Peri-implant bone density around implants of different lengths: A 3-year follow-up of a randomized clinical trial

OBJECTIVES Short dental implants are frequently placed, however, little is known about the effect of the loading force regarding an enhanced crown-to-implant ratio. The aim of this study was therefore to assess bone density changes after a 3-year period, on radiographs acquired from a randomized, controlled two-centre clinical study comparing implants of 6 and 10 mm of length. MATERIALS AND METHODS Three predefined areas were chosen on standardized X-rays in order to assess grey-scale values of the peri-implant bone: One at the tip of the apex and two at half-length on the mesial and distal sides of the implant. Radiographs at all follow-up appointments had previously been calibrated using control fields in areas of constant density. RESULTS Around short implants, peri-implant bone displayed significantly higher differences in grey-scale values (p = .031) after 3 years, indicating a higher degree of mineralization. This phenomenon was not observed around long implants. CONCLUSIONS A higher degree of mineralization around short implants was recorded. Whether this finding goes along with hampered bone adaptability, and accordingly, higher failure rates of short implants must be studied further in long-term clinical trials