Braquetes cerâmicos impressos 3D: Ensaio biomecâmico de resistência ao cisalhamento
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Data
2022-08-24
Autores
Souza, Larissa Amaral de
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Universidade Estadual Paulista (Unesp)
Resumo
Avaliar, por meio de um ensaio biomecânico, a resistência ao cisalhamento dos braquetes cerâmicos confeccionados em impressora 3D. Metodologia: Foram testados três tipos distintos de braquetes: Braquetes cerâmicos LightForce Clear® - 3D - LFO System®, (Cambridge, Massac – EUA) (n=10), neste trabalho denominado como grupo LFC, braquetes cerâmicos LightForceWhite® - 3D – LFO System® - (Cambridge, Massac – EUA) (n=10), neste trabalho denominado como grupo LFW, e braquetes cerâmicos Clarity® da 3M® – UNITEK (Monrovia, Califórnia – EUA) (n=10), neste trabalho denominado como grupo C. Os braquetes do grupo C foram utilizados como controle. Foram colados em esmalte bovino, fixados em suportes para realização de teste em máquina universal de cisalhamento com acessórios de garra para suporte. Foi aplicada uma carga inciso-apical sobre o braquete com célula de carga de 50kgf e velocidade de deslocamento de 1 mm/min até o surgimento de falha na interface dente-braquete. O valor de força de pico registrado foi considerado como a força de cisalhamento (N) necessária para romper a união dente-suporte. A resistência ao cisalhamento foi obtida, em MPa, dividindo a carga de ruptura, em Newtons, pela área da superfície em mm2 . A análise da fratura foi feita com aumento de 15x utilizando microscópio estereoscópio binocular Discovery V20 - Carl Zeiss® (Oberkochen, Alemanha). Análise estatística: Foi realizada análise de variância utilizando teste ANOVA. O teste Tukey foi aplicado para determinar quaisquer diferenças significativas para valores de desempenho entre os grupos. Resultados: Os valores médios e desvio padrão obtidos no ensaio de resistência ao cisalhamento (Mpa) nos três grupos de braquetes foram: 12,00 ± 5,26 para C, 16,45 ± 3,57 para LFC e 14,58 ± 5,04 para LFW. Não houve diferença estatística na resistência ao cisalhamento de nenhum dos grupos testados, os grupos LFC e LFW se mostraram semelhantes ao grupo C (controle). Conclusão: Os braquetes cerâmicos confeccionados em impressora 3D apresentaram resultados satisfatórios de SBS quando comparados ao grupo controle. Todos os grupos apresentaram fratura adesiva semelhante demonstrando boas retenções em suas bases.
To evaluate the shear strength of ceramic brackets produced in a 3D printer by a biomechanical test. Methodology: Three different types of brackets were tested: LightForce Clear® ceramic brackets - 3D - LFO System®, (Cambridge, Massac - USA) (n=10), referred to as the LFC group in this paper, LightForceWhite® ceramic brackets - 3D - LFO System® - (Cambridge, Massac - USA) (n=10), referred to as the LFW group in this paper, and Clarity® ceramic brackets from 3M® - UNITEK (Monrovia, California - USA) (n=10), referred to as Group C in this paper. Group C brackets were used as controls. They were bonded to bovine enamel and attached to holders for testing in a universal machine with shear claw accessories. The bracket was loaded with a load cell of 50 kgf and a displacement speed of 1 mm/min until failure occurred at the tooth-bracket interface. The peak force recorded was considered to be the shear force (N) required to break the tooth-bracket junction. The shear strength in MPa was determined by dividing the fracture load in Newtons by the area in mm2. Fracture analysis was performed at 15x magnification using a Discovery V20 binocular stereoscopic microscope - Carl Zeiss® (Oberkochen, Germany). Statistical analysis: Analysis of variance was performed using ANOVA test. The Tukey test was applied to determine any significant differences for performance values between groups. Results: The mean values and standard deviation obtained in the shear strength test (Mpa) in the three groups of brackets were: 12.00 ± 5.26 for C, 16.45 ± 3.57 for LFC and 14.58 ± 5.04 for LFW. There was no statistical difference in the shear strength of any of the groups tested, the LFC and LFW groups were similar to group C (control). Conclusion: Ceramic brackets printed on a 3D printer showed satisfactory SBS results when compared to the control group. All groups presented adhesive fracture demonstrating good retention at their bases.
To evaluate the shear strength of ceramic brackets produced in a 3D printer by a biomechanical test. Methodology: Three different types of brackets were tested: LightForce Clear® ceramic brackets - 3D - LFO System®, (Cambridge, Massac - USA) (n=10), referred to as the LFC group in this paper, LightForceWhite® ceramic brackets - 3D - LFO System® - (Cambridge, Massac - USA) (n=10), referred to as the LFW group in this paper, and Clarity® ceramic brackets from 3M® - UNITEK (Monrovia, California - USA) (n=10), referred to as Group C in this paper. Group C brackets were used as controls. They were bonded to bovine enamel and attached to holders for testing in a universal machine with shear claw accessories. The bracket was loaded with a load cell of 50 kgf and a displacement speed of 1 mm/min until failure occurred at the tooth-bracket interface. The peak force recorded was considered to be the shear force (N) required to break the tooth-bracket junction. The shear strength in MPa was determined by dividing the fracture load in Newtons by the area in mm2. Fracture analysis was performed at 15x magnification using a Discovery V20 binocular stereoscopic microscope - Carl Zeiss® (Oberkochen, Germany). Statistical analysis: Analysis of variance was performed using ANOVA test. The Tukey test was applied to determine any significant differences for performance values between groups. Results: The mean values and standard deviation obtained in the shear strength test (Mpa) in the three groups of brackets were: 12.00 ± 5.26 for C, 16.45 ± 3.57 for LFC and 14.58 ± 5.04 for LFW. There was no statistical difference in the shear strength of any of the groups tested, the LFC and LFW groups were similar to group C (control). Conclusion: Ceramic brackets printed on a 3D printer showed satisfactory SBS results when compared to the control group. All groups presented adhesive fracture demonstrating good retention at their bases.
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Palavras-chave
braquetes ortodônticos, impressão tridimensional, resistência ao cisalhamento, orthodontic brackets, three-dimensional printing, shear bond strength