Influence of cusp inclination on the resistance of screw-retained and cement-retained implant-supported metal-ceramic crowns

Abstract

Several factors are reported in the literature because they are related to the fracture resistance of prostheses implant-supported, however, the influence of one more factor should be considered: the inclination of the cusps. The aim of this study is to evaluate the influence of cusp inclination on fracture resistance of metal-ceramic crowns implant-supported. For this, six experimental groups (n = 10) will be tested: (1) metal-ceramic prosthesis (MC) cemented with cusp inclination standard (33°) and (2) with reduced cusps inclination (20°). (3) MC prosthesis screwed with the access hole and the screw not restored and cusp inclination standard (4) with cusp inclination reduced, (5) metal-ceramic prosthesis screwed with the screw access restored and cusp inclination standard and (6) with reduced cusp inclination. For the manufacture of the samples a metal matrix containing an analog implant external hexagon diameters of 5.0 mm (Biomet 3i, West Palm Beach, FL) and a cylinder UCLA (Biomet 3i, West Palm Beach, FL) plastic are used. Indexes of silicone to elements with standard and reduced cusps inclination will be used to standardize the final anatomy crowns and ceramic thickness. The mechanical test is performed and the data will be stored in specific software (TESC) of universal testing machine EMIC DL2000. The force shall be applied until there is a fracture of the ceramic and the average values are recorded in Newton (N). All data will be analyzed using ANOVA and Tukey's test for multiple comparisons (p <0.05). (AU)