Pulp tissue response to carbonated hydroxyapatite as a pulp-capping material in a rat model

Objective: This study assessed the short-term pulp tissue response to carbonated hydroxyapatite (CHA) when used for direct pulp capping, in comparison with mineral trioxide aggregate (MTA).Methods: In this animal study, class V cavities were prepared on the labial surfaces of ۳۰ maxillary incisors from ۳۰ Sprague–Dawley rats. The animals were randomly assigned into three groups (n=۱۰) based on the pulp‑protective material applied: Group ۱: CHA, Group ۲: MTA, and Group ۳: No capping material (negative control). Following material placement, the cavities were restored with reinforced zinc oxide-eugenol cement. The animals were euthanized at ۷ and ۱۴ days postoperatively (n=۵), and histological evaluation was conducted to assess the degree of pulpal inflammation and the integrity of the odontoblastic layer.Results: At both ۷ and ۱۴ days postoperatively, the control group showed histological features consistent with chronic inflammation, whereas the CHA and MTA groups exhibited preserved pulp tissue architecture and an intact odontoblastic layer. Significant differences in inflammatory scores and odontoblastic layer integrity were observed among the groups at both time points (P<۰.۰۵). The control group demonstrated significantly higher inflammation and a damaged odontoblastic layer compared with the CHA and MTA groups (P<۰.۰۵).Conclusions: CHA elicited pulpal responses comparable to those of MTA at both ۷ and ۱۴ days postoperatively. Both materials demonstrated similar levels of inflammation and comparable preservation of odontoblastic layer integrity. These findings suggest that CHA may be a suitable alternative to MTA for early pulp preservation in vital pulp therapy.

کلیدواژه ها:

Carbonate apatite ، Dental pulp capping ، Dental pulp exposure ، Hydroxyapatites ، mineral trioxide aggregate ، Odontoblasts