Dentin bridge formation following direct pulp capping in dog's

The effectiveness of two different calcium hydroxide pastes; "Calvital and "Dycal", for the direct pulp capping in dog's permanent teeth with incompletely formed roots were evaluated in this study. Forty-eight vital permanent premolar teeth with incompletely formed apices were obtained from 6 dog's (6 months of age). Exposure sites on contralateral pairs of teeth were capped with either "Calvital" or "Dycal". Then intravenous injections of tetracycline were administered to the dogs at various intervals. Animals were sacrificed at 56 days. The teeth were fixed, undecalcified ground sectioned, observed by microradiography, and evaluated by ultraviolet light. In cases treated with "Calvital", a fluorescent line resulting from tetracycline administration 7 days after experimental procedures was seen in the newly formed dentin bridge. In cases treated with "Dycal", a fluorescent line resulting from tetracycline administration 14 days after experimental procedures was seen in the newly formed dentin bridge. Continued physiological root formation was observed well in all teeth. This experiment may explain why some "Dycal" failures occur in the earlier postoperative periods; serves as a stimulus potential for a hardening reaction.