Marginal fit and flexural strength of a lithium disilicate ceramic precessed BU CAD/CAM or conventional injection

• Grant number: 12/17245-3
• Support Opportunities: Regular Research Grants
• Duration: December 01, 2012 - November 30, 2013
• Field of knowledge: Health Sciences - Dentistry - Dental Materials
• Principal Investigator: Graziela Avila Galhano Logar
• Grantee: Graziela Avila Galhano Logar
• Host Institution: Faculdade de Odontologia Dr Mario Leite Braga. Universidade do Oeste Paulista (UNOESTE). Campus de Presidente Prudente. Presidente Prudente , SP, Brazil

Abstract

The processing technique of dental ceramics is directly related to the final characteristics of these materials. Thus, this study aims to evaluate the flexural strength and marginal adaptation of a ceramic-based lithium disilicate processed by technical CAD / CAM and conventional technique. To evaluate the marginal fit 10 models will be made from a metal die, which will be held on scanning to obtain the virtual model for the processing of ceramic lithium disilicate for technical CAD / CAM and later the same models will be used to the technique of conventional injection. Are then obtained the plaster models, which will be held scanning, design and software infrastructure in order to obtain the ceramic milling CAM / CAM (10 samples), and the production of copings to conventional injection, using the lost wax technique ( 10 samples). The analysis of marginal discrepancy will be in 12 point margin of metallic die, and the values will be submitted to the arithmetic mean getting a single average value for each crown. For evaluation of the flexural discs 10 are fabricated from a wax matrix of stainless steel, which is held on the preparation of specimens by the lost wax technique. On these same disks are made of wax the specimens with the CAD / CAM system, where the scanner will be held from the milling of the ten blocks. For evaluation of flexural strength will be performed biaxial bending test on three balls, in which the results are calculated using equation determined by standard ASTM F-394-78 for determining the value of the biaxial flexural strain for this type of assay. To analyze these results leave the hypothesis of equality. A statistically significant difference, will be tested by means of analysis of variance model. The level of significance is the conventional value of 5%. The hypothesis is that the ceramic CAD / CAM has a lower marginal discrepancy and higher flexural strength. (AU)