Morphological analysis of tissue reaction caused by a new endodontic paste in subcutaneous tissue of rats.

Aim: To assess the biocompatibility of an experimental endodontic paste based on the ethyl acetate fraction of Pothomorphe umbellata + calcium hydroxide, using propylene glycol as vehicle, in connective tissue of rats.

Materials And Methods: Fifteen rats had four polyethylene tubes implanted in their backs, with each one containing the experimental paste. The tube side was considered the control group.