A follow-up study of maxillary implants supporting an overdenture: clinical and radiographic results.

PURPOSE Studies of maxillary overdentures supported by endosseous implants often show a high implant failure rate. The aim of the present investigation was to evaluate clinically and radiographically non-submerged implants supporting an overdenture in the maxilla. MATERIALS AND METHODS Forty-one patients were consecutively admitted for treatment. The standard procedure was to place 4 implants and to mount a U-shaped bar for overdenture connection. When the overdenture was delivered to the patients, peri-implant parameters were recorded and radiographs were taken. All patients were required to follow a maintenance care program. In the context of this study, all patients were clinically examined and the peri-implant parameters were compared. Crestal bone loss was analyzed using linear radiographic measurements. A life table analysis was applied to calculate the cumulative survival rate (CSR). RESULTS Three implants failed in the early healing phase, and 3 patients lost 6 implants during the loading period. The 5-year CSR of all implants was 94.2%. The peri-implant parameters gave evidence of healthy soft tissues and good oral hygiene. The increases in probing depths and attachment loss were significant (P < .05). The mean marginal crestal bone loss was about 0.7 mm and was statistically significant at mesial and distal sites (P < .001). DISCUSSION The correlation between clinical attachment loss and crestal bone loss was not significant. Pronounced marginal bone loss was found around some implants. CONCLUSION In planned maxillary overdenture treatment, it is possible to achieve a satisfactory survival rate of the implants.