Effect of Cortical Bone on Dental Implant Stability Quotient Values

Abstract

Wireless resonance vibration frequency analysis (RFA) is one of the new methods for measuring implant stability. The implant stability quotient (ISQ) values obtained using Osstell mentor make it possible to evaluate the implant stability non-invasively and objectively. However, few attempts have been made to examine the ISQ values using Osstell mentor and its relation with the implant stability of cortical bone (its thickness, width and density). In this study, we investigated factors affecting the ISQ value obtained by wireless RFA using mandibular cortical bone models of a pig.
After preparing pigʼs mandibular bone having different bone densities by the decalcifying method, pigʼs bone models excluding cavernous bone were made. We installed an implant fixture (Replace Select Tapered) in the pigʼs bone models under various conditions of thickness, width and density and examined the ISQ values by wireless RFA. We also investigated the correlation between ISQ value and length (10 mm, 13 mm and 16 mm) or width (3.5 mm, 4.3 mm and 5.0 mm) of the implant fixture installed in the model.
The results are summarized as follows:
1. ISQ value was significantly lower in the bone models with low density of cortical bone than those with high density.
2. ISQ value was higher in the bone models with high thickness of cortical bone than those with low thickness. However, a significant association was not found.
3. There were no differences between ISQ value and width of cortical bone.
4. There were no differences between ISQ value and length of implant fixture.
5. ISQ value of the fixture with narrow width (3.5 mm) was significantly lower than those with wide width (4.3 mm and 5.0 mm) in the bone model with low density of cortical bone.
These results indicated that ISQ values obtained by wireless RFA were affected by the bone density and thickness of cortical bone. Wireless RFA is a useful method for measuring implant stability.