Effect of alumina whiskers incorporation on the mechanical and optical behavior of glass ceramics.

• Grant number: 24/22990-7
• Support Opportunities: Regular Research Grants
• Start date: September 01, 2025
• End date: August 31, 2028
• Field of knowledge: Health Sciences - Dentistry - Dental Materials
• Principal Investigator: Camila da Silva Rodrigues
• Grantee: Camila da Silva Rodrigues
• Host Institution: Instituto de Ciência e Tecnologia (ICT). Universidade Estadual Paulista (UNESP). Campus de São José dos Campos. São José dos Campos , SP, Brazil
• Associated researchers: Alexandre Luiz Souto Borges ; Renata Marques de Melo Marinho ; Tiago Moreira Bastos Campos

Abstract

Feldspathic and leucite-reinforced glass ceramics are among the least mechanically resistant ceramics and are also less commonly known and used by dentists. In this context, the development of alternative treatments to enhance mechanical reinforcement may increase their reliability and, consequently, the longevity of restorations. Therefore, this study aims to analyze the mechanical and optical effects of incorporating alumina whiskers into the glaze layer applied to monolithic specimens of feldspathic and leucite-reinforced glass ceramics. In the second phase, the mechanical, optical, adhesive effects of incorporating alumina whiskers into the composition of feldspathic ceramics will be evaluated. In the first phase, discs-shaped specimens will be prepared from blocks of a feldspathic ceramic and a leucite-reinforced glass ceramic. Specimens of each material will be divided into four groups according to the surface treatment: no glaze application, glaze as recommended by the manufacturer, glaze with 5w% Al2O3 whiskers, or glaze with 10w% Al2O3 whiskers. In the second phase, specimens will be fabricated from a feldspathic ceramic powder, divided into the following groups: no addition of Al2O3, 5w% addition of Al2O3 whiskers, or 10w% addition of Al2O3 whiskers. These groups will be further subdivided based on whether or not a commercial glaze layer is applied. In both phases, biaxial flexural strength tests, fractographic, roughness (Ra and Rz), translucency (TP00), color change (¿E00), hardness, toughness, bond strength to resin cement, and X-ray diffraction analyzes will be performed. A third phase will be conducted including the experimental groups achieving the best results in phases 1 and 2. Cyclic fatigue tests and finite element analysis to evaluate stress distribution and maximum principal stresses will be performed. (AU)