The purpose of this study was to investigate the long-term stability of apical retrograde root fillings using a dentin-bonded resin composite. Radiographs were used to establish the degree of healing around the apically filled roots. Patients examined were those who had previously showed complete healing 1 yr after surgery.Thirty-three of the first 34 consecutively placed resin composite apical fillings performed since the introduction of this method in 1984 were examined. Six of these fillings were examined 8 yr after surgery, and 27 of these fillings were examined 9 yr after surgery. Only one patient showed recurrence of periapical inflammation 8 yr after operation, probably caused by a root fracture. It was concluded that the bond established between dentin and the resin composite was stable during the observation period, and that the filling material had not been harmful to the surrounding tissues.If complete bone healing has been observed, it could be expected to remain stable, unless new factors, such as root fracture, occurred.