Four-hundred seventy-seven teeth treated by periapical surgery by one surgeon were followed up until a stable radiographic situation was recorded. Radiographic findings were classified into one of four groups: 1, complete healing; 2, incomplete healing (scar tissue); 3, uncertain healing; or 4, unsatisfactory healing. Evaluation was performed independently by an endodontist and the oral surgeon and cases of disagreement were subjected to joint evaluation. Difficult cases and borderline cases were judged by an oral radiologist. Complete healing was observed for 78% and incomplete healings (scar tissue) for 9% of the teeth. The size of the latter group was strongly influenced by the number of cases with large preoperative lesions. When the material was grouped as "success" (complete healing, scar tissue healing) and "failure" (uncertain healing, unsatisfactory healing), a 13% failure frequency was recorded. Twenty-eight percent of the cases treated with retrograde fills failed compared with 4% in the orthograde group.