Clinical outcome of Screw Vent implants - A 7-year prospective follow-up study

The clinical results of 85 Screw Vent implants are described with respect t o 7-year success, including radiographically detectable bone loss, survival and prosthetic quality. The 1-year results of the same material have been reported previously (De Bruyn et al. 1992). Implants were considered as suc cessful when they were meeting with the success criteria proposed by the Eu ropean Academy for Periodontology. From the 85 implants originally installe d, 16 failed during the 7-year interval (18.8%), 6 were unaccounted for (7% ), 21 (24.7%) did not meet the success criteria yet survived and 42 implant s (49.4%) were successful. The success rate was 65.2% for the mandibular an d 43.5% for the maxillary implants. Implant failures were irrespective of i mplant length, smoking habits, prosthetic quality or oral hygiene level. Fr om 24 patients with a corresponding number of 60 implants, radiographs were available for bone loss analysis. The mean bone loss after 7 years was 2.9 2 mm (range -0.5 to 6.3); 18 out of 60 examined implants (30%) showed unacc eptable radiological bone loss beyond the critical value of 2.7 mm. Implant material analysis and histomorphometric analysis of a retrieved implant ar e discussed. In the present clinical study, the Screw Vent implant system d oes not meet the success criteria proposed by the European Academy for Peri odontology. The ongoing bone loss increases the risk for future implant fai lures and peri-implant disease.