This study investigated the frequency of periapical lesions following pulpal necrosis in vital teeth used as abutments in periodontal-prosthetic therapy. The study was conducted on a continuative series of 1000 teeth treated at least 2 years before the start of the investigation. 500 teeth were treated by specialist and 500 by general practitioners. The dental records of this sample were stored into a computer, analyzed and compared, and the chi-square index was calculated. Periapical lesions were found in 22.6% of the teeth. Maxillary incisors had the highest number of lesions (36.8%). The percentage of lesions increased as periodontal involvement became more severe (37.2%) with severe involvement as opposed to 18.5% with moderate involvement). The frequency of lesions was lower in the group of teeth treated by specialists than in the group treated by general practitioners (13.8% as opposed to 31.4%).