Eighty-nine periapical radiolucencies treated by nonsurgical endodontic therapy were evaluated to better understand the healing rates of these lesions. After at least 3 months after treatment, radiographs revealed that 46.1% of the lesions had resolved, 48.3% had undergone partial resolution, 2.2% were unchanged, and 3.4% were larger. The average radiographic rate of repair was 3.2 mm2/mo. Less than 6 months after treatment, 17.6% of lesions demonstrated complete radiographic resolution, whereas 70.6% showed radiographic resolution at 12 months or longer.