The Influence of Bracket Material, Ligation Force and Wear on Frictional Resistance of Orthodontic Brackets

1993 ◽  
Vol 20 (2) ◽  
pp. 109-115 ◽  
Author(s):  
O. Keith ◽  
S. P. Jones ◽  
E. H. Davies

Planar static frictional phenomena were investigated for two types of ceramic and one type of stainless steel orthodontic bracket against rectangular stainless steel archwire. The brackets studied were ‘Starfire’ (single crystal aluminium oxide), ‘Allure III’ (polycrystalline aluminium oxide), and ‘Dentaurum’ (stainless steel). The investigative parameters were: bracket material, force of ligation and whether the brackets were new or ‘worn’. Without exception, both types of ceramic bracket produced greater frictional resistance than the stainless steel brackets throughout testing. At a ligation force of 500 g, the Starfire bracket gave the greatest frictional resistance. At ligation forces of 200 and 50 g, the greatest frictional resistance was seen with Allure III. After a period of simulated wear, frictional resistance of Starfire tended to increase at the greatest ligation load while that of both ceramics decreased slightly at the two lower ligation loads. The ceramic brackets caused abrasive wear of the archwire surfaces and the consequent wear debris may have contributed to the changes in frictional resistance seen with Starfire and Allure III. Dentaurm brackets produced minimal frictional resistance in any test and negligible change with wear.

2019 ◽  
Vol 20 (1) ◽  
Author(s):  
Liu Yang ◽  
Guangfu Yin ◽  
Xiaoming Liao ◽  
Xing Yin ◽  
Niansong Ye

Abstract Background This study aims to develop a novel process to establish a standardized manufacturing technique of customized esthetic ceramic bracket system (CCB) which could be endowed with individual color and shape to satisfy patients’ individual demands. Material characteristics and mechanical parameters of CCB were evaluated. Subjects and methods CCB virtual models were designed individually according to patient’s teeth morphology and clinical demands. 3D printing technology, lost-wax technology, and selected glass-ceramic ingots were employed to fabricate CCB. Scanning electron microscopy (SEM) analyses were performed to characterize the surface morphology of CCB and commercially available brackets (Clarity Advanced; Crystalline VII; Inspire ICE; Damon Q). Static and kinetic frictional resistance (FR), shear bond strength (SBS) and adhesive remnant index (ARI) scores were recorded. One-way analyses of variance (ANOVA) and post-hoc Tukey’s HSD multiple tests were used for statistical analyses. Results Multi-color and multi-transparency raw materials facilitated CCB with a wide range of color options and controllable optical properties to satisfy different esthetic demands of individual orthodontic patients. CCB presented same level of FR as commercially available ceramic brackets did. No significant differences (P ≥ 0.05) of SBS were observed among CCB-ES (treated silane), Clarity Advanced and Crystalline VII groups, and CCB-E (no silane) attained the highest ARI mean score 3. In the preliminary clinical trial, CCB presented excellent color-matching and shape-matching appearances similar to natural teeth, which made it highly invisible from social intercourse distance. Conclusions CCB were demonstrated to be an applicable labial orthodontic bracket system with optimized esthetics and biomechanics. We envision that it would be an ideal alternative for patients who pursue esthetic orthodontic treatment but were not likely to take lingual appliances or clear aligners.


2014 ◽  
Vol 4 (1) ◽  
pp. 22-28 ◽  
Author(s):  
Vinit Singh ◽  
Swati Acharya ◽  
Satyabrata Patnaik ◽  
Smruti Bhusan Nanda

Introduction: During sliding mechanics, frictional resistance is an important counterforce to orthodontic tooth movement; whichmust be controlled to allow application of light continuous forces.Objective: To investigate static and kinetic frictional resistance between three orthodontic brackets: ceramic, self-ligating, andstainless steel, and three 0.019×0.025” archwires: stainless steel, nickel-titanium, titanium-molybdenum.Materials & Method: The in vitro study compared the effects of stainless steel, nickel-titanium, and beta-titanium archwires onfrictional forces of three orthodontic bracket systems: ceramic, self-ligating, and stainless steel brackets. All brackets had 0.022”slots, and the wires were 0.019×0.025”. Friction was evaluated in a simulated half-arch fixed appliance on a testing machine. Thestatic and kinetic friction data were analyzed with 1-way analysis of variance (ANOVA) and post-hoc Duncan multiple rangetest.Result: Self-ligating (Damon) brackets generated significantly lower static and kinetic frictional forces than stainless steel (Gemini)and ceramic brackets (Clarity). Among the archwire materials, Beta-titanium showed the maximum amount of frictional forceand stainless steel archwires had the lowest frictional force.Conclusion: The static and kinetic frictional force for stainless steel bracket was lowest in every combination of wire.


2008 ◽  
Vol 78 (6) ◽  
pp. 1089-1094 ◽  
Author(s):  
Tancan Uysal ◽  
Mustafa Ulker ◽  
Sabri Ilhan Ramoglu ◽  
Huseyin Ertas

Abstract Objective: To compare the in vitro microleakage of orthodontic brackets (metal and ceramic) between enamel-adhesive and adhesive-bracket interfaces at the occlusal and gingival sides produced by self-etching primer system with that of conventional acid etching and bonding. Materials and Method: Sixty freshly extracted human mandibular premolar teeth were used in this study. The teeth were separated into four groups of 15 teeth each and received the following treatments: Group 1, 37% phosphoric acid gel + Transbond XT liquid primer + stainless steel bracket; Group 2, Transbond Plus Self-Etching Primer (TSEP) + stainless steel bracket; Group 3, 37% phosphoric acid gel + Transbond XT liquid primer + ceramic bracket; Group 4, TSEP + ceramic bracket. After curing, specimens were further sealed with nail varnish, stained with 0.5% basic fuchsine for 24 hours, sectioned and examined under a stereomicroscope, and scored for microleakage for the enamel-adhesive and bracket-adhesive interfaces from both occlusal and gingival margins. Statistical analyses were performed using Kruskal-Wallis and Mann-Whitney U tests. Results: The gingival sides in all groups exhibited higher microleakage scores compared with those observed in occlusal sides for both adhesive interfaces. Enamel-adhesive interfaces exhibited more microleakage than did the adhesive-bracket interfaces. Brackets bonded with self-etching primer system showed significantly higher microleakage at the enamel-adhesive interface of the gingival side. Conclusions: TSEP causes more microleakage between enamel-adhesive interfaces, which may lead to lower bond strength and/or white-spot lesions.


2012 ◽  
Vol 83 (4) ◽  
pp. 705-711 ◽  
Author(s):  
Da-Young Kang ◽  
Sung-Hwan Choi ◽  
Jung-Yul Cha ◽  
Chung-Ju Hwang

ABSTRACT Objective: To investigate the three-dimensional structural features of three types of mechanically retentive ceramic bracket bases. Materials and Methods: One type of stainless steel (MicroArch, Tomy, Tokyo, Japan) and three types of ceramic maxillary right central incisor brackets—Crystaline MB (Tomy), INVU (TP Orthodontics, La Porte, Ind), and Inspire Ice (Ormco, Glendora, Calif)—were tested to compare and quantitatively analyze differences in the surface features of each ceramic bracket base using scanning electron microscopy (SEM), a three-dimensional (3D) optical surface profiler, and microcomputed tomography (micro-CT). One-way analysis of variance was used to find differences in bracket base surface roughness values and surface areas between groups according to base designs. Tukey's honestly significant differences tests were used for post hoc comparisons. Results: SEM revealed that each bracket exhibited a unique surface texture (MicroArch, double mesh; Crystaline MB, irregular; INVU, single mesh; Inspire Ice, bead ball). With a 3D optical surface profiler, the stainless steel bracket showed significantly higher surface roughness values. Crystaline MB had significantly higher surface roughness values than Inspire Ice. Micro-CT demonstrated that stainless steel brackets showed significantly higher whole and unit bracket base surface areas. Among ceramic brackets, INVU showed significantly higher whole bracket base surface area, and Crystaline MB showed a significantly higher unit bracket base surface area than Inspire Ice. Conclusion: Irregular bracket surface features showed the highest surface roughness values and unit bracket base surface area among ceramic brackets, which contributes to increased mechanically retentive bracket bonding strength.


2013 ◽  
Vol 84 (1) ◽  
pp. 177-183 ◽  
Author(s):  
Sung-Hwan Choi ◽  
Da-Young Kang ◽  
Chung–Ju Hwang

ABSTRACT Objective: To quantitatively analyze the surface roughness of the slot floors of three types of modern plastic brackets and to measure static frictional force during sliding mechanics in vitro. Materials and Methods: Control groups comprised stainless steel brackets and monocrystalline ceramic brackets. Test groups comprised three types of 0.022-in slot, Roth prescription, plastic, maxillary right central incisor brackets. Test groups included glass fiber-reinforced polycarbonate, filler-reinforced polycarbonate, and hybrid polymer with inserted metal slot brackets. The static frictional resistance caused by sliding movements with an archwire (stainless steel) in vitro was quantitatively analyzed. Both scanning electron microscope and three-dimensional optical surface profiling were used. Results: Scanning electron microscope and three-dimensional optical surface profiler revealed that all as-received brackets had irregular slot floor surfaces, and both irregularity and roughness increased after the archwire sliding test. The ceramic brackets in the control group showed significantly lower surface roughness values and higher frictional values during the archwire sliding test compared with the other brackets. The glass or filler-reinforced plastic brackets exhibited significantly higher static frictional values than the metallic slot type brackets (P < .001). The hybrid polymer with inserted metal slot brackets showed relatively lower surface roughness and frictional values compared with the stainless steel control bracket. Conclusion: Glass or filler-reinforced plastic brackets showed higher frictional resistance than metallic slot–type brackets. A plastic bracket with inserted metal slot may be the best choice among plastic brackets for low frictional resistance and to avoid damage from sliding movements of the archwire.


2019 ◽  
Vol 53 (2) ◽  
pp. 101-108 ◽  
Author(s):  
Hina Desai ◽  
Fenil Manishkumar Gandhi ◽  
Kalpesh Patel ◽  
Sarvesh Agrawal

Introduction: The friction generated during orthodontic treatment seems of concern in terms of anchorage and treatment duration. Different ligation methods have been developed to reduce the friction as compared with regular elastic modules. This study aimed to evaluate and to compare static and kinetic friction generated in ceramic brackets with metal slot and epoxy resin-coated stainless steel esthetic wire by using different ligation materials in wet condition (artificial saliva). Materials and Methods: A total of 40 epoxy-coated stainless steel wires and metal slot ceramic brackets were divided into 4 groups of 10 each and ligated using 4 different methods as follows: (1) super slick elastic modules, (2) slide elastic modules, (3) Teflon-coated esthetic stainless steel wire, and (4) regular elastic modules. They were then immersed in artificial saliva for 1 hour before testing their static and kinetic friction using a universal testing machine. Results: The intergroup comparison showed statistically significant differences for static and kinetic friction among all the 4 groups, where group 2 (slide modules) showed the least static as well as kinetic friction as compared with the other 3 groups. Conclusions: (1) Slide modules produced the least amount of friction compared with all other methods of ligation when epoxy resin-coated stainless steel archwire was used in ceramic bracket with 0.22˝ metal slot in wet condition. (2) Super slick modules produced the least friction in comparison with regular elastomeric and Teflon-coated ligature groups but produced greater friction than slide modules. (3) Teflon-coated stainless steel ligature produced the highest friction; however, it was not statistically significant when compared with the conventional elastic ligature. (4) In all clinical situations during the retraction stage, a large amount of friction is created in the buccal segment; hence, it is advisable to use slide modules in the buccal segment to reduce static and kinetic friction.


2020 ◽  
Vol 31 (5) ◽  
pp. 540-547
Author(s):  
Júlio César de Carvalho Alves ◽  
Gilberto Antônio Borges ◽  
Antheunis Versluis ◽  
Carlos José Soares ◽  
Crisnicaw Veríssimo

Abstract 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.


2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Tomasz Ogiński ◽  
Beata Kawala ◽  
Marcin Mikulewicz ◽  
Joanna Antoszewska-Smith

Objective. Clinical comparison of the survival rates between stainless steel and ceramic brackets over a 12-month period. Materials and Methods. The study involved 20 consecutive patients with diagnosed malocclusion that required two-arch fixed appliance treatment. The participants were randomly divided into two 10-member groups. Group 1 was treated with Abzil Agile (3M Unitek) stainless steel brackets; group 2 was treated with Radiance (American Orthodontics) monocrystalline ceramic brackets. All the brackets were bonded by the same operator. Over the next 12 months, all bracket failures were recorded with each appointment. The received data were processed statistically using the Mantel–Cox test, Kaplan–Meier method, and Cox hazard model. Results. A total of 381 brackets were bonded, 195 of which were metallic brackets and 186 were ceramic ones. In the 12-month observation period, there were 14 metal (7.2%) and 2 ceramic bracket (1.1%) failures. The overall failure rate was 4.2% (n = 16). The majority of failures (14 brackets; 87.5%) occurred during the first 6 months of the experiment, 12 (83%) of which were metal brackets and 2 (100%) were ceramic brackets. The statistical analysis revealed significant differences between the groups (p<0.05). Conclusions. Metal brackets demonstrated significantly higher failure rates than ceramic brackets for both 6- and 12-month observation periods (p<0.05). The 6% difference between the brackets is clinically significant as it corresponds to one additional failure within 12 months.


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