The inflammatory response of the pulp after direct capping with platelet-rich plasma and enamel matrix derivative: A controlled animal study

Aims: To evaluate the inflammatory response of the exposed pulp of incisor teeth in rats after direct pulp capping, using platelet rich plasma (PRP), enamel matrix derivate (EMD), mineral trioxide aggregate (MTA) and calcium hydroxide (Ca(OH)2). Methods: The study was conducted on 36 Wistar albino rats with a total of 144 incisor teeth. The pulps of 96 teeth of the rats were perforated and capped with different agents. Serving as the positive control group, the pulps of 24 teeth were only perforated and capped without capping agents, whereas the pulps of 24 teeth were used as the negative control group without being perforated (without any process). The research was ended with the extracting of the teeth on the 7th day 28th day. The teeth were taken to the routine and histological follows; cross sections were prepared and painted with hematoxylen & eosin. All of the sections were evaluated in terms of inflammatory reaction by histologic analysis taken by light microscope. Statistical analysis was used. The normal distribution of all data was tested with the Mann Whitney U and the differences between the groups were analyze dusing Kruskal Wallis test at 0.05 level. Results: There are no statistically significant differences in terms of inflammation type and necrosis among the treatment groups on 7 days’ post capping. However, improved inflammatory cell accumulation, hyperemia and lowest necrosis were observed from the samples treated with PRP (p < 0.05). Conversely, the EMD group indicated that the criteria of inflammation scores and hyperemia were higher in the 28th day (p < 0.05). Conclusions: Most of cells accumulating in the PRP group and most necrosis were seen in the EMD group. These new PRP materials might serve as pulp capping biomaterials to induce initial healing response in the future.