RESUMO
PURPOSE: The purpose of this in vitro study was to determine whether placement of a resorbable collagen barrier at the apical one third of the root canal could prevent extrusion of pulpectomy filling material. METHODS: Twenty-five extracted primary mandibular second molars, with at least two thirds of root length remaining, were used. The apical third of each root was covered with utility wax, and teeth were embedded in acrylic. Carious tooth structure was removed, crowns were reduced to a flat surface, and canals were accessed and preflared. Working lengths were established by reducing file lengths 2 mm short of the anatomic apex. Cleaning and shaping was performed using hand and rotary files, and canals were irrigated with sodium hypochlorite and dried with paper points. CollaCote was randomly packed into 1 of 2 prepared canals, and obturation was performed with Vitapex. Postoperative radiographs were independently evaluated for the presence of overfilling, and data were statistically analyzed using chi-square analysis. RESULTS: Overfilling was observed in 16% (4/25) of the CollaCote treated canals and in 42% (10/24) of canals when no barriers were used (P = .047). CONCLUSION: The application of CollaCote at the apical one third of the canals did not completely prevent, but did significantly decrease, the risk for overfilling in primary molars.