Resumo:
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.
