Reaction of rat molar pulp tissue to Formocresol, formaldehyde, and cresol

Abstract The maxillary molars of rats were exposed and treated for five minutes with either Formocresol, formaldehyde, cresol, or glycerol—a control solution-and then covered with zinc oxide-eugenol and amalgam. After the treatment, the animals were killed at weekly intervals for four weeks. Analysis of histolgic sections showed that formaldehyde did not inhibit or enhance pulpal recovery when compared with the control solution. Cresol greatly hindered healing, as indicated by the lack of dentin bridge formation within the time span of this experiment. Formocresol treatment slowed, but did not prevent, the resolution of the defensive reaction.