Retrospective study on bone-level and soft-tissue-level cylindrical implants.

The purpose of this prospective clinical study was to evaluate the survival rate (SVR - i.e. fixtures still in place at the end of the observation period) and success rate (SCR - i.e. bone resorption around implant neck) of two cylindrical implant systems. Both systems were equipped with a tapered connection, one requiring a bone-level (BL) placement, while the other a soft-tissue-level (STL) placement. In the period between January 1996 and October 2011, a total of 150 implants (76 in females and 74 in males, mean age 60±11 years) were inserted. The mean post-surgical follow-up was 84±47 months. Several parameters were evaluated as potential outcome conditioners: age, gender, diabetes, smoking, periodontitis, type of edentulism, replaced tooth, jaw location (i.e. maxilla or mandible), bone graft, immediate loading, post-extractive, type of prosthesis, implant diameter and length. An SPSS program was used for statistical analysis. Only two fixtures were lost, therefore SVR was 98.7%. SCR, expressed through the mean marginal bone loss, was 92%. The mean peri-implant bone loss was 0.121.47 mm for BL implants and 0.041.3 mm for STL implants. None of the studied variables had a statistical significant impact on SVR or SCR. Cylindrical implants are reliable for oral rehabilitation.