Bioactivity and biocompatibility of bioceramic-based pulp capping materials in laboratory and animal models

Recently, premix bioceramic-based pulp capping (BPC) materials have been introduced with desirable properties. However, data regarding the bioactivity and biocompatibility of these materials remain limited. This present study aimed to evaluate the bioactivity and biocompatibility of BPC materials. This study consisted of five experimental groups: Bio C Repair (BCR); BG Multi (BGM); Well pulp ST (WPS); ProRoot MTA (PMTA); and a no capping (NC) group. Measurement of pH, calcium ion (Ca²⁺) release, and a bioactivity test were performed. An in vivo experiment was conducted on maxillary first molars of Wistar rats with exposed pulp, and pulpal responses were assessed at 1, 3, 7, and 28 days. Immunohistochemical expressions of Nestin, Osteopontin, and DMP-1 were performed. All materials exhibited alkaline pH. BCR exhibited the highest Ca²⁺ release (p < 0.05). PMTA, BCR, and WPS produced well-formed calcium phosphate depositions. On day 1, BCR, BGM and NC groups showed no to mild inflammatory responses (p < 0.05). On day 3, mild to moderate inflammatory responses was observed in all groups except for the NC group. On day 7, BCR and WPS groups exhibited no to mild inflammatory responses, along with the mineralized tissue layer formation (MTF). On day 28, no inflammatory responses were observed in the BCR, BGM, and WPS groups. Complete and homogenous MTF was identified in all experimental groups except the NC groups. Variable expression of Nestin, Osteopontin, and DMP-1 was noted at different time points. This present study demonstrated that premix BPC materials exhibited favorable bioactivity and biocompatibility and may serve as potential substitutes for PMTA.