface roughness and pulp health compared with the conventional orthodontic debonding techniques. Materials and methods: Following the preferred reporting items for systematic reviews (Preferred Reporting Items for Systematic Reviews and Meta-analyses) statement, the electronic database, PubMed, Scopus, Web of Science, Google scholar, and Saudi Digital Library were searched for relevant published records. Data were collected following specific keywords: "debonding" "Er:YAG laser" etc. In vitro studies, and clinical randomized- and nonrandomized-controlled studies limited to the English language and published in peer-reviewed journals were included. Results: A total of 564 articles were identified as relevant to the topic. Duplicates were excluded resulting in 382 articles, out of which 374 articles were discarded upon screening titles and abstracts. The remaining eight articles were read to their entirety and included in the current qualitative review after fulfilling the eligibility criteria. In all the included studies, a total of 480 sound posterior teeth were used to evaluate the effect of Er:YAG laser on debonding of orthodontic brackets from the enamel surface. Conclusions: Er:YAG laser debonding has demonstrated a reduced risk of enamel damage (fracture or cracks) but resulted in increased enamel surface roughness and was time-consuming for adhesive removal procedures compared with the conventional debonding methods. Further, within the applied laser settings, Er:YAG lasers have found to exhibit low thermal exhaustion in relation to the pulp. The laser source with a wavelength of 2940 nm has been used with different setting ranges (power of 2.5-5 W, energy 125-600 mJ, frequency 4-30 Hz, and pulse duration 50-350 μsec) for debonding of orthodontic brackets.

Comparison of Orthodontic Bracket Debonding Force and Bracket Failure Pattern on Different Teeth In Vivo by a Prototype Debonding Device.

Objective To compare the orthodontic bracket debonding force and assess the bracket failure pattern clinically between different teeth by a validated prototype debonding device. Materials and Method. Thirteen (13) patients at the end of comprehensive fixed orthodontic treatment, awaiting for bracket removal, were selected from the list. A total of 260 brackets from the central incisor to the second premolar in both jaws were debonded by a single clinician using a validated prototype debonding device equipped with a force sensitive resistor (FSR). Mean bracket debonding forces were specified to ten (10) groups of teeth. Following debonding, Intraoral microphotographs of the teeth were taken by the same clinician to assess the bracket failure pattern using a 4-point scale of adhesive remnant index (ARI). Statistical analysis included one-way ANOVA with post hoc Tukey HSD and independent sample t-test to compare in vivo bracket debonding force, Cohen's kappa (κ), and a nonparametric Kruskal-Wallis test for the reliability and the assessment of ARI scoring. Results A significant difference (p < 0.001) of mean debonding force was found between different types of teeth in vivo. Clinically, ARI scores were not significantly different (p = 0.921) between different groups, but overall higher scores were predominant. Conclusion Bracket debonding force should be measured on the same tooth from the same arch as the significant difference of mean debonding force exists between similar teeth of the upper and lower arches. The insignificant bracket failure pattern with higher ARI scores confirms less enamel damage irrespective of tooth types.

Comparative Evaluation of Different Numerical Pain Scales Used for Pain Estimation during Debonding of Orthodontic Brackets.

Introduction Patients experience various levels of discomfort during orthodontic treatment, i.e., after placement of separators, orthodontic implant placement, and archwire placement and during debonding. Various pain control methods have been developed to relive pain during debonding, i.e., finger pressure (FP), elastomeric wafer (EW), and stress relief (SR). Aim To analyse various pain scales commonly used to determine the effect of different pain control methods during debonding of orthodontic brackets. Study Design. A comparative cross-sectional study performed on a sample of 60 patients (n = 60) including 14 males and 46 females who were ready for debonding and who were divided into three groups, i.e., finger pressure (FP), elastomeric wafer (EW), and stress relief (SR). Materials and Methods A 100 mm Visual Analog Scale (VAS) was used to record the pain intensity for each tooth. Another scale known as Pain Catastrophizing Scale (PCS) was used to evaluate the patient's general attitude towards pain perception. The armamentarium and operator were kept same for all the patients. Statistical analysis used was the Kruskal–Wallis test, used for intergroup and intragroup comparison of pain scores. Results Lowest total pain score was recorded in the FP group (P=0.043) on intergroup comparison, while on intragroup comparison, higher pain scores were recorded in lower anterior region (P=0.02) in all three groups. There was no significant difference between the pain scores reported by the male and female subjects. Conclusion FP is an effective method of pain control. And teeth in the anterior region of lower and upper arches are more sensitive to pain. In terms of cognitive-affective constructs, although the VAS has been widely used in previous studies, the PCS has been detailed to show the most reliable association with physical discomfort and emotional distress.

Debonding of Orthodontic Ceramic brackets: A comprehensive review of the literature – Part 1

The purpose of this 2 part literature review is to evaluate various debonding techniques for orthodontic ceramic bracket removal and their clinical applications.In part 1, and studies on mechanical and ultrasonic debonding techniques have been reviewed. Mechanical debonding (use of diamond burs, special pliers) is most widely applicable in clinical practice. Use of recommended pliers by manufacturers is key to minimize bracket failure modes as these pliers are designed specifically for the brackets. Ultrasonic debonding is advantageous in minimizing bracket failure but requires greater time to debond ceramic brackets than mechanical debonding and it may be uncomfortable to the patient due to longer duration of use. Studies on electrothermal and Laser debonding have been reviewed in part 2 of the literature review.

Debonding of Orthodontic Ceramic brackets: A comprehensive review of the literature – Part 2

The purpose of this 2 part review is to evaluate various debonding techniques for orthodontic ceramic bracket removal and their clinical applications.In this part 2 of the literature review, and studies on electrothermal debonding and Laser debonding techniques have been reviewed. Electrothermal debonding is a physiologically acceptable alternative to mechanical debonding. It requires minimal force following thermal softening of adhesive material and produces minimal changes to enamel surfaces compared to conventional methods. Minimal effects on enamel and intrapulpal temperature changes are noted with ytterbium fiber laser, diode laser and Tm:YAP laser. Different parameters are possible with CO laser, Nd:YAG laser and Er:YAG laser that may need further research before considering them in clinical practice.

Effects of polishing with paste containing surface pre-reacted glass-ionomer fillers on enamel remineralization after orthodontic bracket debonding.

Surface pre-reacted glass-ionomer (S-PRG) technology allows for the release of multiple ions. This study was performed to investigate the remineralization of etched enamel after removal of the bracket using a novel paste containing S-PRG filler. Surfaces of polished enamel were etched with phosphoric acid and then subdivided into two regions. Bracket bonding resin was thinly applied to one region. After 24-hr immersion in artificial saliva, the bonding resin on the enamel surfaces was removed by grinding with tungsten carbide bur at low-speed, followed by polishing with one of four different polishing systems: (a) nonfluoridated paste (NF); (b) fluoridated paste (F); (c) S-PRG filler-containing paste (S-PRG); or (d) nonfluoridated plus S-PRG filler-containing paste (NF + S-PRG) (n = 15). The polished specimens were then immersed in an artificial saliva solution for 7 days. Nanoindentation testing of enamel surfaces was performed and their mechanical properties were compared. Representative specimens were examined with scanning electron microscope. In all specimens, the mechanical properties of the enamel surfaces were markedly degraded by acid etching. However, the mechanical properties of both regions (etched and resin-infiltrated enamels) showed recovery after polishing and 7-day immersion. Polishing with NF + S-PRG paste led to significant recovery of mechanical properties compared to polishing with NF or S-PRG paste alone, and remineralization was equivalent to that seen with F paste. Porous etched enamel surfaces were filled with a remineralization layer after each polishing procedure and 7-day immersion in all polishing groups. Polishing using NF + S-PRG paste can facilitate enamel remineralization after bracket removal.

Spectrophotometric analysis of dental bleaching after bonding and debonding of orthodontic brackets

IntroductionThe aim of this study was to evaluate the bleaching effect after aging simulation in teeth submitted to bonding and debonding of orthodontic brackets. Materials and methodsFor this study, 90 human premolars were selected, and randomly divided into 6 groups: control, bleaching, and other 4 groups submitted to bleaching after bonding and debonding brackets using different methods. Color measurement of sample through the CIE L*a*b* system was performed in three moments: T1 – after brackets debonding, T2 – after staining cycling, and T3 – after bleaching. For evaluation of results among the components L*, a* and b*, the two criteria analysis of variance and the multiple comparison Tukey test (p < 0.05) were used. ResultsStatistically significant difference was observed among the groups submitted to brackets bonding and debonding through self-conditioning adhesive system and tungsten drill, also the control and bleaching groups between the moments T1 e T2. ConclusionBonding and debonding brackets methods tested in this study showed influence on the sample color change, and after the tooth bleaching process, only the group without brackets previous bonding achieved the color value presented before the staining and aging of samples in the brackets absence.

Thermal effect of Er:YAG and Er,Cr:YSGG used for debonding ceramic and metal orthodontic brackets: An experimental analysis.

In orthodontics, erbium (Er:YAG) lasers can be used for bracket debonding. To assess the changes in temperature of pulp and enamel during laser debonding of brackets. A total of 13 brackets (n = 13; 2 metal and 11 ceramic brackets) were bonded to 13 caries-free premolars extracted for orthodontic reasons. Brackets were irradiated with 2 lasers. Laser No. 1 was an erbium-chromium (Er,Cr:YSGG) laser (Waterlase Express; Biolase, Irvine, USA) with a wavelength of 2,780 nm at a power of 2.78-2.85 W, energy of 185-190 mJ, fluence of 10 ns, frequency of 25 Hz, pulse duration of 300 μs, tip diameter of 0.6 mm, air/fluid cooling of 3.5 mL/s, and time of irradiation of 5-25 s. Laser No. 2 was an Er:YAG laser (LiteTouch; Light Instruments Ltd., Yokneam, Israel) with a wavelength of 2,940 nm at a power of 4 W, energy of 200 mJ, fluence of 10 ns, frequency of 20 Hz, pulse duration of 300 μs, tip diameter of 0.8 mm, air/fluid cooling of 3.5 mL/s, and time of irradiation of 5-15 s. Two thermographic cameras (FLIR Zenmuse XT and FLIR P65; FLIR Systems, Wilsonville, USA) and type K thermocouple (Zhangzhou Weihua Electronic Co., Fujian, China) were used for precise temperature measurement on the surface of the teeth and inside them. When laser No. 1 was in use, the mean difference between the inner and outer temperature of the examined teeth (1.4°C) was higher than when the laser No. 2 was in use (0.6°C) (p = 0.0974). The study found that the temperature inside the tooth did not increase, and it even decreased during treatment with Er:YAG laser using water cooling, provided that appropriate proportion of water and air was used. For laser No. 1, confidence interval (CI) was between 0.7 and 2.2 and for laser No. 2 it was between 0.500 and 1.23. Only experiment for ceramic brackets was described. These findings confirm that the use of Er:YAG family lasers for orthodontic bracket debonding in an in vitro study is safe and effective.

Evaluation of Enamel Roughness in Vitro After Orthodontic Bracket Debonding Using Different Methods of Residual Adhesive Removal.

The aim of the present study was to compare different techniques for resin remnant removal (RRR) after orthodontic bracket debonding and to evaluate alterations on the dental enamel caused by these methods. The null hypothesis tested was that there is no difference between RRR techniques in relationship the changes caused on the dental enamel. A total of 75 bovine mandibular permanent incisors were used in the study. Brackets were bonded and debonded in each tooth in two experimental regions. Five RRR techniques were used in the experimental groups (n=15): Group 1-diamond bur (6-bladed), Group 2-diamond bur (12-bladed), Group 3-diamond bur (30-bladed), Group 4-aluminum oxide sandblasting (AOS), and Group 5-Er:YAG laser. Enamel surface was evaluated using profilometry, and surface roughness analysis was performed at three time intervals: before bracket bonding, after RRR techniques, and after final polishing. Qualitative analyses of the enamel surfaces were performed using scanning electron microscopy. Multiblade burs showed the best results, and the 30-bladed bur created a less irregular enamel surface. AOS caused greater enamel wear, and Er:YAG laser caused more surface irregularity. The null hypothesis was rejected. The multiblade burs were the least harmful than the other techniques. Enamel surface roughness after using the 30-blade bur was similar to the original enamel. These results indicate that the type of bur tested (30-bladed) can be indicated to remove resin remnants after bracket debonding.

Comparison of the enamel surface characteristics after orthodontic debonding with and without microabrasion: An in vitro study

Aim: To visually compare, using microscope, two different techniques for removing adhesive remnants after orthodontic bracket debonding. Methods: Twenty healthy third molars were used. One molar did not undergo any procedures and served as a control. After bracket bonding and immersion of the teeth in saline solution for 12 days, the attachments were debonded. One of the molars was not stripped of the attachments, while the others (n=18) were randomly divided into two groups according to the adhesive removal technique: Group 1, use of a high-speed 18-blade bur and a fine-grain sandpaper disc; and Group 2, use of a high-speed 18-blade bur, a fine-grain sandpaper disc, and enamel microabrasion. Tooth fragments were collected for inspection under a field emission scanning electron microscope for a qualitative analysis of the adhesive remnants. Results: A substantial amount of adhesive residue remained on the enamel surface of the molars in Group 1. The procedures performed in Group 2 were more effective in removing the adhesive remnants but resulted in greater enamel wear and ledge formation. Conclusion: The combined use of a multiblade bur and the microabrasion technique was the most effective method of removing adhesive remnants and returning the enamel to its pre-treatment appearance.

Comparative effect of three polishing systems on porcelain surface roughness after orthodontic bracket debonding and composite resin removal: An atomic force microscopy

Purpose: Porcelain polishing after orthodontic bracket debonding and resin removal is imperative to eliminate surface roughness and minimize the risk of plaque accumulation, periodontal disease, and porcelain discoloration. This study aimed to assess the effect of three polishing systems on porcelain surface roughness after orthodontic bracket debonding. Materials and Methods: Thirty porcelain blocks were divided into three groups. Surface roughness of the samples was first measured using atomic force microscopy (AFM) and recorded as baseline. Orthodontic brackets were bonded to blocks by composite resin. After bracket debonding, resin remnants were removed by tungsten carbide bur. The blocks were then polished with Sof-Lex discs, Meisinger, and Jota porcelain polishing kit. Surface roughness was measured again using AFM. The Shapiro–Wilk test, one-way ANOVA, and Tukey’s post hoc test were used for data analysis through SPSS version 18.0. Level of significance was set at 5%. Results: The mean change in surface roughness after polishing with Jota kit (56.6 nm) was significantly greater than that compared to Sof-Lex discs (10.7 nm) (P = 0.003) and Meisinger kit (26.6 nm) (P = 0.024). The mean change in surface roughness was not significantly different between Sof-Lex and Meisinger groups. Surface roughness significantly increased in all three groups (P &lt; 0.05). Conclusion: Meisinger polishing kit and Sof-Lex discs were not significantly different in terms of the resultant surface roughness. Thus, the conventional use of Sof-Lex discs seems to be more cost-effective due to their lower cost.

Validation and reliability of a prototype orthodontic bracket debonding device equipped with force-sensitive resistor (FSR): a novel method of measuring orthodontic bracket debonding force in vivo

BackgroundTo introduce an orthodontic bracket debonding device capable of measuring debonding force clinically by a novel sensor mechanismMaterials and methodA 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.ResultsMean 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.LimitationDue to adjusting the position and mechanism of the force sensor, the device had to be held in a modified standardized position.ConclusionA 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.

Effect of two polishing systems on color and surface roughness of feldspathic porcelain following orthodontic bracket debonding and composite resin removal

Objectives Orthodontic bracket removal from a porcelain crown can roughen the surface and lead to plaque accumulation, discoloration, and esthetic problems. Porcelain polishing after debonding is one strategy to decrease such consequences. This study aimed to compare the efficacy of two polishing systems (Sof-Lex discs and Meisinger polishing system) for correction of surface roughness and discoloration of porcelain after orthodontic bracket debonding. Materials and Methods Twenty porcelain blocks were evaluated in two groups of 10. First, the baseline surface roughness and color parameters of the samples were measured using atomic force microscopy and spectrophotometry, respectively. After bracket bonding, a fine cutter was used for bracket debonding, and resin remnants were removed by a tungsten carbide bur and low-speed handpiece. Samples were then polished using Sof-Lex discs (group 1) and Meisinger porcelain polishing kit (group 2). Surface roughness and color parameters were measured again. Data were analyzed using SPSS 18 through the Shapiro–Wilk test, Student’s t-test, and paired t-test at 5% level of significance. Results Porcelain color change (ΔE) was significantly greater in the Meisinger system than Sof-Lex (P &lt; 0.001). The Rq, Ra, and Rt surface roughness parameters significantly increased in both the groups after the intervention compared to baseline (P &lt; 0.05), but the two groups were not significantly different in this respect after the polishing procedures (P &gt; 0.05). Conclusion The porcelain color after polishing with Sof-Lex discs was closer to the baseline. Furthermore, the two systems were not significantly different regarding surface roughness. However, Sof-Lex discs may be recommended due to lower cost.

Evaluation of a Fluorescence-aided Identification Technique (FIT) to assist clean-up after orthodontic bracket debonding

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. 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%. 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. Cleanup after orthodontic debonding with the FIT was superior regarding time needed and removal of composite remnants. Total enamel loss reduction was operator-dependent.

Feasibility of Different Methods after Debonding of Orthodontic Brackets: An In Vivo Study

Feasibility of Different Methods after Debonding of Orthodontic Brackets: An In Vivo Study

Recovery of Clinical Periodontal Parameters After Orthodontic Appliance Removal: A Prospective Study

Objectives Considering the changes in periodontal parameters after orthodontic treatment and lack of adequate evidence on the return of these parameters to normal, the aim of this study was to evaluate the time needed for recovery of periodontal parameters to normal after debonding. Methods In this prospective study, 24 patients (21 females and 3 males) with a mean age of 18.86 ± 4.64 years were included, who were in the final stage of their orthodontic treatment and ready for debonding of orthodontic brackets. The most important inclusion criteria were: No history of periodontal problems, no extensive restorations and caries, no smoking, no systemic disorders and no calculus. In each session, the patients were given oral health instructions and then probing depth (PD), plaque index (PI), gingival index (GI) and bleeding on probing (BOP) of the first molars and central incisors of each quadrant were evaluated at the time of debonding (T1), and one (T2), two (T3) and three (T4) months later; in patients who did not return to normal status (GI ≤ 0.5, negative BOP, PD ≤ 3 mm) after 3 months, the measurements were repeated in subsequent months (up to 6 months). ANOVA followed by pairwise Tukey comparisons were used for determining differences in PD, GI, BOP and PI between the time intervals. Results In general, all the parameters were decreased from T1 to T4. Furthermore, comparisons between different intervals using post hoc Tukey test showed that decreases in PD of the buccal surface and proximal surface in comparison to debonding time were significant during the first and second months, respectively (P < 0.05). Interpretation of statistical data showed a significant reduction in GI after two months. BOP became negative and significantly different after one month in half of the teeth and two months in the other teeth. PI generally decreased from T1 to T4. Conclusions Based on the results of this study, periodontal parameters returned to normal one to two months after debonding.

Orthodontic Bracket Bonding Using Self-adhesive Cement to Facilitate Bracket Debonding.

To evaluate shear bond strength (SBS), adhesive remnant index (ARI), and orthodontic bracket base after debonding of orthodontic brackets bonded using two different adhesives. Ninety sound human premolars were divided into three groups of n = 30. 1. Transbond, where brackets were bonded with Transbond XT (3M Unitek); 2. Multilink, where brackets were bonded with Multilink Speed (Ivoclar Vivadent); 3. Multilink+etch, where brackets were bonded using Multilink Speed after etching enamel. ARI scores were obtained using a stereomicroscope. SEM was used to evaluate the treated enamel surfaces and the base of the brackets. One-way ANOVA was performed to statistically analyze SBS. The Kruskal-Wallis test was conducted to investigate ARI scores, followed by multiple comparison tests (p < 0.05). SBS was significantly lower in the Multilink group compared to the other groups (p < 0.05). SEM evaluation revealed minimum penetration of resin tags within the enamel and that most of the resin was attached to the base of the brackets in the Multilink group compared to the other two groups (p < 0.05). Application of Multilink Speed on nonetched enamel provides acceptable SBS of orthodontic brackets bonded to enamel with minimum penetration of resin tags into enamel and less residual resin on tooth surfaces.

Effects of debonding of orthodontic brackets on topography and surface roughness of composite restorations

To increase bond strength of brackets bonded to composite restorations, underlying composite restorations are usually roughened. This and subsequent bracket debonding might deteriorate smoothness of composite restoration, leading to clinical and aesthetic problems. Since this was not assessed before, this study was conducted. Seventy intact human premolars were collected and filled with composite restorations. They were randomly divided into 3 groups: control (n=10), surface treatments before bracket bonding (bur, sandblasting, overall n=40), and surface roughening without bracket bonding (bur, sandblasting, overall n=20). The 40 specimens with bracket bonding steps were divided into two subgroups of with and without polishing after debonding of brackets (each n=10). After aging the composites in two steps and treating surfaces according to abovementioned protocols, their surface topographies were evaluated under stereomicroscopy (80×), scanning electron microscopy (using Zachrisson-Arthun index, at 500× and 1000× zooms), and by profilometry. Profilometry parameters and Zachrisson-Arthun index were statistically compared among different groups (α=0.05, 0.005). According to Kruskal-Wallis test, all profilometry parameters or the Zachrisson and Arthun index were significantly different between groups involving bracket debonding and control (P≤0.001). Three-way ANOVA indicated that bracket debonding, polishing after debonding, and surface treatments before bracket bonding had a significant effect on Ra and Rz (P≤0.05). Tukey post hoc test showed that bur and sandblasting methods were not significantly different (P>0.05). Bur-roughening or sandblasting of composite surface before bonding brackets can increase surface roughness, while polishing can reduce it back to control levels.

Analysis of enamel surface roughness after different adhesive removal techniques for orthodontic bracket debonding

The objectives of this study were to explore traditional resin removal procedures in the debonding process and evaluate the Er:YAG laser as a plausible option. Sixty premolar teeth were bonded with brackets. Then, brackets were removed and five adhesive clean-up methods were tested against control teeth: (a) Er:YAG laser at 200 mJ and 20 Hz; (b) Er:YAG laser at 305 mJ and 10 Hz; (c) 20-fluted flame-shaped tungsten carbide bur at high-speed; (d) #8-fluted round tungsten carbide bur at low-speed; and (e) #5 round end tapered fine diamond bur at high speed. Quantitative measurements including average (Avg) profile height, total indicator run-out (TIR), arithmetic average roughness (Ra), and time were made using profilometry. Qualitative evaluation of tooth surfaces was done using SEM. The two laser settings produced a statistically higher TIR, Ra, and time compared to the controls (P < 0.001). There was no statistical difference between the three bur techniques in regards to surface texture or time. Qualitatively, the 20-fluted carbide bur left the smoothest surface. The Er:YAG laser at the tested settings would not be appropriate for adhesive removal. The interaction of the Er:YAG wavelength under these conditions was not comparable to the 20-fluted flame-shaped tungsten carbide bur at high speed for orthodontic adhesive removal leaving a smoother enamel surface.