Effect of surface treatments on flexural strength of lithium disilicate ceramics

• Grant number: 12/16009-4
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: December 01, 2012
• End date: November 30, 2014
• Field of knowledge: Health Sciences - Dentistry - Dental Materials
• Principal Investigator: Estevão Tomomitsu Kimpara
• Grantee: Natália Rivoli Rossi
• Host Institution: Instituto de Ciência e Tecnologia (ICT). Universidade Estadual Paulista (UNESP). Campus de São José dos Campos. São José dos Campos , SP, Brazil

Abstract

Nowadays, dental ceramics have been proposed and used without metal reinforcement. This development is mainly due to favorable properties and improved, but still have some inadequacies inherent in the material. Within these innovations, exists the reinforced ceramics by oxides of lithium disilicate, which are available on the market with commercial name of IPS e.max CAD, that used the CAD / CAM system. The proposal in this study is to investigate the behavior of this material when subjected to the procedure for surface treatment and cleaning, and after application of a protocol cementation experienced in previous studies. 60 bars will be made of IPS e.max CAD. The groups will consist of 10 bars each, and will be submitted to the following surface treatments: A, no treatment; B, application of 10% hydrofluoric acid (HF) for 20s + wash (60s), dry (30s); C , HF (20s) + wash (60s), dry (30s) and cementation; D, HF (20s) + wash (60s) + neutralization with supersaturated solution of sodium bicarbonate (SB) for 40s + wash (5s) + dry (30s) and cementation; E, HF (20s) + wash (60s) + ultrasonic cleaning in deionized water (US) for 4 min + dry (30s) and cementation; and F, HF (20s) + wash (60s ) + neutralization with SB (40s) + cleaning in US (4 min) and cementation. The specimens will be tested using the flexural strength of three points and further evaluation of scanning electron microscopy of the fractured surfaces. (AU)