Search Results (47)

This in vitro study compared the bond strength performance and adhesive remnant characteristics of two metallic orthodontic pre-coated bracket systems: APC™ Plus and APC™ Flash Free. Forty extracted human premolars were randomly allocated to two groups (n = 20). Following enamel etching with 37% phosphoric acid, brackets were bonded according to the manufacturers’ recommendations. Bond strength testing was performed using a custom-made apparatus in which failure was induced through a progressively increasing load. Because the experimental setup generated a combined loading configuration involving shear, tensile, and bending components, the measured values should be interpreted as comparative bond strength measurements rather than absolute shear bond strength values. Adhesive Remnant Index (ARI) scores were recorded after debonding to evaluate failure patterns. Median bond strength values were 17.75 MPa (IQR: 13.53–21.98) for APC™ Plus and 14.28 MPa (IQR: 9.81–18.74) for APC™ Flash Free. No statistically significant difference was found between groups (Mann–Whitney U test, p = 0.102). In contrast, ARI score distributions differed significantly (Fisher’s exact test, p = 0.001). APC™ Plus brackets predominantly exhibited ARI scores of 2–3, whereas APC™ Flash Free brackets mainly demonstrated ARI scores of 1–2, indicating less adhesive remaining on the enamel surface after debonding. Three enamel fractures were observed in the APC™ Plus group, while none occurred in the APC™ Flash Free group; however, no statistically significant association between bracket type and enamel fracture was identified. Within the limitations of this in vitro study, both bracket systems demonstrated comparable bond strength performance under the experimental conditions investigated. APC™ Flash Free brackets were associated with reduced adhesive remnants on enamel, which may facilitate post-debonding cleanup. Further studies using standardized testing methods and prospective clinical investigations are required to confirm these findings and determine their clinical relevance. Full article

Background: Pain during orthodontic debonding is a common clinical concern. Although previous studies have mainly focused on mechanical approaches to reduce discomfort, the influence of emotional characteristics of patients on pain perception remains insufficiently explored. In this study, we aimed to evaluate the association between pain perception, emotional affect, and anxiety during orthodontic bracket removal using different clinical protocols. Methods: A prospective observational comparative study was conducted at Rey Juan Carlos University (Madrid, Spain). A total of 140 orthodontic patients underwent bracket removal according to four routine clinical protocols determined by clinical scheduling: ligated with interocclusal cotton rolls (used for tooth stabilization), non-ligated with cotton rolls, ligated without cotton rolls, and non-ligated without cotton rolls. Pain intensity was assessed using a Visual Analog Scale (VAS) immediately before (T0) and after (T1) bracket removal. Baseline pain (T0) was recorded to control for pre-existing discomfort. Anxiety and emotional affect were measured using the State–Trait Anxiety Inventory (STAI) and the Positive and Negative Affect Schedule (PANAS), respectively. Statistical analyses included ANOVA, factorial ANCOVA adjusted for baseline pain, and multivariable regression models. Results: No significant baseline differences were observed among groups. The highest post-debonding pain scores were found in the group without cotton rolls and without ligatures. ANCOVA revealed a significant main effect of cotton roll use, with lower adjusted pain scores in patients treated with cotton rolls, whereas ligation showed no statistically significant independent effect. In multivariable regression analyses, baseline pain, age, and negative affect were independently associated with higher post-debonding pain. Conclusions: Within the limitations of a non-randomized design, cotton roll use was associated with lower post-debonding pain, whereas ligation appeared to have a limited influence. Patient-related factors—particularly negative affect, age, and baseline pain—were also associated with pain perception, supporting a biopsychosocial perspective. These findings should be interpreted as exploratory evidence rather than causal effects. Full article

Background: Durable adhesion between orthodontic brackets and enamel is essential for successful fixed orthodontic therapy. Despite simplified adhesive systems being available, conventional etch-and-rinse adhesives remain widely used due to their reliable enamel bonding. Methods: This in vitro study evaluated the bonding performance of three orthodontic adhesive strategies in combination with Transbond XT composite resin for metal bracket fixation. Thirty extracted human premolars were randomly allocated to three groups according to the adhesive system applied: OptiBond Solo Plus (etch-and-rinse method), SafeBond Universal DC (selective enamel etching method) and Transbond XT primer (control method). Shear adhesion resistance, maximum force and breakout force were measured and statistically analysed. Results: No statistically significant differences were observed between the OptiBond and SafeBond groups for any of the evaluated mechanical parameters (p > 0.05), although the OptiBond group exhibited higher mean values. The Transbond XT primer group showed significantly lower adhesion resistance and debonding forces than both of the other groups (p < 0.05). SafeBond demonstrated lower variability of results compared with OptiBond. Conclusions: When used with Transbond XT composite resin, both OptiBond Solo Plus and SafeBond Universal DC provided comparable mechanical performance for metal bracket bonding. While OptiBond yielded higher mean bond strength values, SafeBond exhibited more consistent behaviour. The Transbond XT primer alone resulted in inferior bonding performance. Full article

Background/Objectives: The performance of the adhesive system used for bonding fundamentally influences the success of fixed orthodontic treatment. To withstand masticatory forces and prevent bracket debonding, it is critical to achieve optimal shear bond strength (SBS), improving treatment time. The aim of this study was to compare the shear bond strength and adhesive remnant index (ARI) of orthodontic brackets bonded using LED light-curing units with intensities of 3200 mW/cm² at two different exposure times, evaluated after 24 h and 14 days. Methods: Eighty extracted permanent premolars were randomly divided into four experimental groups. Brackets were bonded using Transbond XT adhesive and cured with a VALO™ Ortho Cordless unit (3200 mW/cm²) for 3 or 6 s. SBS was measured using a universal testing machine, and the ARI was assessed under a stereomicroscope at 40× magnification. Results: Increased light intensity and longer curing time significantly improved SBS values. The highest bond strengths were observed in groups cured with 3200 mW/cm² for 6 s, after 14 days. ARI scores showed that longer curing reduced adhesive remnants on the enamel. Statistical analysis confirmed significant differences among groups. Conclusions: Therefore, clinicians may achieve better bonding performance and easier enamel clean-up by using high-intensity lights with adequate curing duration. Full article

In fixed orthodontic treatment, brackets are orthodontic attachments bonded to the tooth enamel, and their placement and removal may affect the underlying enamel surface. Enamel degradation is a critical factor for oral health, as it reduces the mechanical strength of teeth and increases susceptibility to caries and erosion. Accurate diagnosis of enamel changes is therefore essential for the evaluation of preventive and restorative treatments. In this study, enamel degradation was investigated via two integrated methods: energy-dispersive X-ray spectroscopy (EDS) and surface roughness measurement. The experimental protocol was performed in three stages: before bracket bonding, after bracket removal, and after applying a remineralization treatment. The experimental design included a repeated-measures structure, with stage (baseline, post-debonding, post-remineralization) as the within-tooth factor and bracket type (sapphire vs. metallic) as the between-tooth factor. Given the violation of the variance homogeneity assumption, group comparisons were ultimately performed using Welch ANOVA followed by Games–Howell post hoc tests, with Bonferroni-adjusted values used for pairwise comparisons. The presence of orthodontic brackets can influence enamel mineralization because the bonding and debonding procedures modify the enamel surface microtopography. These procedures can generate microcracks and surface irregularities, which may affect mineral exchange between enamel and the surrounding environment. In our study, bracket removal led to a significant decrease in the mean atomic percentages of Ca (from 32.65% to 16.37% for sapphire) and P (from 16.35% to 8.60% for sapphire), accompanied by a sharp increase in surface roughness. After remineralization, Ca and P levels increased, while roughness decreased. However, neither the mineral content nor the surface topography fully returned to the initial values, indicating that remineralization achieved only a partial recovery of enamel integrity. These findings highlight that the integrated EDS approach and roughness analysis offer a promising descriptive framework for assessing enamel degradation and monitoring the effectiveness of remineralization therapies. The generated mathematical model provides a powerful descriptive framework for the in vitro data obtained, correlating roughness with mineral composition and treatment stage. However, such a high goodness-of-fit (R² > 0.98) should be interpreted cautiously due to the risk of overfitting. Therefore, rigorous external validation is mandatory before this model can be considered a reliable predictive tool. It also highlights the importance of enamel remineralization therapies after orthodontic treatment, but also the importance of choosing personalized treatment strategies adapted to the enamel type. Full article

Removing orthodontic brackets often presents clinical challenges, as it may cause patient discomfort, bracket fracture, or enamel damage resulting from strong adhesive bonds. Various techniques have been proposed to facilitate safer and more efficient debonding. Among them, laser-assisted methods have gained attention for their potential to minimize mechanical stress and improve patient comfort. The main objective of this study was to evaluate the effect of an erbium-doped yttrium–aluminum–garnet (Er:YAG) laser as an alternative to traditional mechanical methods for removing metal and ceramic orthodontic brackets. Materials and Methods: Thirty-six extracted premolars were prepared for bonding metal or ceramic brackets using a light-cure adhesive system. The control group consisted of six ceramic and six metal brackets removed with conventional orthodontic pliers. In the experimental groups, brackets were debonded using the Er:YAG laser (2940 nm, 0.6 mm spot size, 150 mJ; 15 Hz; (2.25 W) with an H14 handpiece. Irradiation time was recorded for each method, and teeth were rescanned to measure the surface area and volume of the crowns before and after bracket removal. Data were analyzed using one-way ANOVA and Tukey’s HSD test (p < 0.05). Scanning electron microscopy (SEM) was used for surface analysis. Results: A significant difference in debonding time (p = 0.001) was observed between the laser and traditional methods. The laser group took 52.5 s for metal and 56.25 s for ceramic brackets, compared to 1.05 s (metal) and 0.64 s (ceramic) in the traditional group. A significant difference in remaining cement volume was noted (p = 0.0002), but no differences were found between metal and ceramic brackets with laser removal. Conclusions: Er:YAG laser-assisted debonding is safe and minimally invasive but more time-consuming and costly than conventional methods, showing no improvement in clinical efficiency under current parameters. Full article

Background: Enamel surface roughness after bracket debonding is an important issue due to its impact on plaque accumulation and the potential development of carious lesions. This in vitro study aimed to assess enamel roughness after the removal of metallic and sapphire brackets and the effect of a remineralization treatment. Methods: Two hundred extracted human permanent teeth with healthy enamel were randomly distributed into two groups (n = 100) and bonded with either metallic or sapphire brackets using the same adhesive (3M™ Transbond™ XT (St. Paul, MN, USA), Minnesota Mining and Manufacturing Company, MN, USA). The enamel surface roughness was measured before bonding, after debonding, and after remineralization using SEM and a TR200 roughness (SaluTron GmbH, Frechen, Germany) tester. The parameter Ra was used to quantify the surface roughness. One-way ANOVA, the normality test, variance homogeneity, and the Bonferroni post hoc test were used to analyze the data. Results: Debonding significantly increased the enamel surface roughness in both groups. The sapphire bracket group presented significantly higher mean Ra values post debonding (4.14 ± 0.36 µm) compared to the metallic group (2.56 ± 0.52 µm). Remineralization led to a decrease in surface roughness in both groups, though not to baseline levels. The changes were statistically significant (p < 0.01), with a power of the test of 1.0. Conclusions: The bracket material significantly affects enamel surface roughness after orthodontic debonding. Sapphire brackets produced greater surface irregularities than metallic ones. Remineralization partially reduced roughness in both groups, with the final values in the metallic group being closer to baseline levels. Crucially, these values remained far above the clinical threshold for plaque retention, highlighting the need for improved debonding techniques. Full article

Background: In adhesive dentistry, debonding-on-demand is attractive for situations where no permanent attachment is required. Due to its destructive nature, ultraviolet (UV) light may be of interest for attenuating bond forces. The aim of this study was to investigate the impact of UV light on the shear bond strength (SBS) of etch-and-rinse (n = 4) and universal adhesives (n = 3). Methods: Glass-ceramic samples were bonded to bovine enamel surfaces (n = 10/adhesive) and subjected to shear bond testing before and after exposure to UV light (320–390 nm, 126 Jcm⁻²). Data was statistically analyzed by Mann–Whitney U test. Results: Initial photopolymerized etch-and-rinse adhesives showed superior SBS compared to universal adhesives. Highest values were recorded for iBOND^® Total etch (15.48 MPa) and Syntac classic© (17.60 MPa). Lowest SBS was obtained for Ecosite Bond^® (2.63 MPa). Additional UV exposure caused a significant decrease in SBS among iBOND Total etch (5.24 MPa, p = 0.009) and Solobond M© (3.65 MPa, p = 0.005), while for Syntac classic©, an increase (24.12 MPa, p = 0.047) was recorded. Among all other tested adhesives, no significant changes were observed. Conclusions: UV radiation impacted SBS of etch-and-rinse adhesives only (decrease: iBOND Total Etch, Solobond M; enhancement: Syntac classic©). Further research should focus on introducing sufficient light-triggered debonding mechanisms. Full article

Introduction: Digital planning and evolution of technology is allowing dentistry to be more efficient in time than before. In orthodontics the main purpose is to obtain fewer patient visits and to reduce the bonding time. For that, indirect bonding planned with CAD-CAM softwares is used to obtain a shorter treatment period, in general, and less chair-time. This waste of chair-time should also be reduced in other fields of dentistry such as endodontics, surgery, prosthodontics, and aesthetics. Methods: A total of 504 teeth were embedded into epoxy resin models mounted as a dental arch. Customized lingual multibracket appliances were bonded by a current adhesion protocol. After that, they were debonded, the polishing of cement remnants was performed with three different burs and two drills. The polishing time of each group was recorded by an iPhone 14 chronometer. Results: Descriptive and comparative statistical analyses were performed with the different study groups. Statistical differences (p < 0.005) between diamond bur and tungsten carbide and white stone burs and turbine were obtained, with the first being the slowest of them. Discussion: Enamel roughness was widely studied in orthodontics polishing protocol as the main variable for protocols establishment. However, in lingual orthodontics, due the difficulty of the access to the enamel surfaces, the protocol is not clear and efficiency should be considered. It was observed that the tungsten carbide bur is the safest bur. It was also recommended that a two-step protocol of polishing by tungsten carbide bur be followed by polishers. Conclusions: A tungsten carbide bur mounted in a turbine was the most efficient protocol for polishing after lingual bracket debonding. Full article

This study aimed to present a new application of 3D printing technology for crowns integrated with orthodontic brackets as one unit and to assess the strength of the bonded groups and the one-unit printed group. A total of 60 lateral incisors with brackets were obtained and allocated into two main groups: bonded groups and one-unit group. For the bonded groups, there were 40 specimens (20 conventionally fabricated crowns and 20 3D-printed crowns with bonded brackets), while for the one-unit group, there were 20 3D-printed crowns and brackets fabricated as one unit. One lateral incisor and one with a bracket were scanned, forming STL files for designing and printing 3D-printed specimens (20 without, 20 with brackets). Half of the specimens (30, n = 10) were thermocycled (5000 cycles). A universal testing machine was used for the bond strength (MPa) measurement, followed by analysis of the debonded areas and failure mode (adhesive, cohesive, or mixed). ANOVA and the post hoc Tukey’s test were used for analysis of the collected data (α = 0.05). The 3D-printed one-unit group significantly showed high strength compared with the bonded brackets (p < 0.001). The 3D-printed bracket showed the highest SBS (10.14 ± 1.93 MPa). After thermocycling, the bond strength of the bonded brackets significantly decreased (p < 0.001). The adhesive failure was dominant in the bonded groups, while the one-unit group exhibited all the fractures in the brackets. The introduced technique for producing a one-unit 3D-printed provisional crown integrated with orthodontic brackets is considered a clinically plausible option in contemporary orthodontic practice. However, further investigations are recommended to verify the findings of the present study before clinical implementation. Full article

Objective: The aim of this systematic review was to evaluate the effectiveness and safety of various laser systems for debonding ceramic orthodontic brackets compared to conventional mechanical removal methods. The primary outcomes assessed included enamel damage, pulp temperature changes, adhesive remnant index (ARI), and shear bond strength (SBS). Materials and Methods: A systematic search was conducted in November 2024 across the PubMed, Scopus, and Web of Science (WoS) databases following PRISMA guidelines. The initial search yielded 453 records, of which 41 studies met the inclusion criteria for qualitative and quantitative analysis. The risk of bias was assessed using a standardized scoring system, and only studies with accessible full texts were included. Results: The review highlighted significant heterogeneity in laser parameters, measurement protocols, and study methodologies. Among the evaluated lasers, CO₂ and Er:YAG were the most frequently studied and demonstrated high efficacy in debonding ceramic brackets while maintaining enamel integrity. Sixteen studies assessing SBS reported a reduction from baseline values of 13–23 MPa to clinically acceptable ranges of 7–12 MPa following laser application. ARI was analyzed in 25 studies, with laser-treated groups exhibiting higher scores (2–3), indicating safer debonding with more adhesive remaining on the tooth surface, thereby reducing enamel damage. Pulpal temperature increases were examined in 23 studies, revealing that most laser types, when used within optimal parameters, did not exceed the 5.5 °C threshold considered safe for pulpal health. However, diode and Tm:YAP lasers showed potential risks of overheating in some studies. Conclusions: Laser-assisted debonding of ceramic orthodontic brackets is an effective and safe technique when applied with appropriate laser parameters. CO₂ and Er:YAG lasers were the most effective in reducing SBS while preserving enamel integrity. However, variations in laser settings, study methodologies, and the predominance of in vitro studies limit the ability to establish standardized clinical guidelines. Further randomized controlled trials (RCTs) are necessary to develop evidence-based protocols for safe and efficient laser-assisted bracket removal in orthodontic practice. Full article

Objective: The aim of this systematic review was to evaluate the effectiveness and safety of various laser wavelengths for debonding orthodontic metal brackets compared to traditional plier-based methods. The primary outcomes assessed were enamel damage, pulp temperature changes, adhesive remnant index (ARI), and shear bond strength (SBS). Materials and Methods: In September 2024, an electronic search was performed across the PubMed, Web of Science (WoS), and Scopus databases, adhering to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines and the PICO framework. The initial search yielded 453 records. After eliminating 256 duplicates, 197 unique records were left for screening, which ultimately led to the qualification of 8 articles that met the inclusion criteria for both qualitative and quantitative analyses. The risk of bias in the articles was assessed by two independent reviewers. Results: The included studies demonstrated that laser-assisted debonding generally resulted in less adhesive residue on the enamel surface compared to conventional methods, as evidenced by the reductions in ARI scores reported in two studies. Temperature increases during laser use varied depending on the laser type and power settings. The Nd:YAG (neodymium-yttrium, aluminum, garnet) laser was found to cause significant temperature rises, posing a potential risk to pulp tissue, while the Er:YAG (erbium—yttrium, aluminum, garnet) and Er,Cr:YSGG (erbium, chromium—yttrium, scandium, gallium, garnet) lasers produced only negligible increases in pulp temperature. SBS comparisons revealed no significant differences between the laser-assisted and traditional debonding methods. Additionally, diode lasers demonstrated the potential to minimize enamel damage, particularly when operated at lower power settings. Four publications were assessed as high quality (low risk of bias), and another four as moderate quality (average risk of bias). Conclusions: In conclusion, laser-assisted orthodontic metal bracket debonding, when conducted with appropriately calibrated parameters, is a safe method for preserving tooth tissue. However, its advantages appear to be minimal compared to conventional plier-based methods, highlighting the need for further research to justify its broader clinical application. Full article

The quality of the enamel plays a critical role in the retention and performance of orthodontic brackets. This systematic review and meta-analysis aimed to evaluate the effect of resin infiltration pretreatment on the shear bond strength (SBS) of orthodontic brackets. An electronic search was conducted in October 2024 using PubMed, Web of Science (WoS), and Scopus databases, employing the keywords (resin infiltration AND bracket); (ICON AND bracket). The review adhered to PRISMA guidelines and utilized the PICO framework. Of the 143 articles initially identified, 63 underwent screening. Strict inclusion criteria were applied of which the most important were resin infiltration pretreatment, studies conducted on natural teeth and SBS evaluation. This left 19 studies for final analysis. The risk of bias was assessed using the checklist for quasi-experimental studies (Non-Randomized Experimental Studies) developed by the Joanna Briggs Institute (JBI). Among these, 13 studies used human teeth and 13 utilized Transbond XT as the adhesive. Metal brackets were predominantly examined (n = 17). The Adhesive Remnant Index (ARI) was assessed in 13 studies. Importantly, 11 studies concluded that resin infiltration significantly enhances SBS, 8 of which were conducted on human teeth. The meta-analysis revealed significantly higher SBS results when resin infiltrate was applied to healthy enamel. This finding underscores the dual benefits of resin infiltration: increased bond strength and the protection of enamel integrity during debonding procedures. The results suggest that resin infiltration not only improves the mechanical retention of orthodontic brackets but also serves as an enamel-preserving approach. Full article

The current study aimed to quantify the length progression of enamel microcracks (EMCs) after debonding metal and ceramic brackets, implementing OCT as a diagnostic tool. The secondary objectives included a three-dimensional assessment of EMC width and depth and the formation of new EMCs. OCT imaging was performed on 16 extracted human premolars before bonding and after debonding. Debonding was conducted with a universal Instron machine, with ARI values recorded. Additionally, 2D and 3D OCT images were employed to detect EMC formation and progression. Enface images quantified the length, width, and number of EMCs, and the length and width were analyzed using Image J (1.54f) and MATLAB (R2014b), respectively. Sagittal cross-sectional images were used for EMC depth analysis. A paired t-test showed significant differences in the length, width, and number of EMCs after debonding (p-value < 0.05), while the Wilcoxon non-parametric test indicated significant EMC depth changes (p-value < 0.05). No significant results were identified for the EMC number in ceramic brackets and EMC depth in metal brackets. Three-dimensional OCT imaging monitored existing EMCs at higher risk of progression and detected new EMCs following orthodontic bracket debonding. This study provides novel insights into EMC progression regarding the length, width, depth, and number after debonding. Full article

Rebonding of orthodontic brackets to new positions during treatment with fixed orthodontic appliances is a common practice and it is important not to cause plastic deformation during bracket removal. The aim of this study was to evaluate the resistance of various brackets to compression and assess their thresholds for plastic deformation. 5 different groups of metal brackets (BioQuick, Damon Q, Experience, Mini Diamond, Mini Sprint II) were bonded to 85 extracted human central incisor teeth utilizing the same adhesive system (Transbond XT). Compressive forces were applied via Weingart forceps in order to mimic clinical setting with the Shimadzu Universal tester. Kruskall-Wallis and Mann-Whitney U tests were used for comparing groups. Damon Q group exhibited the highest yield point value (549.35 N), the highest ultimate strength value (764.50 N) and the highest failure/debonding point value (721.89 N). The lowest yield point value (211.73 N), the lowest ultimate strength value (224.07 N) and the lowest failure/debonding point value (121.71 N) were found in the Mini Diamond group. The ultimate strength point values of Damon Q and Experience brackets were higher compared to Mini Diamond, BioQuick and Mini Sprint II brackets (p < 0.05). No statistically significant difference between Damon Q and Experience brackets in terms of yield strength and ultimate strength values (p > 0.05) were observed. Adhesive Remnant Index (ARI) score was 3 for all debonded samples. It may be concluded that Damon Q brackets were more resistant to plastic deformation than Mini Diamond, BioQuick and Mini Sprint II brackets (p < 0.05). Full article