In vitro biomechanical analysis of customized and not customized aesthetic zircônia abutment

Author(s)

Izabela Cristina Mauricio Moris

• Document type: Doctoral Thesis
• Press: Ribeirão Preto.
• Institution: Universidade de São Paulo (USP). Faculdade de Odontologia de Ribeirão Preto (PCARP/BC)
• Defense date: 2015-05-19

Examining board members

Renata Cristina Silveira Rodrigues Ferracioli; Gelson Luiz Adabo; Wirley Gonçalves Assunção; Ricardo Faria Ribeiro; Rodrigo Tiossi

• Advisor: Renata Cristina Silveira Rodrigues Ferracioli

Abstract

Now implants have been a viable option of treatment for reaching an adequate oral rehabilitation, once the aesthetic have become a factor of great importance in Dentistry. The zirconia abutments have appeared as a good alternative to fill the aesthetic factor that is not present in the metallic abutments. The aim of the present study was to evaluate the fracture strength of customized and not customized zirconia abutments and the effect of thermomechanical cycling in the marginal fit, torque loss and cementation resistance of these abutments. For fracture strength evaluation, 18 morse taper implants were used and divided into three groups: GZr: 6 sets of implants/zirconia abutments; GZrp: 6 sets of implants/customized zirconia abutments and GTi: 6 sets of implants/titanium abutments (control). The sets were submitted to compressive oblique loading in universal testing machine, with a load cell of 500kgf and 0.5mm/min speed, in a 30 degree angulation. For evaluation of the thermomechanical cycling effect, 24 morse taper implants were used and divided into three groups: GZr: 8 sets implants/zirconia abutments; GZrp: 8 sets implants/customized zirconia abutments and GTi: 8 sets implants/titanium abutments (control). The abutments were installed with the torque recommended by the manufacturer (15Ncm). Ceramic crowns were made for all groups. The marginal fit of crowns was evaluated before and after thermomechanical cycling and the cementation resistance of crowns was evaluated after thermomechanical cycling by tensile strength test. The sets were submitted to 1,000,000 mechanical cycles and 8,400 thermal cycles. The fracture strength data were statistically analyzed by ANOVA and Tukey\'s test. The GZrp group presented fracture strength statistically greater than GZr (p=.009) and GZr was similar to GTi. Marginal fit and torque loss data were analyzed by mixed linear model. In the marginal fit, significant difference was noted between GZrp and GTi (after: p=.010), but no difference was noted in the group at different times (before and after thermomechanical cycling).For torque loss, no significant difference was noted before and after thermomechanical cycling in the groups, but significant difference was noted between Gzrp and GTi after thermomechanical cycling. Cementation resistance of crowns was analyzed by ANOVA and no significant difference was noted among the groups. Thus, it was concluded that customization of zirconia abutments does not affect their mechanical properties, and the behavior of zirconia abutments is similar to titanium ones, enabling its clinical use. (AU)

• FAPESP's process: 12/00407-0 - Analysis of misfit and torque loss after thermomechanical cycling and fracture resistance of zirconia abutments for morse cone implants.
• Grantee: IZABELA CRISTINA MAURICIO MORIS RIVERA
• Support Opportunities: Scholarships in Brazil - Doctorate