Optical properties and fracture strength of monolithic zirconia and lithium disilicate with different thickness

• Grant number: 17/16927-7
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: December 01, 2017
• End date: November 30, 2018
• Field of knowledge: Health Sciences - Dentistry - Dental Materials
• Principal Investigator: Gelson Luis Adabo
• Grantee: Nicole Grigolatto Olenscki
• Host Institution: Faculdade de Odontologia (FOAr). Universidade Estadual Paulista (UNESP). Campus de Araraquara. Araraquara , SP, Brazil

Abstract

The chipping of veneer porcelain is a recurrent problem in polycrystalline zirconia-based ceramic restorations. To eliminate the necessity of porcelain veneering, high translucency zirconia has been introduced on the market, which as well as lithium disilicate, were developed for monolithic indication. However, the mechanical behavior of these materials at minimal thickness is still uncertain, as well as the influence of the thickness and substrate color on the final color of these restorations. The aims of this study are: (1) evaluate the effect of different thicknesses of two "translucent" zirconia (Prettau and Prettau Anterior) and a lithium disilicate (IPS e.max CAD) by fracture load static test; and (2) evaluate the effect of different substrate color and specimens with different thicknesses on color differences (”E). Specimens with 12 mm of diameter and thicknesses of 0.5 mm, 1 mm and 1.5 mm will be cemented with self-adhesive cement RelyX Ultimate on epoxy resin specimens (12 mm of diameter and 3 mm of thickness). The fracture load test (n=30) will be performed in a universal testing machine MTS 810, with 4 mm diameter tungsten spherical indenter at the center of the specimen and the fractures will be evaluated. Weibull analyzes will be performed to obtain structural reliability and probability of failure. The color differences (”E) will be performed by spectrophotometry to obtain CIELAB color parameters (n=10). The materials, with different thicknesses, will be combined with composite resin substrates in the A1, A3 and C4 colors. The color differences (”E) will be calculated comparing each substrate color of composite resin in the three selected colors. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

LONGHINI, D.; ROCHA, C. O. M.; DE OLIVEIRA, L. T.; OLENSCKI, N. G.; BONFANTE, E. A.; ADABO, G. L.. Mechanical Behavior of Ceramic Monolithic Systems With Different Thicknesses. Operative Dentistry, v. 44, n. 5, p. E244-E253, SEP-OCT 2019. (16/09640-0, 17/16927-7, 17/08411-0)