Survival and Success of Zimmer dental implants placed at a University Hospital: Five-year results

Objectives: To assess the outcome (clinical and radiographic success and survival) of dental implants placed at the Aga Khan University Hospital in last five years.
Methods: A retrospective charts review was done from June 2010-June 2015. A record of 212 implants was retrieved. In addition to patient age, gender and systemic status, variables such as length and diameter of implants, bone grafting, type of definitive prosthesis (crown or bridge or over denture), nature of retention (cement versus screw retained), loading strategy (immediate versus delayed loading) etc. were analyzed. Descriptive statistics and frequency distribution were computed. Chi square test was applied to compare the association between categorical variables. The unit of analysis was implant. Level of significance was kept at <0.05.
Results: Out of 212 implant fixtures placed, 6 implants failed to integrate at 100th day assessment. One more implant failed at six months of loading. Data analysis was done 170 implants whose complete follow-up data were available. The follow-up range was from 6 months to 60 months. Most of the patients who received dental implants were partially edentulous, the most common length was 11.5mm, and the most frequent diameter was 4.7 mm. The seven failed cases had following common variables: deficient bone volume in maxilla (or placement of bone graft), non-submerged protocol (or early loading with prosthesis) and presence of diabetes.
Conclusions: We achieved a success rate of 96.69%. Factors affecting outcome of implant success include atrophic maxilla, premature loading, and presence of medical co-morbids especially diabetes.