Histologic evaluation of pulpal response to MTA and capsaicin in cats

Introduction: In direct pup capping, the exposed pulp is directly capped with a capping material to provoke a dentinal bridge formation to seal the exposed area.The aim of this study was to evaluate the pulpal response to MTA and capsaicin in cats. Methods: The sample for this experimental study consisted of 24 canines of cats, weighed approximately 3-4kg. After sedation, the teeth were cut and exposed at 3mm above cementoenamel junction, then divided into two groups: 1) direct pulp capping with MTA 2) direct pulp capping with Capsaicin. The cavities were filled with glass ionomer cement (Fuji IX). The cats were sacrificed in the first, second, and fourth weeks 4 canine teeth were extracted for the purpose of histologic analysis. 6Serial sections were cut parallel to the longitudinal axis of the canines. The sections were stained with hematoxylin & eosin, and were observed and analyzed using a light microscope. Results: In both groups treated with MTA and capsaicin, the inflammation decreased during weeks1, 2, and 4. Less inflammation was seen in MTA group but there was no statistical difference between the two groups (p=0.22). In the group treated with capsaicin, necrosis was observed in every 12 samples, but in the other group treated with MTA, only 1 pulp necrosis was seen in the first week (p=0.000). There was no significant difference in dentinal barrier formation, inflammatory response, and soft tissue changes between the two groups. Conclusions: The results of this study showed that capsaicin can decrease the severity of inflammation, but it is ineffective in dentinal barrier formation.