Remaining Dentin Thickness and Pulp Response After Six Weeks

Objectives:The purpose of this study was to evaluate the effect of remaining dentin thickness of prepared cavities on the dental pulp health of human teeth.Methods:Twenty-four human premolars scheduled for extraction for orthodontic reasons were used in the study.The teeth were divided into two groups.In the groups, Standard class V buccal preparations were made in two depth (1mm and 2 mm).The cavities were restored with a bonding agent ( Scotchbond Multi Purpose-3M) and a composite material ( P-50,3M) according to the manufacturer's instructions.The teeth were extracted after six weeks. The specimens were then decalcified,sectioned,processed and stained with hemotoxylin and eosin for light microscopy.The remaining dentin thickness of cavities were measured and the specimens were classified into two groups (< 500 and > 500 microns). The samples were graded for odontoblast layer disruption,inflammation and vasculature changes.Statistical analysis were performed using Kruskall-Wallis one-way ANOVA and Mann-Whitney U Test. Results:The findings on the histological sections showed that remaining dentin thickness significantly affected the health of pulp.There was statistically significant difference between two cavity groups.None of the teeth presented severe inflammatory pulpal reactions histologically.But the more marked reactions were seen in sections found beneath the very deep restorations.In two deep cavities reparative dentin formation was observed. Conclusion: Cavity preparation depth is the main factor influencing pulpal reaction under restorative materials