Histopathologic evaluation of the pulp after direct pulp capping with calcium hydroxide and mineral trioxide aggregate in primary teeth

Mineral trioxide aggregate (MTA) is a relatively new material. It is biocompatible and has sealing ability. The purpose of this study was to evaluate the histologic pulp responses of calcium hydroxide and MTA placed directly on exposed pulp tissues. Twenty teeth already scheduled for extraction for orthodontic reasons were selected for this experimental study. These teeth were divided into 2 groups and treated with direct pulp capping. Calcium hydroxide was used for 10 teeth and MTA for 10 teeth. After 60 days the teeth were extracted and prepared for histological evaluation. Finally the data were analyzed with Mann-Whitney test. All teeth treated with Calcium hydroxide showed inflammation. Internal resorption was seen in 6 teeth and abscess in 5 teeth and calcified bridge in 6 teeth and reparative in 2 teeth. Inflammation was seen in 2 mineral trioxide aggregate samples and calcified bridge and reparative dentin in 7 teeth. Internal resorption and abscess were not seen in mineral trioxide aggregate group. Mineral trioxide aggregate appeared to be superior to Calcium hydroxide as a pulp capping agent in primary teeth.