Periapical status of root-filled teeth exposed to the oral environment by loss of restoration or caries

Objective. Studies in vitro carried out on extracted teeth have demonstrated that bacterial elements may penetrate root fillings from the coronal to the apical end after a period of exposure to artificial saliva or bacterial culture. To address the clinical significance of this so-called issue of coronal leakage, a retrospective cohort analysis was conducted of 55 patients with root fillings that had been exposed to the oral environment because of caries or absent restorations. Study design. Cases were matched 1-to-1 with regard to initial pulpal and periapical diagnosis, period after completion of endodontic therapy, tooth type, age of the patient and the technical quality of the root filling. Only cases with a follow-up period of 3 years or more were included. Radiographs taken at the last follow-up examination were subjected to a masked evaluation. Results. A total of 14 osteolytic lesions were recorded, in 43 of the 55 matched pairs (78%), there were identical periapical conditions. In 9 pairs, a periapical lesion was present in the "open" tooth category, whereas in 3 pairs, a periapical lesion was seen exclusively in the "intact" tooth. Though the odds-ratio For a lesion to be present in the "open group" was 3.0, this was not a statistically significant result (P > .10). Conclusions. Data suggest that the problem of coronal leakage may not be of such a great clinical importance as implicated by numerous studies in vitro, provided instrumentation and root fillings are carefully performed.