Histological analysis of human pulp following direct pulp capping with different materials: An ex vivo study

The predictability of direct pulp capping (DPC) depends on the quality of the dentin bridge formation and the inflammatory response to the capping material. Various materials are available with variable success.

The aim of this study is to evaluate histologically the effectiveness of calcium hydroxide, mineral aggregate, and dentin bonding agent when used as DPC in mechanically exposed adult pulp tissue.

Pulpal exposures were made in 45 intact human premolars, scheduled for extraction for orthodontic purposes. Teeth were capped with hard setting calcium hydroxide (Dycal), mineral trioxide aggregate (ProRoot MTA), and dentin bonding agent (adper Single Bond). The final restoration was done with posterior composites using resin-modified glass-ionomer cement as a base. Pulps of teeth were evaluated histologically at the 15^th and 45^th day for inflammatory cell response and dentin bridge formation according to the criteria described by Cox et al. The statistical analysis of data was done using Chi-square test and P ≤ 0.05 was considered statsiticlly significant.

MTA as DPC agent showed milder inflammatory response compared to Dycal and Single Bond. The quality of bridge formation by MTA was similar to Dycal, which took the least time. Adper Single Bond Plus and Dycal showed a significantly higher degree of pulpal inflammation. Among all materials used, Adper Single Bond Plus took the longest time for both the resolution of pulpal inflammation and improvement of the quality of bridge formation.

Based on the result, it can be concluded that Dycal and MTA produce similar types of dentin bridge formation when used a DPC agent. Adper Single Bond has the potential to be used as DPC agents, but it takes a longer time for the resolution of inflammation and dentin bridge formation.