Quantification of volumetric absorption for absorbable implant using micro-CT

Abstract

Introduction: The purpose of the study was to quantify the VA (volumetric absorption) from the result of osseointegration in micro-CT analysis. We have developed a new method to evaluate the osseointegration and absorption of the absorbable implant using micro-CT images. The measurement was correlated with the histomorphometric analysis.

Methods: For the procedure, mandibular 2 and 4 premolars were extracted bilaterally from seven experimental dogs (beagle dog), and installed two PLA-TCP 30% implants on each side. For close examination, the implants with its surrounding tissue were dissected to safely remove implants from the figures in sequence of 4 week, 8 week, and 12 weeks lapse since the installation. Seven implants were damaged and excluded and total 21 implants samples were used for the analysis. From the Micro- CT scan images, the confidence connected segmentation, connected threshold segmentation, morphology operation and labeling algorithm were applied, and volumetric analysis was performed between bone and implant to measure the VBIC (Volumetric Bone-Implant contact) and VA(Volumetric Absorption). The implant slices were prepared by dissecting the center area of the sample tissues in axial direction for histomorphometric analysis of BIC (Bone-Implant contact) and BA (Bone Area).

Results: As a result, the mean of VA and VBIC increased significantly with an increase in the healing period (p<.01 ANOVA, p<0.05 the turkey's multiple comparison test) The BA and the BIC did increase over the implant installation time period, but the difference of mean did not show significant difference. After analyzing the correlation between the VBIC and the VA based on Micro-CT analysis (which showed significant difference previously), it showed significant difference in correlation 0.463.

Conclusions: A compare of two different methods for quantify of osseointegration, histomorphometric analysis was limited to the absorbable implant analysis because the absorbable implant change in the size. In contrast, VA of absorbable implant showed significant correlation with VBIC, and it has provided a new parameter for osseointegration evaluation. Therefore, quantification of VA is required to evaluate osseointegrationun of an absorbable implant besides the other existing methods.