OBJECTIVETo evaluate the outcome and the potential prognostic factors of apical microsurgery.

METHODSThe teeth with persistent periapical diseases were treated by microsurgery using micro instruments, ultrasonic retrotips and mineral trioxide aggregate (MTA) under dental operate microscope. The procedure includes incision and flap retraction, osteotomy, apicoectomy, retro- preparation and retro- filling of root canal. Patients were recalled at 1, 3, 6, and 12- month intervals. The outcome was evaluated by clinical and radiographic examinations, and the potential prognostic factors were analyzed.

RESULTSOne hundred and eighty cases (240 teeth), including 132 upper anterior teeth, 22 lower anterior teeth, 31 upper premolars, 18 lower premolars, 19 upper molars and 18 lower molars, were treated by microsurgery between July 2010 and December 2012. A total of 152 cases (207 teeth) were recalled. The application of the apical microsurgery included failure of previous endodontic treatment, periapical lesion with post, periapical cyst, calcified canals, separated instruments, overfilling, open apex, root facture, failure of previous apical surgery, apical fenestration, and special root canal system. The success rate was 90.8% (188/207). Age, sex, tooth position, type of periapical radiolucency, fistula and clinical application type appeared to have a negative effect on the outcome. Endo-perio lesion was a significant factor. Eighteen cases (19 teeth) failed mainly because of periodontally involved lesion and vertical root fracture.

CONCLUSIONSApical microsurgery, which combines the magnification and illumination provided by the microscope with the proper use of micro instruments, can treat the teeth with persistent periapical diseases precisely and less traumatically with high success rate. Case selection and standardized operations play a key role for success.