Acrylic denture resins characterization: physical-mechanical properties and bonding to artificial teeth and reline material

• Grant number: 11/09562-6
• Support Opportunities: Regular Research Grants
• Start date: September 01, 2011
• End date: August 31, 2013
• Field of knowledge: Health Sciences - Dentistry - Dental Materials
• Principal Investigator: Carlos Eduardo Vergani
• Grantee: Carlos Eduardo Vergani
• Host Institution: Faculdade de Odontologia (FOAr). Universidade Estadual Paulista (UNESP). Campus de Araraquara. Araraquara , SP, Brazil
• Associated researchers: José Maurício dos Santos Nunes Reis

Abstract

Acrylic resins based on polymethyl methacrylate (PMMA) have been widely used for manufacture denture bases; even presenting some unsatisfactory physical-mechanical and biological properties. In order to overcome these drawbacks and simplify the laboratorial process of denture bases fabrication, a new polymeric system was developed. The new system for denture bases, based on urethane dimethacrylate (UDMA), is commercially known as Eclipse (DentsplyTrubyte, York, PA, EUA) and has been indicated as an alternative to PMMA. Eclipse has better biocompatibility, it is free of un-reacted methyl, ethyl, propyl or butyl methacrylate, and has ease of fabrication and manipulation by visible-light activation. Although Eclipse is being recent in dentistry, few studies were performed to evaluate its physical-chemical and mechanical behavior, simulating its use in the oral cavity conditions. Moreover, there is little information about the interaction of this material with autopolymerize resins, used for immediately relining technique. So, the purpose of this study will be evaluate and characterize the viscoelastic properties (E', tan´ e Tg), linear dimensional change, water sorption, water solubility, toothbrush wear resistance and degree of conversion of two denture base resins, one visible-light activated based on UDMA (Eclipse) and the other based on PMMA (Nature Cryl). These properties will be compared with those of the hard chairside reline resin (Tokuyama Rebase Fast II). Furthermore, the flexural strength of intact (not relined) and relined specimens (mediate and immediate relining) will be assessed by static and dynamic mechanical analyses as well as the shear bond strength of these resins to denture rebase materials and artificial teeth. (AU)