Comparative Study of Wide-diameter OSSEOTITE Implants in Posterior Region

Objectives: The aim of this study was to compare the long-term implant and prosthetic outcome of OSSEOTITE wide-diameter dental implants (WDIs) versus standard-diameter implants (SDIs) placed in posterior jaws. Methods: Sixty-one out of 92 patients who received at least one OSSEOTITE WDIs and SDIs in the posterior region at Kaohsiung Medical University Hospital implant center between 1996 and 2007 were selected. During the examination, information regarding medical history, implant-specific, prosthetic, and surgical parameters were collected. Kaplan-Meier analyses with Log-rank test were applied to examine the difference in cumulative survival rates (CSR) between groups. The Kaplan-Meier estimate was applied to calculate implants success rates, and compared to the results of Log-rank tests for risk factors. The relative risks (RRs) of implants failure for clinical factors were determined using Cox-regressions. Risk factors associated with prosthetic complications were analyzed through Chi-square and Log-rank test. Results: Thirty-five men and 26 women with a mean age of 52.3 years (21 to 79 years) participated. The mean follow-up time for 113 WDIs and 145 SDIs was 57.2±33.6 months. Four WDIs and 3 SDIs failed during the period. The 10-year CSR for WDIs and SDIs were 95.6% and 97.9% respectively. No statistically significant difference was identified between these two implant groups. Implant diameter was not statistically correlated with implant survival when implant length was (p<.05). A total of 134 prostheses supported by 253 implants were fabricated. Only 1 set of prosthesis failed due to implant loss, resulting in a 98.81% prosthesis survival rate. Veneer fracture was the most frequent prosthetic complication, with fiber-reinforced composite (FRC) veneer and screw-retained design having a significant higher incidence. Conclusion: The present clinical study showed comparable survival rates between wide- and standard-diameter external hexed OSSEOTITE implants in posterior region. Implants less than 10mm length were found to have higher failure rates.