-
The Angle Orthodontist May 2009To examine the influence of third-order torque on kinetic friction in sliding mechanics involving active and passive self-ligating brackets. (Comparative Study)
Comparative Study
OBJECTIVE
To examine the influence of third-order torque on kinetic friction in sliding mechanics involving active and passive self-ligating brackets.
MATERIALS AND METHODS
Wire-slot frictional forces were quantified and compared across five sets of brackets and tubes within a simulated posterior dental segment with -15 degrees , -10 degrees , -5 degrees , 0 degrees , +5 degrees , +10 degrees , and +15 degrees of torque placed in the second-premolar bracket; a working archwire was pulled through the slots.
RESULTS
Increasing the torque from 0 degrees to +/-15 degrees produced significant increases in frictional resistance with all five sets of brackets and tubes. At 0 degrees and +/-5 degrees of torque, generally less friction was created within the passive than within the active self-ligating bracket sets, and the conventional bracket sets with elastomeric ligation generated the most friction. At +/-10 degrees of torque, apparently with wire-slot clearance eliminated, all bracket-and-tube sets displayed similar resistances, with one exception at +10 degrees . At +/-15 degrees of torque, one passive set and one active set produced significantly larger frictional resistances than the other three sets.
CONCLUSIONS
Third-order torque in posterior dental segments can generate frictional resistance during anterior retraction with the archwire sliding through self-ligating bracket slots. With small torque angles, friction is less with passive than with active self-ligating brackets, but bracket design is a factor. Frictional forces are substantial, regardless of ligation if the wire-slot torque exceeds the third-order clearance.
Topics: Dental Stress Analysis; Elastomers; Friction; Humans; Materials Testing; Orthodontic Appliance Design; Orthodontic Brackets; Orthodontic Wires; Surface Properties; Tooth Movement Techniques; Torque
PubMed: 19413378
DOI: 10.2319/022608-114.1 -
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 -
BioMed Research International 2021This pre-post study is aimed at determining the effects of masticatory muscle activity (masseter and temporalis) measured via sEMG between conventional, self-ligating,...
OBJECTIVE
This pre-post study is aimed at determining the effects of masticatory muscle activity (masseter and temporalis) measured via sEMG between conventional, self-ligating, and ceramic bracket after six months of orthodontic treatment.
METHODS
A total of eighteen (18) malocclusion patients were identified. Malocclusion patients were subdivided into 3 groups based on the bracket selection (conventional, self-ligating, and ceramic bracket) with 6 patients for each group. sEMG of muscles were done using a two-channel electromyography device, where pregelled and self-adhesive electrodes (bilateral) were applied. Chewing and clenching of masseter and temporalis muscle activity were recorded for 20 s pre and 6 months of orthodontic treatment using sEMG (frequency 60 Hz). The data were analysed by using repeated measures ANOVA in IBM SPSS Statistics Version 24.0.
RESULTS
Chewing and clenching for masseter muscle showed no significant difference ( > 0.05) in sEMG activity of three types of the brackets. However, for temporalis muscle, there was a significant difference found in sEMG activity during chewing ( < 0.05) and clenching ( < 0.05) between these three brackets.
CONCLUSION
The activity of temporalis muscle showed significant changes in chewing and clenching, where the conventional group demonstrated better muscle activity pre and at six months of fixed appliances.
Topics: Electrodes; Electromyography; Female; Humans; Male; Masseter Muscle; Mastication; Orthodontic Brackets; Temporal Muscle
PubMed: 33969121
DOI: 10.1155/2021/6642254 -
The Angle Orthodontist Jan 2012To test the null hypothesis that there is no significant difference in the shear bond strength (SBS) and Adhesive Remnant Index (ARI) scores of new vs reconditioned... (Comparative Study)
Comparative Study
OBJECTIVE
To test the null hypothesis that there is no significant difference in the shear bond strength (SBS) and Adhesive Remnant Index (ARI) scores of new vs reconditioned self-ligating brackets.
MATERIALS AND METHODS
One hundred and twenty permanent extracted bovine teeth were embedded in resin blocks. Three different new and reconditioned self-ligating orthodontic brackets (Smart Clip [3M Unitek]; Quick [Forestadent]; and Damon3MX [Ormco]) were tested. Scanning electron microphotographs of the different new (groups 1, 3, and 5) and reconditioned (groups 2, 4, and 6) bracket bases were taken before starting the experiments. Brackets were then bonded to the teeth using an orthodontic adhesive and were then tested in shear mode using an Instron Universal Testing Machine. ARI scores were then recorded. Statistical analysis was performed to determine significant differences in SBS and ARI Scores.
RESULTS
Smart Clip and Damon3MX reconditioned brackets showed significantly lower SBS than did new ones. On the contrary, Quick reconditioned brackets showed significantly higher SBS than did new ones. No significant differences in ARI scores were found after the reconditioning process for the three different brackets tested.
CONCLUSION
The in-office reconditioning procedure alters the SBS of self-ligating brackets, although SBS values still remain clinically acceptable.
Topics: Animals; Cattle; Dental Bonding; Dental Debonding; Dental Enamel; Dental Stress Analysis; Equipment Reuse; Materials Testing; Orthodontic Brackets; Shear Strength; Stress, Mechanical; Surface Properties
PubMed: 21806464
DOI: 10.2319/033011-227.1 -
Dental and Medical Problems 2022As per the Centers for Disease Control and Prevention (CDC) guidelines, dentists must avoid the aerosol-generating procedures during the severe acute respiratory...
Comparison of bracket bond failure with the aerosol-generating and novel non-aerosol-generating bonding techniques during the SARS-CoV-2 pandemic among orthodontic patients: A retrospective cohort study.
BACKGROUND
As per the Centers for Disease Control and Prevention (CDC) guidelines, dentists must avoid the aerosol-generating procedures during the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic.
OBJECTIVES
This study aimed to compare the rate of bracket bond failure with the aerosol-generating and non-aerosol generating bonding techniques.
MATERIAL AND METHODS
A retrospective cohort study was conducted during the SARS-CoV-2 pandemic on a sample of 44 patients (880 teeth), equally divided into 2 groups: the conventional aerosol-generating bonding technique (ABT); and the novel non-aerosol-generating bonding technique (NABT). The rate of bracket survival and total number of bracket breakages in the 2 groups were assessed by means of the survival regression analysis. The influence of pre-treatment factors, such as the sagittal jaw relationship (ANB), the Frankfort-mandibular plane angle (FMA), overjet, overbite, and upper and lower crowding, on the rate of bracket survival was also evaluated.
RESULTS
There was a statistically significant difference between ABT and NABT in terms of bracket survival. The mean bracket survival with ABT was 176.21 ±77.89 days and with NABT it was 162.53 ±83.34 days. The novel technique showed a hazard ratio of bracket survival of 2.99 as compared to the conventional method. There was a statistically significant influence of overjet on the rate of bracket survival (p = 0.010). The posterior segment had a higher rate of bracket failure as compared to the anterior segment in NABT, which was statistically significant (p < 0.001). However, this difference was statistically non-significant in the case of ABT.
CONCLUSIONS
There was an increased rate of bracket failure with NABT as compared to ABT. The rate of bracket breakages in the anterior quadrants was comparable for both bonding techniques.
Topics: COVID-19; Dental Bonding; Humans; Orthodontic Brackets; Pandemics; Retrospective Studies; SARS-CoV-2; United States
PubMed: 35775411
DOI: 10.17219/dmp/146791 -
Tomography (Ann Arbor, Mich.) Jul 2023This study's aim is to determine the accuracy and precision of the bracket slot height in MBT 0.022″ ceramic brackets. Five brackets from 11 different systems (n = 55)...
This study's aim is to determine the accuracy and precision of the bracket slot height in MBT 0.022″ ceramic brackets. Five brackets from 11 different systems (n = 55) were scanned using micro-computed tomography (micro-CT). The slot height was measured at the face (external) and base (internal) of the slot. Data were analyzed using a One-Sample -Test, and a Paired -Test. The lowest external height was seen in OrthoCare Purity at 0.02264″ (2.9%), and the greatest in TOC Ghost Advanced at 0.02736″ (24.4%). The lowest internal height was seen in Forestadent Glam at 0.02020″ (-8.2%), and the greatest in TOC Ghost Advanced at 0.2547″ (15.8%). OrthoCare Purity measurements corresponded most closely with the expected measurements. TP InVu was found to be the most precise bracket for external height (range = 0.00043″) and American Orthodontics 20/40 for internal height (range = 0.00028″). In assessing slot geometry, all brackets demonstrated a higher mean external slot height compared to the internal measurements at the base of the bracket. Orthodontic bracket slots are larger than expected and slot parallelism was not observed in any bracket brand tested. Similarly, slot dimensions are imprecise where two 'identical' brackets have different slot sizes. The clinician should, therefore, assume that play is most likely higher than expected.
Topics: Orthodontic Appliance Design; X-Ray Microtomography; Orthodontic Brackets; Ceramics
PubMed: 37489477
DOI: 10.3390/tomography9040109 -
Progress in Orthodontics May 2022To compare the fluorescent properties of 6 different orthodontic adhesives and provide useful information for clinicians in the adhesion choice, in order to remove it...
BACKGROUND
To compare the fluorescent properties of 6 different orthodontic adhesives and provide useful information for clinicians in the adhesion choice, in order to remove it easily at the end of orthodontic treatment by using the Fluorescence-aided Identification Technique (FIT).
METHODS
Six orthodontic adhesives were included: Ortho Connect, Gradia LoFlo A3.5, Greengloo, Transbond XT, KommonBase Pink, and KommonBase Clear. The same thermoformed template with 1 mm shell thickness on the six anterior teeth was used for adhesive positioning; furthermore, an ultraviolet light-emitting diode flashlight was used for the FIT. The brightness of adhesive area and tooth area (L* color coordinate) were measured on the photographs by using the "color picker" tool of Photoshop software.
RESULTS
GC Ortho Connect, Gradia Direct LoFlo and KommonBase Clear showed the highest differences of brightness (15.5, 16.3 and 13.5, respectively), while Greengloo, Transbond XT and KommonBase Pink registered similar values between resin area and tooth area with FIT (- 0.5, - 0.8 and - 1.0, respectively). The high viscosity adhesive resins, as Greengloo and Transbond XT, showed a similar performance in terms of fluorescence to the KommonBase Pink, the lowest viscous resin adhesive considered.
CONCLUSIONS
The most used orthodontic adhesives showed different fluorescence properties. Some resins were brighter with the FIT, facilitating identification and subsequent removal. Other orthodontic adhesives presented no difference between adhesive and tooth. The viscosity of orthodontic adhesives did not influence the brightness emitted with FIT.
Topics: Composite Resins; Dental Bonding; Dental Cements; Dental Stress Analysis; Humans; Materials Testing; Orthodontic Brackets; Resin Cements; Shear Strength
PubMed: 35599253
DOI: 10.1186/s40510-022-00411-w -
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 -
International Journal of Environmental... Mar 2023Bracket bonding failure is one of the relevant problems in fixed orthodontics therapy, which affects the total treatment and quality of treatment results. The purpose of...
BACKGROUND
Bracket bonding failure is one of the relevant problems in fixed orthodontics therapy, which affects the total treatment and quality of treatment results. The purpose of this retrospective study was to evaluate the frequency of bracket bond failure and find out risk factors.
METHODS
A total of 101 patients with an age range of 11-56 years were included in this retrospective study and treated for a mean period of 30.2 months. Inclusion criteria were: males and females with permanent dentition and completed orthodontic treatment in both fully bonded dental arches. Risk factors were calculated using binary logistic regression analysis.
RESULTS
The overall bracket failure rate was 14.65%. The bracket failure rate was significantly higher in the younger patients' group ( = 0.003). In most cases, patients experienced bracket failures in the first month of the treatment. Most of the bracket bond failures occurred on the left lower first molar (29.1%) and were twice as common in the lower dental arch (66.98%). Patients with increased overbite had an increased likelihood of bracket loss ( = 0.042). Class II malocclusion increased the relative risk of bracket failure, while Class III decreased the rate of bracket failure, but the difference was not statistically significant ( = 0.093).
CONCLUSIONS
The bracket bond failure rate was higher in younger patients than in older patients. Brackets placed on mandibular molars and premolars had the highest failure rate. Class II was associated with an increased bracket failure rate. Increased overbite statistically significantly increases bracket failure rate.
Topics: Male; Female; Humans; Aged; Infant; Child, Preschool; Retrospective Studies; Overbite; Incidence; Resin Cements; Orthodontic Brackets; Risk Factors
PubMed: 36901461
DOI: 10.3390/ijerph20054452 -
Scanning 2013In this study, we tested the surface roughness of bracket slots and the friction coefficient between the bracket and the stainless steel archwire before and after...
In this study, we tested the surface roughness of bracket slots and the friction coefficient between the bracket and the stainless steel archwire before and after orthodontic treatment. There were four experimental groups: groups 1 and 2 were 3M new and retrieved brackets, respectively, and groups 3 and 4 were BioQuick new and retrieved brackets, respectively. All retrieved brackets were taken from patients with the first premolar extraction and using sliding mechanics to close the extraction space. The surface roughness of specimens was evaluated using an optical interferometry profilometer, which is faster and nondestructive compared with a stylus profilometer, and provided a larger field, needing no sample preparation, compared with atomic force microscopy. Orthodontic treatment resulted in significant increases in surface roughness and coefficient of friction for both brands of brackets. However, there was no significant difference by brand for new or retrieved brackets. These retrieval analysis results highlight the necessity of reevaluating the properties and clinical behavior of brackets during treatment to make appropriate treatment decisions.
Topics: Friction; Humans; Interferometry; Orthodontic Brackets; Orthodontics; Surface Properties
PubMed: 23086715
DOI: 10.1002/sca.21060