This study aimed to evaluate the pulpal responses of monkey's pulp after direct pulp capping (DPC) with the novel mineral trioxide aggregate containing phosphorylated pullulan-based material (MTAPPL). Seventy-two teeth were randomly divided into four groups: MTAPPL; Nex-Cem MTA (NX); TheraCal LC (TH); and Dycal (DY). Histopathological changes in the pulps were observed at days 3, 7 and 70. On day 3, mild inflammatory responses were observed in the MTAPPL, no to moderate inflammatory responses in the TH, whereas moderate inflammatory responses in the NX and DY. No mineralized tissue formation (MTF) was observed in all groups. On day 7, no or mild inflammatory responses were observed in all groups. Initial MTF was observed except for DY. No inflammation with complete MTF including presence of odontoblast-like cells was observed in the MTAPPL, NX and TH groups at day 70. These findings indicate that MTAPPL could be an efficient DPC material.
Keywords: Calcium hydroxide; Direct pulp capping; Mineral trioxide aggregate; Phosphorylated pullulan.