Dentin permeability: Effects of cavity varnishes and bases

Abstract

C avity lining materials are used to protect the pulp from possible injurious effects after restorative procedures. They are intended to provide a barrier against substances liberated from restorative materials, acidic components of cements, or the dehydrating effects of some restorative materials.‘-3 Lining materials should also prevent penetration of cavity margins and dentinal tubules by bacteria and their products, which are currently thought to cause most of the pulpal inflammation seen under restorative materials.4-6 Many techniques and procedures have been used to evaluate the permeability of cavity lining materials. Histologic examination of the pulps of teeth treated with various materials has been used for many years.‘, * Dies, silver nitrate, and autoradiographic studies have been widely used.2~9-‘9 Unfortunately, most of the previous work has been qualitative or semiquantitative at best. Several reports described quantitative techniques that can accurately determine the efficacy of lining materials to reduce marginal leakage and/or dentin permeability.20-23 As part of a systematic study of the permeability characteristics of dentin, two quantitative techniques have been developed to accurately measure dentin permeability. This report describes the use of these techniques in evaluating the ability of several cavity varnishes and bases to reduce dentin permeability.