Bone Density and Histomorphometry Assessment of Dental Implant Using Computerized Tomography

Son, Jang Ho; Choi, Byung Hwan; Park, Soo Won; Cho, Yeong Cheol; Sung, Iel Yong; Lee, Ji Ho; Byun, Ki Jung

Abstract

Bone density in the recipient implant site seems to be an important factor for long term success of endosseous implants. Preoperative evaluation of bone density is very helpful to assist the clinician with the treatment planning of implant therapy. Accurate information on bone density will help the surgeon identify suitable implant sites, thereby improving the success rate of the procedure. PURPOSE: The aim of this study was to evaluate a correlation between bone density measured preoperatively with computerized tomography and histologically measured bone density by bone biopsy.
PATIENTS AND METHODS
Twenty seven patients were selected. All the patients were in good health, with no systemic disorder and additional bone graft. Preoperatively the patients underwent CT scanning to evaluate Houmsfield Unit(HU). Each patients wore a surgical template for implant placement. During surgery 2mm in diameter and 6mm in length specimens were taken. Histomorphometric analysis was performed using digitalized image analysis software Axiovision 4.3. Also, the Resonance frequency analysis(RFA) and insertion torque values were recorded.
RESULTS
The highest histomorphometric values was found in the posterior mandible 32.3+/-3.8, followed by 29.9+/-2.6 for the posterior maxilla, 29.4+/-2.6 for the anterior maxilla, 28.6+/-2.3 for the anterior mandible(p=0.214). The hounsfield unit was 989.2+/-258.1 in the posterior mandible, 845.0+/-241.5 in the anterior maxilla, 744.5+/- 92.6 in the anterior mandible, 697.3+/-136.9 in the posterior maxilla(p=0.045). This results may suggest that there are strong correlation between the histomorphometric values and hounsfield unit(gamma=0.760, p<0.05). The RF measurements were 81.9+/-2.4 ISQ in the posterior mandible, 79.0+/-1.4 ISQ in the anterior mandible, 78.3+/-4.6 ISQ in the posterior maxilla, 76.5+/-5.0 ISQ in the anterior maxilla(p=0.048). The insertion torque values was 43.2+/-4.2 Ncm in the posterior mandible, 42.0+/-0.0 Ncm in the anterior mandible, 41.3+/-4.1 Ncm in the posterior maxilla, 40.8+/-3.8 Ncm in the anterior maxilla(p=0.612). This results may suggest that there are statistical significance between the hounsfield unit and the insertion torque values(gamma=0.494, p<0.05), the histomorphometric values and the insertion torque values(gamma=0.689, p<0.05). But there was no correlation between histomorphometric values and ISQ. There was no statistical significance in age and gender effect on parameters.
CONCLUSIONS
There was significant correlations between bone density and implant stability parameters. The bone density measurements using preoperative CT may help clinicians to predict primary stability before implant insertion, which is associated with implant survival rates.