RESUMO
This study investigated the effect of doxycycline irrigation on wound healing and the apical seal of three filling materials. Part 1: 220 extracted teeth received root canal therapy followed by root resection (2 mm) and ultrasonic root end preparations (3 mm). Groups of 20 were irrigated with saline, citric acid, or doxycycline and filled with amalgam, Super EBA, or MTA. Leakage was measured (mm) after decalcification and clearing. Part 2: two defects were made on each side of the mandible of 10 New Zealand rabbits. On each side, one defect was irrigated with saline and one with either citric acid or doxycycline. The animals were killed in groups of five at 9 and 18 days. Sections of each defect were stained with hematoxylin and eosin for evaluation of healing and bone fill. Super EBA and MTA leaked significantly less than amalgam, regardless of irrigant. Leakage after irrigation with doxycycline compared to citric acid or saline was not significantly different for Super EBA or MTA but was lower for amalgam. There was no significant difference in healing or bone fill among irrigants at 9 or 18 days.