Investigations Leading to Improved Dental Restorative Materials

摘要

Permeability studies were performed on rubbery polymer liner films. Diffusion through the polymer film was definitely slower than the diffusion through the acetate film, even when the acetate film was double the thickness of the polymer film. In an attempt to study the loci of diffusion in model restorations, the uses of a fluorescent dye and an ultra-violet light, showed micro-leakage in many of the diffusion cells. In those exhibiting no leakage, a slow diffusion rate was observed, which was of equal velocity for all types of restorations. Thermocycling grossly affects the adhesion at the tooth/ epoxide interface in samples with uncoated preparations as well as those that were polymer lined. The presence of silane in the preparation with and without liner, protected the restorations from leakage after thermocycling. The load to failure of the restorations was once again enhanced by the addition of liner to the preparation. This enhancement was even more significant when Silane A-1100 was used with the polymer liner. The silane also markedly protected the adhesive bond from the effects of prolonged moisture exposure. The effects of thermocycling of tooth specimens were also evaluated in relation to cure time and effect of repetitive thermocycling in the various preparations. (Author)