The role of solvents on bonding to dentin

Author(s)

Fernanda Cristina Pimentel Garcia

• Document type: Doctoral Thesis
• Press: Bauru.
• Institution: Universidade de São Paulo (USP). Faculdade de Odontologia de Bauru (FOB/SDB)
• Defense date: 2005-04-07

Examining board members

Ricardo Marins de Carvalho; Maria Teresa Atta; Marcelo Giannini; Maria Aparecida de Andrade Moreira Machado; Manuel Toledano Pérez

• Advisor: Ricardo Marins de Carvalho
• Field of knowledge: Health Sciences - Dentistry
• Indexed in: Banco de Dados Bibliográficos da USP-DEDALUS
• Location: Universidade de São Paulo (USP). Faculdade de Odontologia de Bauru; FOB; G165e

Abstract

The present study aimed to test the effect of the molecular interactions between solvent and pure monomers with demineralized dentin matrix on its mechanical properties, evaporation rate and consequent change in the bond strength (BS). The mechanical properties were determined by measuring the apparent maximum modulus of elasticity (EMax) and stress relaxation (SR). The results indicated that the Emax is both time and solvent dependent; accordingly, the SR was both strain and solvent dependent. The weight loss (%) and evaporation rate of experimental mixtures (35%HEMA/65%solvents) were determined by the measuring of weight loss over time from different surfaces (demineralized dentin cubes x free surface). The overall evaporation rate and weight loss were higher for dentin cubes and dependent of solvents. The bond strength (BS) was determined by the microtensile test. The effects of surface shininess on bond strength of experimental primers to dentin were evaluated. Dentin surfaces were acidetched, primed with experimental mixtures in two (not shiny) or three (shiny) coats. For the all primers the presence of a shiny surface significantly improved resin-dentin bond strengths. The influence of storage time in resin dentin bond strength mediated by experimental HEMA/solvent primers was determined. Part of specimens were tested after 24 hour storage in deionized water (control) and remaining specimens were tested after 6 months and 1 year of storage in the same condition. Water storage resulted in reduced bond strength for most of the primers. This study develops a rationale that employs the solubility parameter theory to describe and analyze molecular interactions that occur during adhesive procedure to dentin, seeking to establish the cause-effect relationship. (AU)