Histopathologic Responses of Dog’s Dental Pulp to Mineral Trioxide Aggregate, Bio Active Glass, Formocresol, Hydroxyapatite

Introduction: Bio Active Glass (BAG) is often used as a filler material for regeneration of dental bone defects. Mineral trioxide aggregate (MTA) is used as retrofilling agent, repair of root resorption and pulpotomy agent in primary dentition. Formocresol (FC) is old and standard fixation agent in pulpotomy procedures. Hydroxyapatite (HA) is a biologic constitute. It is used in ridge augmentation, bony defect repair and pulpotomy agent in teeth. The purpose of this study was evaluation of histopathologicresponses of dog’s dental pulp to MTA, BAG, FC and HA after three months follow up.Materials and Methods: For this experimental prospective study forty-eight teeth were randomly selected in four dogs. Animals were anesthetized and pulpotomized. Three months later, animals were anesthetized and sacrificed. Then, teeth were extracted and histologic sections were prepared. Histologic sections were observed by an oral pathologist. The sections were observed from the viewof inflammation, hyperemia, necrosis, vitality, calcification and dentinal bridge. Relative frequency of histopathologic outcomes of dental pulp was analyzed and reported. Mean differences of fourgroups were analyzed by Kruskal-Wallis and Mann-Whitney tests.Results: Relative frequency of inflammation of FC, MTA, HA and BAG groups were 29.2, 25.9, 42.4 and 29.2 percent, respectively. Relative frequency of hyperemia of FC, MTA, HA and BAGgroups were 75.1, 63.6, 59.2, 81.6 and 62.5 percent, respectively. Relative frequency of necrosis of FC, MTA, HA and BAG groups were 29.2, 11.1, 12.1, 0 percent, respectively. Relative frequency ofcalcification of FC, MTA, HA and BAG groups were 75, 51.9, 69.7 and 54.8 percent, respectively. Relative frequency of dentinal bridge of FC, MTA, HA and BAG groups were 29.2, 70.4, 30.3 and 29.2 percent, respectively.Conclusion: Histopathologic reactions of dental pulp to four materials (MTA, HA, BAG, FC) were different. Histopathologic outcomes of MTA was more proper than those of BAG, HA and FC. Considering these findings, use of mineral trioxide aggregate and bioactive glass in pulpotomy is more favorable than using Formocresol and Hydroxyapatite.