RESUMO
O objetivo do presente trabalho foi avaliar, por meio de teste de compressão, a resistência à fratura de infraestruturas metálicas de próteses totais implantossuportadas do tipo protocolo de Branemark em função de diferentes designs (comprimentos e altura) do cantilever, bem como espessura do conector distal. Foram confeccionadas 39 infraestruturas (barras) em liga de CoCr agrupadas de acordo com o comprimento do cantilever (cc) (12mm, 19mm e 26mm), altura do cantilever (hc) (3,2 mm, 4mm) e espessura do conector distal (ec) (0,4mm, 1,5mm e 2mm). Os grupo foram divididos em Controle (cc 12mm; hc 4mm; ec 1,5),Grupo 1 (cc 12mm; hc 4mm; ec 0,4mm), Grupo 2(cc 12mm; hc 3,2mm; ec 0,4mm), Grupo 3 (cc 12mm; hc 3,2mm; ec 1,5mm), Grupo 4 (cc 19mm; hc 4mm; ec 1,5mm), Grupo 5 (cc 19mm; hc 4mm; ec 0,4mm), Grupo 6 (cc 19mm; hc 3,2mm; ec 1,5mm), Grupo 7 (cc 19mm; hc 3,2mm; ec 0,4mm), Grupo 8 (cc 26mm; hc 4mm; ec 1,5mm), Grupo 9 (cc 26mm; hc 4mm; ec 0,4mm), Grupo 10 (cc 26mm; hc 3,2mm; ec 1,5mm) e Grupo 11 (cc 26mm; hc 3,2mm; ec 0,4mm). Todos os espécimes foram submetidos a ensaio de compressão em uma maquina de ensaio universal com célula de carga de 5000N e velocidade constante de 0,5mm/min. Os dados obtidos foram submetidos a analise estatística ANOVA a três critérios, seguido pelo teste de Tukey, com nível se significância de 5% (p<0,05). Foi observada uma diferença significante na diminuição de resistência a compressão com o aumento do comprimento do cantilever, um aumento significante de resistência nos grupos com altura de cantileveres maiores. Foi concluído que quanto menor o comprimento e maior a altura do cantilever, maior será a resistência. Já a espessura do conector influenciou a resistência, porém sem uniformidade(AU)
The aim of this study was to evaluate, through compression test, the fracture strength of metal infrastructure dentures implant of the Branemark protocol type for different designs (length and height) of the cantilever and thickness of the connector distal. 39 were prepared infrastructure (bar) pooled CoCr alloy according to the length of the cantilever (cc) (12mm, 19mm and 26mm), the cantilever height (hc) (3.2mm, 4mm) thick and the distal connector ( c) (0.4mm, 1.5mm and 2mm). The group were divided into control (cc 12mm; hc 4mm and c 1.5), Group 1 (cc 12mm; hc 4mm, 0.4mm c), Group 2 (cc 12 mm; hc 3.2mm, 0.4mm and c) Group 3 (cc 12 mm; hc 3.2mm, 1.5mm c), Group 4 (cc 19mm; hc 4mm, 1.5mm c), Group 5 (cc 19mm; hc 4mm, 0.4mm c), Group 6 (cc 19mm; hc 3.2mm, 1.5mm c), Group 7 (cc 19mm; hc 3.2mm, 0.4mm c), Group 8 (cc 26mm; hc 4mm, 1.5mm c), Group 9 ( cc 26mm; hc 4mm, 0.4mm c) Group 10 (cc 26mm; hc 3.2mm, 1.5mm c) and Group 11 (cc 26mm; hc 3.2mm, 0.4mm and c). All specimens were subjected to compression test in a universal testing machine with 5000N load cell and constant speed of 0.5 mm / min. Data were analyzed by ANOVA statistical analysis three criteria, followed by Tukey test, with significance level was 5% (p <0.05). a significant difference in the decrease of resistance to compression with increasing length of the cantilever, a significant increase in resistance groups with height greater cantilevers was observed. It was concluded smaller length and greater height of cantielver, the greater the resistance. Already the connector thickness influenced the resistance, but without uniformity(AU)
Assuntos
Ligas de Cromo , Prótese Dentária Fixada por ImplanteRESUMO
STATEMENT OF PROBLEM: Dental magnetic materials have been applied to removable prosthetic appliances, maxillofacial prostheses, obturator and dental implant but they still have some problems such as low corrosion resistance in oral environments. PURPOSE: To increase the corrosion resistance of dental magnetic materials, surfaces of Sm-Co and Nd-Fe-B based magnetic materials were plated with TiN and sealed with stainless steels. MATERIALS AND METHODS: Surfaces of Sm-Co and Nd-Fe-B based magnetic materials were plated with TiN and sealed with stainless steels, and then three kinds of electrochemical corrosion test were performed in 0.9% NaCl solution; potentiodynamic, potentiostatic, and electrochemical impedance test. From this study, corrosion behavior, amount of elements released, mean average surface roughness values, the changing of retention force, and magnetic force values were measured comparing with control group of non-coated magnetic materials. RESULTS: The values of surface roughness of TiN coated Sm-Co and TiN coated Nd-Fe-B based magnetic materials were lower than those of non coated Sm-Co and Nd-Fe-B alloy. From results of potentiodynamic test, the passive current density of TiN coated Sm-Co alloy were smaller than those of TiN coated Nd-Fe-B alloy and non coated alloys in 0.9% NaCl solution. From results of potentiostatic and electrochemical impedance test, the surface stability of the TiN coated Sm-Co alloy was more drastically increased than that of the TiN coated Nd-Fe-B alloy and non-coated alloy. The retention and magnetic force after and before corrosion test did not change in the case of TiN coated magnetic alloy sealed with stainless steel. CONCLUSION: It is considered that the corrosion problem and improvement for surface stability of dental magnetic materials could be solved by ion plating with TiN on the surface of dental magnetic materials and by sealing with stainless steels.