The Effect of Implant Length and Diameter on the Primary Stability in Different Bone Types

The focus of this paper is to evaluate the influence of mechanical characteristics of the implant on primary stability in different bone types, based on resonance frequency analysis (RFA). A number of 60 Nobel Biocare Replace Select TiUnit Tapered implants of two different lengths (10 mm and 13 mm) and three different widths as 3.4 mm (narrow platform (NP)), 4.3 mm (regular platform (RP)) and 5 mm (wide platform (WP)) were placed into two different groups of bone blocks. Bone blocks were different in bone quality, but similar to bone types D1 and D3. Immediately, after implant placement, implant stability quotient (ISQ) was measured using the Osstell mentor device. ISQ values for implant placements in D1 bone were significantly higher than those for implants placed in D3 bone. In D1 bone, the implant length did not make any significant difference in primary stability; however, in D3 bone, the primary stability of the implant increased when longer implants were utilized. NP implants presented significantly lower ISQ values compared to the two wider implants. In cases of low bone quality, the optimum increase in the implant length and diameter should be taken into account to achieve higher primary stability.