Evaluation of direct pulp capping in carious primary molars: a 12-month randomized controlled clinical trial

Introduction
Direct pulp capping (DPC) is a minimally invasive vital pulp therapy for exposed pulp intended to encourage pulp healing and maintain vitality of a primary tooth till exfoliation.

Objectives
The aim of the study was to evaluate clinical and radiographic DPC outcomes using mineral trioxide aggregate (MTA) or hard-setting calcium hydroxide (Dycal) in carious exposed primary molars, and to assess the effect of exposure location on these outcomes.

Material and methods
Fifty-two primary molars in 32 children, aged 4-7 years, presenting with a deep carious lesion and vital pulp requiring vital pulp therapy were included. Molars were randomly assigned into two equal groups according to capping agent, i.e., MTA and Dycal. According to the site of pulp exposure, each group was further sub-divided into two sub-groups, i.e., pulpal or axial. All children were followed up clinically and radiographically for 12 months.

Results
The MTA group with pulpal pulp exposure showed 100% overall success rate after 12 months of follow-up, while in the axial pulp exposure group, the overall success rate was 46.2%, with a statistically significant difference (p = 0.004). In the Dycal group, the overall success rate was 75% after 12 months of follow-up for both axial and pulpal exposure, with no statistically significant difference (p = 1). There were no significant differences between MTA and Dycal groups, both pulpally and axially (p > 0.05).

Conclusions
Both materials showed comparable results as DPC agents in carious exposed primary molars, especially when exposures were pulpally located. MTA showed a lower success rate when pulp exposure was located on the axial wall.