Stability values of titanium dioxide-blasted dental implants in edentulous maxillas: a 3-year pilot study

The purpose of this follow-up study was to measure the resonance frequency of Astra Tech TiO(2) blasted implants at second surgery, at one and 3 years of loading. Secondly, it was investigated whether resonance frequency at second surgery could discriminate between successful implants and those that will fail over a 3-year period. Fifty titanium dioxide-blasted implants in eight consecutive patients with edentulous maxillas seeking fixed rehabilitations, were included in the study at abutment connection after 6 months of healing. Resonance frequency, clinical and radiographic records were obtained at abutment connection and after one and 3 years of loading. The cumulative survival rate after 3 years was 100%. The mean resonance frequencies were 65 +/- 4.8 implant stability quotient (ISQ) at second surgery (range 50-78 ISQ), 66 +/- 3.4 ISQ after 1 year of loading (range 53-76 ISQ) and 64 +/- 3.8 ISQ after 3 years of loading (range 53-77 ISQ). No significant differences resulted between these three time points. The marginal bone level decrease of 0.6 mm between the second surgery and the 3-year follow-up was observed. One limitation of the study is that no late failures were encountered in this relatively small sample. Consequently, it was not possible to establish a cut-off ISQ for implants that, after abutment connection, would maintain their stability over a 3-year period. Nevertheless, it might be concluded that following the first year of loading the range of 53-76 ISQ describes the stability of osseointegrated Astra Tech TiO(2) blasted implants.