Clinical Performance of Dental Implants Placed in Sites of Previous Early Implant Failure: A Retrospective Analysis

Objectives: To evaluate the intermediate long-term clinical performance and success rate of dental implants inserted into sites of previous early implant failure.
Methods: A retrospective evaluation was conducted on 6456 patients from January 2004 to December 2011. Of these, 83 were tested for presenting with early dental implant failure. The collected data included patient´s characteristics, implants characteristics (failed and replaced), and any additional surgery performed prior or at the same of implant placement to obtain proper hard tissues dimensions. Moreover, peri-implant clinical parameters, marginal bone loss, and the implant quality scale of the replacement implants were recorded after delivering of the final prosthesis and annually thereafter.
Results: Sixty-six patients (male: 38; female: 28; mean age: 42.3±18.2 years old) with early implant failure received a total of 67 replacement dental implants. Three patients with 3 implants dropped out of the study during the mean follow-up of 69.4±27.0 months. The implant length and diameter were varied for 7 sites. The number of sites that required additional surgeries increased from 18 (26.9%) to 24 (35.8%) for first and replacement implant insertion, respectively. One of the 67 replacement implants failed before prosthesis delivery, and 1 implant failure occurred 20 months after prosthesis delivery, which represented a cumulative survival rate of 94.6%. At last follow-up evaluation, the overall mean marginal bone loss was 1.7±1.3mm. Two out of 64 implants failed according to implant quality scale criteria, 3 implants showed satisfactory survival, and 1 implant showed compromised survival. No pain or tenderness was observed in the rest 58 implants evaluated, showing a success rate (optimum health) of 90.6%.
Conclusions: Within the limits of the present study, early implant failure was not an obstacle for implant replacement at the same site after an adequate soft and hard tissues healing period using implants with treated surfaces.