Analysis of the lithium disilicate ceramic/cement after different surface treatments and thermocycling

• Grant number: 18/02419-2
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): March 01, 2018
• Effective date (End): February 28, 2019
• Field of knowledge: Health Sciences - Dentistry - Dental Materials
• Principal Investigator: Marcelo Coelho Goiato
• Grantee: Lucas Tavares Piacenza
• Host Institution: Faculdade de Odontologia (FOA). Universidade Estadual Paulista (UNESP). Campus de Araçatuba. Araçatuba , SP, Brazil

Abstract

The search for aesthetic restorations through ceramic fragments has been increasing. Among the types of ceramics, vitreous ceramic pressed systems are well indicated, such as those reinforced with lithium disilicate particles. In order to achieve the clinical success and longevity of these restorations, the clinical procedure of adhesive cementation is of paramount importance. Thus, the present study aims to compare the surface treatment of lithium disilicate ceramics performed with two different types of low temperature plasma (NTP1 + S: PBT 1 + silane treatment; NTP2 + S: PBT 2 treatment + silane) with the conventional method (HF + S: hydrofluoric acid 5% + silane), before and after thermocycling, evaluating the bond strength values between the resin cement and the ceramic and the failure mode. For this, sixty vitro-ceramic samples of lithium disilicate will be made. Mechanical polishing of all samples with sequential metallographic sanding (# 320, # 400, # 600) will be performed. After this procedure, the samples will be randomly distributed in groups (n = 10), with and without thermocycling, where each group will receive a type of surface treatment (NTP1 + S: treatment with PBT 1 + silane; PBT 2 + silane; HF + S: 5% hydrofluoric acid + silane). And all the samples will be submitted to the tests of shear strength and analysis of the mode of union. The thermocycling process will be carried out in a thermocycler where the samples will be immersed in distilled water and submitted to alternating baths of 30 seconds at 5 ± 1 ° C and 55 ± 1 ° C, totaling 5000 cycles. The union strength values were submitted to a one-factor analysis of variance (ANOVA) and Tukey test with significance of 5% (± = 0.05) (SPSS version 20.0 - Statistical Package for the Social Sciences, IBM Corp.). The relationship between the variables surface treatment and failure mode after the union strength test was analyzed using the chi-square test with significance of 5% (± = 0.05). (AU)