Retention of crowns YTZP on different substrates, surface treatments and resin cements

• Grant number: 12/13322-3
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• Start date until: October 01, 2012
• End date until: June 30, 2013
• Field of knowledge: Health Sciences - Dentistry - Dental Materials
• Principal Investigator: Marco Antonio Bottino
• Grantee: Marilia Pivetta Rippe
• Supervisor: Roberto Scotti
• Host Institution: Instituto de Ciência e Tecnologia (ICT). Universidade Estadual Paulista (UNESP). Campus de São José dos Campos. São José dos Campos , SP, Brazil
• Institution abroad: Università di Bologna, Italy
• Associated to the scholarship: 12/03436-1 - Retention of crowns YTZP on different substrates, surface treatments and resin cements, BP.DR

Abstract

Y-TZP crown retention in differents substrates, surface treatment and resin cement The aim of this study is to evaluate the effect of coronal substrate type (dentin and composite resin) in the retention of Y-TZP ceramics crowns as well as compare the retention of 5 types of cements and three ceramic surface treatments. Molars teeth prepared for full crown (N=216) will be embedded in acrylic resin perpendicular to its long axis. Half of specimens will present the prepare in dentin and the other half, the coronal dentin will be removed and rebuilt with a glass fiber-reinforced post and composite resin. The preparations will be molded with addition silicone in order to obtain dies for manufacturing the Y-TZP infrastructure, which will have a special configuration for the tensile test. The cements used will be: conventional dual, self-adhesive resin cement chemically activated, self-adhesive dual (control), resin modified glass-ionomer dual (control) and zinc phosphate (control). In these groups the remaining (dentin or resin) will be conditioned with the corresponding adhesive system. The inner surface of the infrastructure will be submitted to three different surface treatments: isopropyl alcohol, silicatization/silanization and glass application followed by etching with hydrofluoric acid 9% (1 min). After 24 hours, all groups will be submitted to thermocycling (6,000 cycles) and positioned in a special device for tensile test in a universal testing machine to test retention of the infrastructure. The failure modes of all sets will be examined in a stereomicroscope and SEM to evaluate possible causes of failure. (AU)