Intra-tubular reactions in restored human teeth: A SEM study

The aim of this study was to examine restored human teeth in order to evaluate tissue changes in primary dentin or in primary-secondary dentin continuum. 16 non-carious and restored human molars were used. All teeth were processed for scanning electron microscopic (SEM) analysis. Analysis was focalised at 3 parts of the dentin matrix; at the dentin-restoration interface, at the middle part of the remaining dentinal thickness and at the dentinpulp interface. The results showed that in most cases dentinal tubules were wide open, from the dentin-restoration interface to the dentin-pulp interface. No sign of dentinal sclerosis or tubular obturation was found. Consequently, dentinal tubules could provide a pathway for bacteria to penetrate the dentin pulp complex. Nevertheless, dentinal tubules under composite resin restorations seemed to have been sealed by the composite material, at the dentin-restoration interface. Parameters like the age of the patient, the reason of extraction or longevity of restoration did not, indirectly, affect by any way dentin continuum. In general, it can be concluded that unlike previously reported studies, dentinal sclerosis was absent in most of the teeth studied.