Dimensional change of demineralized dentin matrix produced by monomer/alcohol primer saturation and solvent evaporation

Abstract

The purpose of this work was to evaluate the use o_f ethanol ~nd methanol as ·, ' solvents for resin monomers and more specifically to evaluate their 'e'ffects on the expansion and modulus of elasticity of infiltrated demineralized dentin matrices, and the _ subsequent matrix shrinkage following solvent evap·oration. Twenty-eight dentin specimens approximately 200 J..tm thick were demineralized with thirty-seven percent phosphoric acid for four hours. The linear variable differential transformer portion of four thermomechanical analyzers were used to measure changes iti demineralized disc thickness upon solvent application, model-primer saturation, and solvent evaporation. Dentin matrix modulus of elasti~ity was measured while saturated with watervs. model primers. One-way analysis of variance and Students-Newman-Kuels post-hoc tests demonstrated a significant (p < 0.05) correlation between the solvent's Hoy's solubility parameter for hydrogen bonding, 8h, and its ability to expand the matrix. Solvents with higher 8h were able to expanded the matrix at a higher rate and extent. Regression analysis and analysis of covariance showed a significant (p < 0.05) correlation between the model primer concentration and matrix collapse upon solvent evaporation. Model primers with higher monomer concentrations demonstrated less matrix collapse upon solvent evaporation than more dilute primers.