HISTOLOGICAL-EVALUATION OF THERAPY USING A CALCIUM HYDROXIDE DRESSINGFOR TEETH WITH INCOMPLETELY FORMED APICES AND PERIAPICAL LESIONS

Periapical tissue response was evaluated histologically in teeth of 6- month-old dogs with incomplete root formation and periapical lesions i n order to compare the effects of two calcium hydroxide-containing pas tes prepared with different vehicles on induced root apex formation an d repair of the periapical region. A group of teeth with no root canal dressing was used as control. After induction of the periapical lesio n, the root canals were instrumented and filled with one of the two pa stes (Calen and Calasept), which were renewed monthly for 90 days. At the end of the follow-up period (3 months), the animals were killed. B lock sections from the actual areas were dissected free and prepared f or histopathological analysis. Both calcium hydroxide pastes helped in duce apical sealing and repair of the region, but the Calen paste yiel ded better results than Calasept. The induced mineralized tissue was p redominantly of the cementoid type after the use of both pastes, but t he inflammatory infiltrate was significantly less intense with the use of the Calen paste. In the control group, the absence of a root canal dressing impaired the process of periapical repair and yielded no api cal root closure in any of the cases analyzed.