Pulpal tissue reaction to formocresol vs. ferric sulfate in pulpotomized rat teeth.

The purpose of this study was to assess histologically the pulpal healing process after pulpotomies in rat teeth were done using two different agents: 20% dilution of formocresol (FMC) and ferric sulfate (FS). Two criteria were used: degree of inflammation and extent of pulpal involvement. Zinc oxide-eugenol paste (ZOE) or polycarboxylate cement (PCX) were placed to seal the cavity preparations. The maxillary first molars of 120 Sprague-Dawley rats were treated in this study and were divided into four groups: 1) FMC + ZOE, 2) FS + PCX, 3) FMC + PCX, and 4) FS + ZOE. After treatment the animals were sacrificed at weekly intervals for four weeks and pulpal response was evaluated according to the degree of inflammation. Other criteria were also evaluated: dentinal bridge formation, reparative dentin and odontoblastic layer. A Friedman test was performed to compare the results and find out if any differences could be found. FMC + ZOE group showed the least pulpal inflammation response, and the use of FS as an alternative agent for pulpotomies did not improve pulpal response.