A critical clinical and television radiographic evaluation of indirect pulp capping

Abstract

The purpose of this study was to quantitatively measure the rate and amount of calcification and secondary dentin deposition below deep carious lesions of otherwise radiographically and clinically sound teeth treated by calcium hydroxide - methyl cellulose indirect pulp capping. Standardized, reproducible serial radiographs of 50 treated young posterior teeth were exposed preoperatively at one, three, six, nine and, in some cases, 12 months. At the final appointment, the silver amalgam restorations were removed and all residual caries was excavated. A barium sulphate radiographic indicator paste identified the pulpal floor level at the first and last appointments. Ninety per cent of the teeth studied remained asymptomatic and were not pulpally exposed. Television density and linear measurement instrumentation was utilized to register calcification changes, pulpal floor thicknesses, and secondary dentin deposition. Following treatment, increased secondary dentin deposition and Calcification activity, or sclerosis, was initiated. Higher levels of calcification activity were related to increased thickness of pulpal floors, but this dimension had little influence on the total amount of reparative dentin formed. The rate of reparative dentin formation was highest during the first month and steadily diminished with time. Calcification activity experienced a cyclical change, or "exchange," with an initial activity peak. This was followed by an apparent, but temporary mobilization of mineral content •out of the affected dentin. With time, a steady rise in calcification level was observed. Measurement of longitudinal records showed that apparent pulp exposures can be avoided by allowing significant amounts of protective secondary dentin to form, before complete caries excavation.