Biomechanical behavior and survival of implant-supported hybrid ceramic crowns manufactured by different techniques

Author(s)

João Paulo Mendes Tribst

• Document type: Doctoral Thesis
• Press: São José dos Campos. 2020-08-19.
• Institution: Universidade Estadual Paulista (Unesp). Instituto de Ciência e Tecnologia. São José dos Campos
• Defense date: 2020-07-24
• Advisor: Marco Antonio Bottino

Abstract

The present study aimed to investigate the survival probability and the stress distribution of a polymer infiltrate ceramic restorations cemented on a chairside titanium‐base manufactured using different techniques. Seventy-five implant-supported crowns were divided according to the manufacturing technique using a chairside titanium‐base: CME - Two-piece prosthetic solution composed by a crown cemented on the hybrid abutment; MC - One-piece prosthetic solution composed by a crown direct cemented on a titanium base; and MP - One-piece prosthetic solution composed by a crown cemented on a Tibase with screw access hole. All crowns were staircase fatigued (load step of 50 N in each 20,000 cycles until 1200 N and 350,000 cycles). The failed crowns were inspected under scanning electron microscopy. And the survival probability using Log-Rank and Willcoxon tests. One threedimensional geometry from each group were modeled and analyzed using the finite element method. Results in total deformation, von-Misses stress, maximum principal stress and microstrain were requested under 900 N axial load. Log-Rank (p = 0.17) and Willcoxon (p = 0.11) revealed similar survival probability between the techniques at 300 and 900 N. Regardless of the similar survival between CME and MC, MP showed superior characteristic strength and less data variation. Higher stress concentration was observed in the emergence profile of the crown regardless the group design. Fractography analysis allowed to identify that the crack propagation direction occurred from cervical to occlusal. It is possible to conclude that the survival of an implant-supported restoration with polymer infiltrated ceramic network is not influence by the technique used to make it; and that the emergence profile of the prosthetic crown must always be evaluated due to the great incidence of failures in this area. (AU)

• FAPESP's process: 17/09104-4 - Biomechanical behavior and survival of implant-supported hybrid ceramic crowns manufactured by different techniques
• Grantee: João Paulo Mendes Tribst
• Support Opportunities: Scholarships in Brazil - Doctorate