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American Journal of Orthodontics and... Jan 2022As a result of the rapid spread of the disease caused by severe acute respiratory syndrome coronavirus 2, the World Health Organization declared a global pandemic on...
INTRODUCTION
As a result of the rapid spread of the disease caused by severe acute respiratory syndrome coronavirus 2, the World Health Organization declared a global pandemic on March 11, 2020. Governments worldwide adopted various measures to stop or slow the spread of coronavirus disease 2019 (COVID-19). One widely used measure was lockdown; workers who could work from home were instructed to do so, and nonessential businesses-including dental clinics-were closed for weeks or months. The purpose of this investigation was to document the incidence of fixed orthodontic appliance failures and the periodontal health status of patients undergoing fixed orthodontic treatment during and after the lockdown period.
METHODS
The sample comprised 350 orthodontic patients (mean age, 16.85 ± 2.59 years; 249 female, 101 male) who underwent orthodontic and periodontal examinations in Adıyaman, Turkey, after a mean lockdown period of 103.7 ± 21.3 days. Frequencies of an orthodontic bracket, elastic ligature, molar band, and miniscrew failures of oral ulcers were recorded, and periodontal parameters were assessed. The effects of sex, age, and the bracket systems used in the patients on the frequencies of these failures were analyzed.
RESULTS
It was revealed that 15.42% (n = 54) of all patients had ≥1 bracket bonding failure, and 8.16% (n = 4) of the patients with miniscrew implantation had ≥1 miniscrew failure. The incidence of bracket bonding failure was significantly higher in men than in women. No significant relationship was found between periodontal parameters and bracket bonding failure. Plaque and gingival scores were higher than those reported for a similar population before a lockdown.
CONCLUSIONS
The results indicated that orthodontic appliances might have higher frequencies of failure during a lockdown than normal times, and lockdown periods may worsen the periodontal health status of the patients.
Topics: Adolescent; Adult; COVID-19; Communicable Disease Control; Female; Humans; Incidence; Male; Orthodontic Appliances; Orthodontic Brackets; Periodontal Index; SARS-CoV-2; Young Adult
PubMed: 34509332
DOI: 10.1016/j.ajodo.2021.01.022 -
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 -
Clinical Oral Investigations Jan 2024We aimed to develop a tool for virtual orthodontic bracket removal based on deep learning algorithms for feature extraction from bonded teeth and to demonstrate its...
OBJECTIVE
We aimed to develop a tool for virtual orthodontic bracket removal based on deep learning algorithms for feature extraction from bonded teeth and to demonstrate its application in a bracket position assessment scenario.
MATERIALS AND METHODS
Our segmentation network for virtual bracket removal was trained using dataset A, containing 978 bonded teeth, 20 original teeth, and 20 brackets generated by scanners. The accuracy and segmentation time of the network were tested by dataset B, which included an additional 118 bonded teeth without knowing the original tooth morphology. This tool was then applied for bracket position assessment. The clinical crown center, bracket center, and orientations of separated teeth and brackets were extracted for analyzing the linear distribution and angular deviation of bonded brackets.
RESULTS
This tool performed virtual bracket removal in 2.9 ms per tooth with accuracies of 98.93% and 97.42% (P < 0.01) in datasets A and B, respectively. The tooth surface and bracket characteristics were extracted and used to evaluate the results of manually bonded brackets by 49 orthodontists. Personal preferences for bracket angulation and bracket distribution were displayed graphically and tabularly.
CONCLUSIONS
The tool's efficiency and precision are satisfactory, and it can be operated without original tooth data. It can be used to display the bonding deviation in the bracket position assessment scenario.
CLINICAL SIGNIFICANCE
With the aid of this tool, unnecessary bracket removal can be avoided when evaluating bracket positions and modifying treatment plans. It has the potential to produce retainers and orthodontic devices prior to tooth debonding.
Topics: Orthodontic Brackets; Deep Learning; Dental Bonding; Dental Debonding; Microscopy, Electron, Scanning
PubMed: 38280038
DOI: 10.1007/s00784-023-05440-1 -
American Journal of Orthodontics and... Dec 2015The first straight-wire appliance was introduced over 40 years ago to increase the consistency and efficiency of orthodontic treatment. More recently, computer-aided... (Comparative Study)
Comparative Study
INTRODUCTION
The first straight-wire appliance was introduced over 40 years ago to increase the consistency and efficiency of orthodontic treatment. More recently, computer-aided design and computer-aided manufacturing (CAD/CAM) technology has been used to create individualized orthodontic appliances. The purpose of this study was to investigate the clinical effectiveness and efficiency of CAD/CAM customized orthodontic appliances compared with direct and indirect bonded stock orthodontic brackets.
METHODS
This retrospective study included 3 treatment groups: group 1 patients were direct bonded with self-ligating appliances, group 2 patients were indirect bonded with self-ligating appliances, and group 3 patients were indirect bonded with CAD/CAM self-ligating appliances. Complete pretreatment and posttreatment records were obtained for all patients. The American Board of Orthodontics (ABO) Discrepancy Index was used to evaluate the pretreatment records, and the posttreatment outcomes were analyzed using the ABO Cast-Radiograph Evaluation. All data collection and analysis were completed by 1 evaluator.
RESULTS
There were no statistically significant differences in the ABO Discrepancy Index or the ABO Cast-Radiograph Evaluation among the groups. Treatment times for the 3 groups were significantly different; the CAD/CAM group was the shortest at 13.8 ± 3.4 months, compared with 21.9 ± 5.0 and 16.9 ± 4.1 months for the direct bonded and indirect bonded groups, respectively. The number of treatment appointments for the CAD/CAM group was significantly fewer than for the direct bonded group.
CONCLUSIONS
The CAD/CAM orthodontic bracket system evaluated in this study was as effective in treatment outcome measures as were standard brackets bonded both directly and indirectly. The CAD/CAM appliance was more efficient in regard to treatment duration, although the decrease in total archwire appointments was minimal. Further investigation is needed to better quantify the clinical benefits of CAD/CAM orthodontic appliances.
Topics: Adolescent; Appointments and Schedules; Cephalometry; Computer-Aided Design; Dental Bonding; Female; Follow-Up Studies; Humans; Image Processing, Computer-Assisted; Male; Models, Dental; Orthodontic Appliance Design; Orthodontic Brackets; Photography; Printing, Three-Dimensional; Radiography, Panoramic; Retrospective Studies; Time Factors; Treatment Outcome
PubMed: 26672713
DOI: 10.1016/j.ajodo.2015.07.029 -
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 -
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 -
Medicina (Kaunas, Lithuania) Mar 2023: Orthodontic tooth movement (OTM) requires bone remodeling resulting from complex processes of aseptic inflammation. Recent studies have confirmed close interaction...
: Orthodontic tooth movement (OTM) requires bone remodeling resulting from complex processes of aseptic inflammation. Recent studies have confirmed close interaction between the immune and skeletal systems. In addition, various orthodontic appliances including fixed systems affect the sublingual microbial composition, and the likelihood of developing inflammatory reactions of the gums is high, especially early in the treatment period. It is known that these systems have both positive and negative effects on the humoral and cellular immune responses. The main aim of the study was to evaluate the influence of self-ligating and conventional brackets on the salivary concentrations of cytokines (IL-6, osteoprotegerin (OPG), TNF-alpha, and IFN-gamma) and cortisol as a marker of stress. : Forty patients were analyzed at baseline (T0) and 2 months (T2) after fixing self-ligating (Ormco Damond Q) and conventional brackets (Ormco Mini Diamond). Salivary cytokine and cortisol concentrations were evaluated by commercial ELISA kits. : Outcomes of our study showed that after two months of treatment with either of these brackets, IFN-gamma and IL-6 levels did not change. However, TNF-alpha decreased with self-ligating brackets (13.36 to 8.32, = 0.002). The self-ligating bracket system also affects OPG concentration and cortisol levels 2 months after orthodontic activation. The level of OPG in the group of self-ligating brackets decreased significantly (8.55 to 2.72, = 0.003). Cortisol concentration was significantly higher in the self-ligation group (25.72 to 48.45, = 0.001) due to the effect of sustained strength movements. : Thus, the use of self-ligating and conventional brackets has a different effect on the concentration of cortisol and cytokines (OPG and TNF-alpha) in saliva 2 months after their fixation. Further longitudinal studies are necessary to explore why OPG levels are decreased in case of self-ligating cases and how OPG levels are related to clinical improvement.
Topics: Humans; Hydrocortisone; Orthodontic Wires; Orthodontic Brackets; Cytokines; Tumor Necrosis Factor-alpha; Interleukin-6
PubMed: 36984567
DOI: 10.3390/medicina59030566 -
Clinical Oral Investigations Jun 2021To investigate the clinical and in vitro performance of single-component orthodontic adhesives under metal brackets.
OBJECTIVES
To investigate the clinical and in vitro performance of single-component orthodontic adhesives under metal brackets.
MATERIALS AND METHODS
Bimaxillary orthodontic treatment was required for sixty patients and 60 premolar teeth were divided into three groups (n: 20). The single-component orthodontic adhesives Biofix and GC Ortho Connect (GC) that did not require primers were compared to the control group using Transbond XT, which was applied with a primer. For each patient, total bonding time was measured. The Adhesive Remnant Index (ARI) score was noted over 12 months. In vitro tests were used to evaluate specimens, shear bond strength (SBS), ARI, and Enamel Surface Index (ESI). After in vitro debonding, the enamel surface and bracket base were analyzed using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX).
RESULTS
Clinical failure rate with primer was 9.0%, while it was 8.0 and 10.0 for GC and Biofix, respectively. The mean in vitro SBS values of the Biofix, GC, and Transbond XT groups were 8.21, 8.07, and 7.37 MPa, respectively. There were no statistically differences in clinical failure (p = 0.160) and SBS values (p = 0.158). Mean differences in bond-up time per jaw were 9.65, 10.51, and 11.97 min, which were statistically significant (p = 0.0001).
CONCLUSION
Single-component adhesives had acceptable SBS values and enamel effects according to SEM-EDX analysis. Clinically, bonding failure was not shown statistically inferior to bonding with primer. There was also a significant difference in bond-up times.
CLINICAL RELEVANCE
Considering an intensely working clinic with bonding processes for at least two jaws per day, this means a saving of the chair time of 1 patient per week. However, better saliva contamination and moisture control with lack of the primer stage and, thereby, an acceptable bracket failure rate will bring clinically significant results with less chair time for clinicians.
Topics: Dental Bonding; Dental Cements; Dental Stress Analysis; Humans; Materials Testing; Orthodontic Brackets; Resin Cements; Shear Strength; Surface Properties
PubMed: 33404765
DOI: 10.1007/s00784-020-03729-z -
Computer Methods and Programs in... Mar 2021Four tie wings brackets are widely used in orthodontics, while the Six Tie Wings Brackets (STWB) are recently emerging in fixed orthodontic appliances due to their claim...
BACKGROUND AND OBJECTIVES
Four tie wings brackets are widely used in orthodontics, while the Six Tie Wings Brackets (STWB) are recently emerging in fixed orthodontic appliances due to their claim for less friction and thus faster teeth movement. The aim of this work was to evaluate the stress distribution and deformation during simulated mesio-distal tipping forces in Stainless Steel (SS) six tie wings orthodontic bracket using Finite Element Analysis (FEA).
METHODS
A six tie wings bracket (Synergy®, RMO, USA) dimensions were measured using the Vision system and a 3D model of the bracket was constructed. A Finite Element (FE) model was developed and mesio-distal tipping forces of 1.22 N to 1.96 N (125 to 200 gm) in increments were applied on the gingival and incisal slot walls. The stress distribution and deformation were recorded at specific points in the bracket and analyzed.
RESULTS
The maximum deformation and stress distribution for the mesial and distal tipping forces of 1.96 N were recorded as 0.137 µm and 10.60 MPa respectively. The stress concentration was more at the junction of the slot wall and the slot base. For mesial tipping,the deformation was more on the disto-incisal and mesio-gingival tie wings. Similarly, for distal tipping the deformation was more on the mesio-incisal and disto-gingival tie wings. The mid-tie wings showed minimal deformation during both distal and mesial tipping.
CONCLUSIONS
Our study visualized both the mesial and distal tipping forces induced stress distribution in the bracket tie wing-slot junctions. The deformation was present maximum in the mesio-incisal and disto-incisal tie wings and minimal in the mid-tie wings. Clinicians should be aware of this behavior of STWB in making decisions to alter the tipping forces in the archwire to compensate for the tie wing deformation in refining the teeth position.
Topics: Finite Element Analysis; Materials Testing; Orthodontic Appliance Design; Orthodontic Brackets; Orthodontic Wires
PubMed: 33218706
DOI: 10.1016/j.cmpb.2020.105835 -
Journal of Orofacial Orthopedics =... Jan 2022Gummetal® (Maruemu Works, Osaka, Japan), a new orthodontic wire material successfully used in clinical applications since 2006, is biocompatible and exhibits...
OBJECTIVES
Gummetal® (Maruemu Works, Osaka, Japan), a new orthodontic wire material successfully used in clinical applications since 2006, is biocompatible and exhibits exceptionally high elasticity, nonlinear elastic behavior, plasticity and strength. Systematic comparisons of friction behavior are lacking; thus, the friction of Gummetal® in the binding modus was compared to commonly used low friction wires.
MATERIALS AND METHODS
In vivo tests were run with Gummetal®, CoCr (cobalt-chromium Elgiloy®, Rocky Mountain Orthodontics, Denver, CO, USA), β‑Ti (β-Titanium TMA®, Ormco, Orange, CA, USA), NiTi (nickel-titanium, NiTi-SE, Dentalline, Birkenfeld, Germany), and stainless steel (SS; Ref. 251-925, 3M Unitek, Monrovia, CA, USA) [dimensions: 0.014 inch (0.35 mm), 0.016 inch (0.40 mm), 0.016 × 0.022 inch (0.40 × 0.56 mm), and 0.019 × 0.025 inch (0.48 × 0.64 mm)-β-Ti not available in the dimension 0.014 inch]. These were combined with Discovery® (Dentaurum, Ispringen, Germany), Micro Sprint® (Forestadent, Pforzheim, Germany), Clarity™ (3M Unitek), and Inspire Ice™ (Ormco) and slots in the dimension 0.022 inch (0.56 mm) and, except for the 0.019 × 0.025 inch wires, in the dimension 0.018 inch (0.46 mm). They were ligated with a 0.010 inch (0.25 mm) steel ligature (Smile Dental, Ratingen, Germany). Brackets were angulated by applying a moment of force of 10 Nmm against the wire, which was pulled through the slot at 0.2 mm/s.
RESULTS
In 660 tests using 132 bracket-wire combinations, friction loss for Gummetal® was comparable to and, in a few combinations with Micro Sprint®, significantly lower (p < 0.05) than SS and CoCr. The friction for Gummetal® was significantly lower (p < 0.05) than NiTi, and β‑Ti. In some bracket-wire combinations, lower friction was found with round wires compared to rectangular wires, except for the combination with Inspire Ice™, which was higher but not significant. Slot size did not have a significant effect on friction in most combinations.
CONCLUSION
The low friction associated with Gummetal® wires during arch-guided tooth movement will be a valuable addition to the armamentarium of orthodontists.
Topics: Dental Alloys; Dental Stress Analysis; Friction; Materials Testing; Orthodontic Appliance Design; Orthodontic Brackets; Orthodontic Wires; Titanium
PubMed: 34228140
DOI: 10.1007/s00056-021-00317-y