Analysis and comparison of different in vitro mechanical tests used to evaluate the ceramic/resin cement adhesive interface's resistance

• Grant number: 18/05660-2
• Support type: Scholarships abroad - Research
• Effective date (Start): September 24, 2018
• Effective date (End): September 23, 2019
• Field of knowledge: Health Sciences - Dentistry - Dental Materials
• Principal researcher: Daniela Micheline dos Santos
• Grantee: Daniela Micheline dos Santos
• Host: Grace M de Souza
• Home Institution: Faculdade de Odontologia (FOA). Universidade Estadual Paulista (UNESP). Campus de Araçatuba. Araçatuba , SP, Brazil
• Research place: University of Toronto (U of T), Canada

Abstract

The strengths of the bonding interfaces between ceramics and resin cements have been verified over time by different in vitro assays. However, there are still doubts as to which method is the most appropriate for evaluating the adhesive interface bond strength and provides reliable results indicative of real-time clinical conditions. The objective of the present study is to evaluate the strengths of the adhesive interfaces formed by ceramics and cements by means of different models of in vitro tests: microtensile, tensile, microshear, shear, micropush-out, push-out, and fracture toughness. The different in vitro assay models will be simulated in silico using finite element analysis (FEA) to correlate the values obtained for each proposed in vitro assay with the data obtained from FEA to propose the most appropriate mechanical assay. For this, samples with different formats will be prepared according to the parameters of each proposed trial, and distributed in seven groups. The surfaces of the ceramic samples will be conditioned with hydrofluoric acid, followed by ultrasonic washing, and then silanized. Composite resin samples will be cemented on the ceramic surfaces using dual curing resin cement. The microtensile, tensile, microshear, shear, micropush-out, push-out, and fracture toughness tests will be performed and the bond strengths of the adhesive interfaces measured. The failure modes of the samples used in each test will be evaluated and quantified. The distribution of each proposed in vitro assay will be analyzed by FEA. The data obtained will be incorporated in the normal curve of the adhesion test, with the appropriate statistical test being applied for the comparison of mean values. Correlation tests will be applied between the bond strength values obtained for each in vitro test and the stress data obtained by finite element analysis.