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Asian Journal of Surgery Jul 2022
Topics: Artifacts; Hernia; Humans; Magnetic Phenomena; Magnetic Resonance Imaging; Orthodontic Brackets
PubMed: 35346588
DOI: 10.1016/j.asjsur.2022.02.043 -
American Journal of Orthodontics and... Dec 1993
Topics: Dental Debonding; Equipment Reuse; Humans; Informed Consent; Orthodontic Brackets; Orthodontics; Risk Management; Sterilization
PubMed: 8249938
DOI: 10.1016/S0889-5406(05)80447-0 -
BioMed Research International 2022Failure of brackets is a common problem in orthodontics. This affects the treatment time, cost, and compliance of the patient. This study was conducted to estimate the...
Failure of brackets is a common problem in orthodontics. This affects the treatment time, cost, and compliance of the patient. This study was conducted to estimate the bracket failure rate and the related factors for the long term. This ambidirectional cohort study included 150 nonsyndromic orthodontic patients undergoing fixed appliance therapy for the last two years. The same patients were followed for 7 months. Different variables related to bracket failure were evaluated. The available data were analyzed descriptively, and the Kaplan-Meier estimate was used to measure the bracket survival rate from the date of bonding to failure. . A total of 180 bracket bond failures in the 150 included patients (52.2% males and 47.8% females) with a median age of 17 years (range 10-25 years). 69% of brackets failures were reported within the first 6 months after bonding. About 58.3% of bracket failure was noticed in adolescent patients before the age of 18 years. The majority of the cohort (81.1%) has good oral hygiene. The failure rate in patients with normal overbite was 41.1%, in decreased overbite cases was 15%, while in deep bite cases the failure rate was 43.9% with a statistically significant difference. Adults show less bracket failure (41.7%) than adolescent patients (58.3%). More bracket failure was noted in the lower arch (55%) than the upper arch (45%), and there were more bond failures posteriorly (61%) than on the anterior teeth (39%). Majority (41.1%) of the bracket failed on round NiTi wires. . The bracket failure rate was 6.4%, with most bracket failure occurring in the first 6 months after bonding with individual difference. There was more incidence of bond failure in an increased overbite, adolescents, lower arch, posterior teeth, and lighter alignment wires.
Topics: Adolescent; Adult; Child; Equipment Failure Analysis; Female; Humans; Incidence; Male; Orthodontic Brackets
PubMed: 35059463
DOI: 10.1155/2022/5128870 -
BioMed Research International 2021To compare the orthodontic bracket debonding force and assess the bracket failure pattern clinically between different teeth by a validated 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. . 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 -test to compare in vivo bracket debonding force, Cohen's kappa (), and a nonparametric Kruskal-Wallis test for the reliability and the assessment of ARI scoring.
RESULTS
A significant difference ( < 0.001) of mean debonding force was found between different types of teeth in vivo. Clinically, ARI scores were not significantly different ( = 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.
Topics: Adult; Dental Cements; Device Removal; Equipment Failure; Humans; Mechanical Phenomena; Orthodontic Brackets; Tooth; Young Adult
PubMed: 33959664
DOI: 10.1155/2021/6663683 -
The Journal of Adhesive Dentistry 2019To evaluate shear bond strength (SBS), adhesive remnant index (ARI), and orthodontic bracket base after debonding of orthodontic brackets bonded using two different...
PURPOSE
To evaluate shear bond strength (SBS), adhesive remnant index (ARI), and orthodontic bracket base after debonding of orthodontic brackets bonded using two different adhesives.
MATERIALS AND METHODS
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).
RESULTS
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).
CONCLUSION
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.
Topics: Dental Bonding; Dental Cements; Dental Stress Analysis; Humans; Materials Testing; Orthodontic Brackets; Resin Cements; Shear Strength; Surface Properties
PubMed: 31802071
DOI: 10.3290/j.jad.a43652 -
International Orthodontics Jun 2019The aim of this study was to determine the risk factors associated with orthodontic bracket bond failure and to develop a prediction equation for orthodontic bracket...
The aim of this study was to determine the risk factors associated with orthodontic bracket bond failure and to develop a prediction equation for orthodontic bracket bond failure rate using the risk factors. This was a retrospective cohort study conducted on a sample of 690 brackets in orthodontic patients aged 10 to 28 years old (mean age 17.97±5.11 years old) visiting a dental hospital. The effect of various parameters of orthodontic bond strength was assessed on bracket failure rate using survival analysis. Parametric (exponential) regression analysis was used to determine the risk factors associated with bracket failure and a prediction equation was formulated to predict the bracket failure rate. The overall mean survival time for the brackets was 3.04 (2.9-3.17) years. The univariate analysis showed a statistically significant (P<0.05) association of bracket material, site, overjet, overbite, incisor and molar classification and age. The multivariate analysis showed a significant interaction between site and side along with bracket material, jaw, overjet and overbite in the model. The risk of bracket failure on the right posterior region is 7.7 times that in the right anterior region when adjusted for all other variables in the model (HR: 7.7; 95% CI: 4.3-13.6). The model including bracket material, jaw, overjet, overbite and interaction between site and side can be used as a predictor of hazard rate for orthodontic bracket failure. Care should be taken in bonding brackets in the posterior region, as their debonding rate is higher as compared to anterior region.
Topics: Adolescent; Adult; Child; Dental Bonding; Dentin-Bonding Agents; Equipment Failure; Female; Humans; Incisor; Male; Materials Testing; Molar; Orthodontic Appliance Design; Orthodontic Brackets; Retrospective Studies; Risk Factors; Shear Strength; Stress, Mechanical; Young Adult
PubMed: 30987959
DOI: 10.1016/j.ortho.2019.03.002 -
Proceedings of the Institution of... Aug 2021In orthodontic fixed appliance therapy, the archwire torque used to refine the teeth position during the treatment imparts significant forces inside the bracket slot....
In orthodontic fixed appliance therapy, the archwire torque used to refine the teeth position during the treatment imparts significant forces inside the bracket slot. The objective of this study was to measure the torque relevant bracket slot deformation in Stainless Steel (SS) brackets during various degree of archwire twist. Standard edgewise brackets 0.018-inch (in.)/0.022-in. each 20 no. and 0.016 × 0.022, 0.017 × 0.025, 0.019 × 0.025, and 0.021 × 0.025 in. archwires each 10 no. were used. A novel experimental setup consisting of loading fixture and torque key mounted on a Vision Measuring System (VMS) were used to measure the brackets slot deformation. The Top Slot and Middle Slot Deformations (TSD and MSD) of the brackets for 35° angle of twist in 0.016 × 0.022 in. archwire in 0.018-in. slot, 0.019 × 0.025 in. archwire in 0.022-in. slot and for 30° angle of twist in 0.017 × 0.025 in. archwire in 0.018-in. slot and 0.021 × 0.025 in. archwire in 0.022-in. slot were measured. Results showed that the mean TSD and MSD were higher when the archwire size, the slot size and the angle of twist were greater. In the evaluated bracket-archwire combinations, the TSD were higher than MSD and the bracket slots were elastically deformed within the clinically required 35° angle of twist in the archwire. Clinicians should be aware of this torque relevant bracket slot deformation which might be a factor for torque loss and suitably incorporate archwire angle of twist.
Topics: Dental Stress Analysis; Humans; Materials Testing; Orthodontic Appliance Design; Orthodontic Brackets; Orthodontic Wires; Stainless Steel; Torque
PubMed: 33962528
DOI: 10.1177/09544119211015086 -
The Angle Orthodontist May 2016To determine the consensus among studies that adhesive resin application improves the bond strength of orthodontic brackets and the association of methodological...
OBJECTIVE
To determine the consensus among studies that adhesive resin application improves the bond strength of orthodontic brackets and the association of methodological variables on the influence of bond strength outcome.
MATERIALS AND METHODS
In vitro studies were selected to answer whether adhesive resin application increases the immediate shear bond strength of metal orthodontic brackets bonded with a photo-cured orthodontic adhesive. Studies included were those comparing a group having adhesive resin to a group without adhesive resin with the primary outcome measurement shear bond strength in MPa. A systematic electronic search was performed in PubMed and Scopus databases.
RESULTS
Nine studies were included in the analysis. Based on the pooled data and due to a high heterogeneity among studies (I(2) = 93.3), a meta-regression analysis was conducted. The analysis demonstrated that five experimental conditions explained 86.1% of heterogeneity and four of them had significantly affected in vitro shear bond testing. The shear bond strength of metal brackets was not significantly affected when bonded with adhesive resin, when compared to those without adhesive resin.
CONCLUSIONS
The adhesive resin application can be set aside during metal bracket bonding to enamel regardless of the type of orthodontic adhesive used.
Topics: Acid Etching, Dental; Dental Bonding; Dental Cements; Dental Stress Analysis; Humans; Materials Testing; Orthodontic Brackets; Regression Analysis; Resin Cements; Shear Strength
PubMed: 26177358
DOI: 10.2319/041615-255.1 -
Journal of Biomechanics May 2021So far, no practicable procedure exists to quantify the orthodontic loads applied to teeth in vivo. Dentists therefore rely on experience and simplified mechanical...
So far, no practicable procedure exists to quantify the orthodontic loads applied to teeth in vivo. Dentists therefore rely on experience and simplified mechanical in-vitro experiments comprising deflection of orthodontic wires. Predicting the mechanical behaviour of orthodontic wires during clinical therapy requires understanding of the different contact states at multi-bracket-wire interfaces. This study experimentally investigates the effect of different bracket-wire contact configurations in a three-bracket setup and uses two numerical approaches to analyse and complement the experimental data. Commonly used round stainless-steel wires (diameter: 0.012″ and 0.016″) and titanium-molybdenum alloy wires (diameter: 0.016″ and 0.018″) were tested. All six force-moment components were measured separately for each of the three brackets. The results indicate that a specific sequence of distinct bracket-wire contact configurations occurs. Several transitions between configurations caused substantial changes of effective wire stiffness (EWS), which were consistent among experimental and numerical methods. The lowest EWS was observed for the configuration in which the wire touched only one wing of the lateral brackets. Taking this stiffness as 100%, the transition to a configuration in which the wire touched two opposing wings of the lateral brackets resulted in an increase of EWS of 300% ± 10%. This increase was independent of the wire type. Additional contacts resulted in further increases of stiffness beyond 400%. The results of this combined experimental and numerical study are important for providing a fundamental understanding of multi-bracket-wire contact configurations and have important implications for clinical therapy.
Topics: Dental Alloys; Dental Stress Analysis; Friction; Materials Testing; Orthodontic Brackets; Orthodontic Wires; Stainless Steel; Titanium
PubMed: 33894471
DOI: 10.1016/j.jbiomech.2021.110401 -
Brazilian Dental Journal 2020The aim of this study was to analyze the influence of orthodontic bracket type (metallic or ceramic) and mouthguard on biomechanical response during impact....
The aim of this study was to analyze the influence of orthodontic bracket type (metallic or ceramic) and mouthguard on biomechanical response during impact. Two-dimensional plane-strain models of a patient with increased positive overjet of the maxillary central incisor was created based on a CT scan, simulating the periodontal ligament, bone support, gingival tissue, orthodontic brackets (metallic or ceramic) and mouthguard. A nonlinear dynamic impact finite element analysis was performed in which a steel object hit the model at 1 m/s. Stress distributions (Von Mises and Modified Von Mises) and strain were evaluated. Stress distributions were affected by the bracket presence and type. Models with metallic and ceramic bracket had higher stresses over a larger buccal enamel impact area. Models with ceramic brackets generated higher stresses than the metallic brackets. Mouthguards reduced the stress and strain values regardless of bracket type. Mouthguard shock absorption were 88.37% and 89.27% for the metallic and ceramic bracket, respectively. Orthodontic bracket presence and type influenced the stress and strain generated during an impact. Ceramic brackets generated higher stresses than metallic brackets. Mouthguards substantially reduced impact stress and strain peaks, regardless of bracket type.
Topics: Ceramics; Dental Stress Analysis; Finite Element Analysis; Humans; Incisor; Materials Testing; Mouth Protectors; Orthodontic Appliance Design; Orthodontic Brackets; Stress, Mechanical
PubMed: 33146339
DOI: 10.1590/0103-6440202002818