RESUMO
The aim of this study was to observe the histopathological pulp response following direct pulp capping of mechanically exposed teeth in rats with a composite of beta-tricalcium phosphate-hydroxyapatite bioceramic (BC) and poly (glycolic)-poly (lactic acid) (PLGA) material or a calcium hydroxide [Ca(OH)2] material, compared to BC alone and a negative control of water. Pulp of the maxillary molars was exposed, followed by capping with the experimental material. The pulpal tissue response was assessed post-operatively at 1, 7, 14 and 30 d, followed by histological analysis. The Ca(OH)2 group exhibited severe acute inflammatory cell infiltration at day 14. However after 30 d, a new hard tissue with macro porous obliteration of the pulp chamber and a characteristic necrotic area had appeared. BC and Ca(OH)2 capping were associated with moderate inflammation and dentinal bridge similar. Meanwhile, in the BC/PLGA composite group, there was moderate inflammatory infiltrate and formation of a dense and complete dentinal bridge. In conclusion, the BC/PLGA composite material showed a large zone of tertiary dentin, and effectively reorganized the dentin-pulp complex.