Revista de Odontologia da UNESP
https://revodontolunesp.com.br/article/doi/10.1590/1807-2577.04819
Revista de Odontologia da UNESP
Original Article

Fracture strength of monocrystalline and polycrystalline ceramic brackets during archwire torque

Resistencia à fratura de braquetes cerâmicos

Társio Caleb Bernardon KIELING; Lourenço CORRER-SOBRINHO; Ana Paula Terossi de GODOI; Carolina Carmo de MENEZES; Giovana Cherubini VENEZIAN; Ana Rosa COSTA

Downloads: 0
Views: 15

Abstract

Abstract: Introduction: In recent years, there has been an increasing demand for esthetic treatments, especially among orthodontic patients.

Objective: This study determined the fracture strength of monocrystalline and polycrystalline ceramic brackets of different manufacturers during archwire torque.

Material and method: Sixty ceramic brackets (Roth, right upper central incisors, 0.022 x 0.028-inch slot) were allocated into two groups (30 specimens per group) according to the type of ceramics: monocrystalline and polycrystalline. Subsequently, the groups were divided into three subgroups (n = 10) according to the manufacturer: Orthometric, Eurodonto and Ortho Technology. Sixty PVC cylinders were filled with chemically activated acrylic resin (CAAR), the brackets were fixed with CAAR onto the cylinder surface and the excess material was used to partially cover the base of the bracket. After 24h, the U-shaped wire base (0.019 x 0.025 inches; 6 mm height and width) was inserted into the bracket slot and fixed thereon with a stainless-steel wire. Vertical folds were made at the ends of the “U” to support the universal test machine chisel. The fracture strength test was performed at a speed of 1.0 mm/min until fracture into a universal test machine (Instron). The data were recorded, transformed into g.mm and submitted to two-way ANOVA followed by Tukey’s post-hoc test (SAS Institute Inc., Cary, NC, USA, version 9.3) (α=5%).

Result: Monocrystalline brackets showed a higher fracture strength than polycrystalline brackets, regardless of the manufacturer (p<0.05). The highest fracture strength values were observed in Ortho Technology and Orthometric brackets, with no significant difference between them (p>0.05).

Conclusion: Monocrystalline ceramic brackets have a higher fracture strength than polycrystalline brackets, with significant manufacturer-dependent differences.

Keywords

Ceramic brackets, fracture strength, torsion, torque

Resumo

Resumo: Introdução: A demanda por tratamentos estéticos tem crescido nos últimos anos, sendo cada vez mais forte a preocupação com a estética por parte dos pacientes que buscam o tratamento ortodôntico.

Objetivo: Este estudo avaliou a resistência à fratura de bráquetes cerâmicos monocristalinos e policristalinos de diferentes fabricantes quando submetidos ao torque do fio.

Material e método: Sessenta bráquetes cerâmicos (Roth, incisivos centrais superiores direito, canaleta 0,022 x 0,028 polegadas) foram divididos em 2 grupos (30 espécimes por grupo) de acordo com o tipo da cerâmica: monocristalina e policristalina. Posteriomente estes grupos foram divididos em 3 sub-grupos (n=10) de acordo com o fabricante: Orthometric, Eurodonto e Ortho Technology. Segmentos de fio de aço inoxidável retangular (0,019 x 0,025 polegadas) foram dobrados em forma de “U”, sendo que a base do “U” foi inserida na canaleta do bráquete e fixado com fio de amarilho em aço inoxidável (0,008mm). Nas extremidades do “U” foram realizadas dobras verticais para servir de apoio para o cinzel da máquina de ensaio universal Instron. O ensaio de resistência à fratura foi realizado à velocidade de 1,0 mm/min até ocorrer a fratura. Os dados foram registrados, transformados em g.mm e submetidos à ANOVA dois fatores e ao teste de Tukey (SAS Institute Inc., Cary, NC, USA, version 9.3) (α=5%).

Resultado: Os bráquetes monocristalinos apresentaram maior resistência à fratura em relação aos policristalinos, independente do fabricante (p<0,05). Os maiores valores de resistência à fratura foram obtidos com os bráquetes da Ortho Technology e Orthometric, os quais não diferiram estatisticamente entre si (p>0,05).

Conclusão: Bráquetes monocristalinos possuem maior resistência à fratura em relação aos policristalinos com diferenças na resistência à fratura entre os diferentes fabricantes.
 

Palavras-chave

Bráquetes cerâmicos, resistência à fratura, torção, torque

References

Rosvall MD, Fields HW, Ziuchkovski J, Rosenstiel SF, Johnston WM. Attractiveness, acceptability, and value of orthodontic appliances. Am J Orthod Dentofacial Orthop. 2009 Mar;135(3):276.e1-12, discussion 276-7. http://dx.doi.org/10.1016/j.ajodo.2008.07.011. PMid:19268820.

Newman GV. Adhesion and orthodontic plastic attachments. Am J Orthod. 1969 Dec;56(6):573-88. http://dx.doi.org/10.1016/0002-9416(69)90193-6. PMid:5260045.

Alkire RG, Bagby MD, Gladwin MA, Kim H. Torsional creep of polycarbonate orthodontic brackets. Dent Mater. 1997 Jan;13(1):2-6. http://dx.doi.org/10.1016/S0109-5641(97)80001-2. PMid:9467316.

Araújo MD, Grande RM, Yoshimura HN. Microestrutura e propriedades mecânicas de bráquetes cerâmicos. Journal of Biodentistry and Biomaterials. 2013;2:11-26.

Jena AK, Duggal R, Mehrotra AK. Physical properties and clinical characteristics of ceramic brackets: a comprehensive review. Trends Biomater Artif Organs. 2007 Jan;20(2):101-15.

Babaji P, Shivaprakash S, Dmello K, Kamble SS, Ajith S, Gowda AR. An in vitro comparison of resistance to second and third order archwire activations of three different varieties of esthetic brackets. Indian J Dent Res. 2013 Nov-Dec;24(6):701-7. http://dx.doi.org/10.4103/0970-9290.127615. PMid:24552930.

Manhães FR, Divino R, Lucato AS, Vedovello SAS, Correa CA, Valdrighi HC. Fracture strength of ceramic brackets submitted to arch wire torsional strain. Braz J Oral Sci. 2011 Jul/Sep;10(3):180-3.

Lopes H Fo, Maia LE, Araújo MV, Ruellas AC. Influence of optical properties of esthetic brackets (color, translucence, and fluorescence) on visual perception. Am J Orthod Dentofacial Orthop. 2012 Apr;141(4):460-7. http://dx.doi.org/10.1016/j.ajodo.2011.10.026. PMid:22464528.

Sobreira CR, Loriato LD, Oliveira DD. Bráquetes estéticos: características e comportamento clínico. Rev Clin Ortodon Dental Press. 2007 Fev-Mar;6(1):94-102.

Lacarbonara M, Accivile E, Abed MR, Dinoi MT, Monaco A, Marzo G, et al. Variable Torque Prescription: State of Art. Open Dent J. 2015 Jan;9(1):60-4. http://dx.doi.org/10.2174/1874210601509010060. PMid:25674173.

Johnson E. Selecting custom torque prescriptions for the straight-wire appliance. Am J Orthod Dentofacial Orthop. 2013 Apr;143(4 Suppl):S161-7. http://dx.doi.org/10.1016/j.ajodo.2012.09.003. PMid:23540633.

Streva AM, Cotrim-Ferreira FA, Garib DG, Carvalho PE. Are torque values of preadjusted brackets precise? J Appl Oral Sci. 2011 Aug;19(4):313-7. http://dx.doi.org/10.1590/S1678-77572011005000003. PMid:21956587.

Arreghini A, Lombardo L, Mollica F, Siciliani G. Torque expression capacity of 0.018 and 0.022 bracket slots by changing archwire material and cross section. Prog Orthod. 2014 Sep;15(1):53. http://dx.doi.org/10.1186/s40510-014-0053-x. PMid:25329505.

Alrejaye N, Pober R, Giordano R 2nd. Torsional strength of computer-aided design/computer-aided manufacturing–fabricated esthetic orthodontic brackets. Angle Orthod. 2017 Jan;87(1):125-30. http://dx.doi.org/10.2319/040416-267.1. PMid:27403781.

Vhanbatte RS, Uddanwadiker RV, Patil P. Evaluation of torsional strength of ceramic brackets produced by arch wire twisting moment. International Journal on Mechanical Engineering and Robotics. 2014;2(4):33-7.

Nishio C, Mendes AM, Almeida MA, Tanaka E, Tanne K, Elias CN. Evaluation of esthetic brackets’ resistance to torsional forces from the archwire. Am J Orthod Dentofacial Orthop. 2009 Jan;135(1):42-8. http://dx.doi.org/10.1016/j.ajodo.2007.04.036. PMid:19121499.

Archambault A, Lacoursiere R, Badawi H, Major PW, Carey J, Flores-Mir C. Torque expression in stainless steel orthodontic brackets. A systematic review. Angle Orthod. 2010 Jan;80(1):201-10. http://dx.doi.org/10.2319/080508-352.1. PMid:19852662.

Major TW, Carey JP, Nobes DS, Heo G, Major PW. Mechanical effects of third-order movement in self-ligated brackets by the measurement of torque expression. Am J Orthod Dentofacial Orthop. 2011 Jan;139(1):e31-44. http://dx.doi.org/10.1016/j.ajodo.2010.04.029. PMid:21195255.

Lohbauer U, Amberger G, Quinn GD, Scherrer SS. Fractographic analysis of a dental zirconia framework: a case study on design issues. J Mech Behav Biomed Mater. 2010 Nov;3(8):623-9. http://dx.doi.org/10.1016/j.jmbbm.2010.07.004. PMid:20826369.

Aknin PC, Nanda RS, Duncanson MG Jr, Currier GF, Sinha PK. Fracture strength of ceramic brackets during arch wire torsion. Am J Orthod Dentofacial Orthop. 1996 Jan;109(1):22-7. http://dx.doi.org/10.1016/S0889-5406(96)70159-2. PMid:8540476.

Ghafari J. Problems associated with ceramic brackets suggest limiting use to selected teeth. Angle Orthod. 1992;62(2):145-52. PMid:1626749.

Swartz ML. Ceramic brackets. J Clin Orthod. 1988 Feb;22(2):82-8. PMid:3075208.

Holt MH, Nanda RS, Duncanson MG Jr. Fracture resistance on ceramic brackets during arch wire torsion. Am J Orthod Dentofacial Orthop. 1991 Apr;99(4):287-93. http://dx.doi.org/10.1016/0889-5406(91)70010-T. PMid:2008887.

Nikolai RJ. Bioengineering analysis of orthodontic mechanics: Philadelphia: Lea & Febiger; 1985. p. 299-305.
 

5d9397fa0e88259e18dd775c rou Articles
Links & Downloads

Rev. odontol. UNESP

Share this page
Page Sections