An experimental evaluation of endodontic procedures and filling materials

Radionuclide imaging was evaluated as a diagnostic tool in predicting the outcomes of endodontic procedures. Endodontic techniques intended to produce successful or unsuccessful results were performed on the molars of six dogs, and the effects on apical tissues were followed radiographically and by imaging over a 14-week period. Abnormally high uptake of radionuclides was observed during the first month following treatment in all teeth, regardless of the technique used. Persistent high uptake beyond that time was found to be associated with a failing course of therapy. Various root canal filling materials were also tested for their effects on bone formation in a rabbit model of healing bone. Experimental bone formation was inhibited by two commercial canal cements but not by either gutta-percha or silver points. It was tentatively concluded that the inhibitory effect of cements may serve to suppress heightened bone turnover associated with apical breakdown.