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 demonstrate d that bacterial elements may penetrate root fillings from the coronal to t he apical end after a period of exposure to artificial saliva or bacterial culture. To address the clinical significance of this so-called issue of co ronal leakage, a retrospective cohort analysis was conducted of 55 patients with root fillings that had been exposed to the oral environment because o f caries or absent restorations. Study design. Cases were matched 1-to-1 with regard to initial pulpal and p eriapical diagnosis, period after completion of endodontic therapy, tooth t ype, 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. Radiograph s taken at the last follow-up examination were subjected to a masked evalua tion. Results. A total of 14 osteolytic lesions were recorded, in 43 of the 55 ma tched 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. Thou gh the odds-ratio For a lesion to be present in the "open group" was 3.0, t his 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 vitr o, provided instrumentation and root fillings are carefully performed.