Fractal analysis evaluation of bone texture after implant loading

Objectives: Fractal analysis is a texture analysis which describes complex shapes and structural patterns. It may be applied to radiographic images to detect changes in bone architecture. It was evaluated the maxilar/mandibular bone texture before and after implant loading in a group of patients by using fractal analysis. Methods: Twenty-nine patients with fully integrated implants (edentulous areas) were enrolled. The implants had minimum integration time of 5 months. Periapical radiographies using a CCD sensor plus positioner (Sopix/Sopro/France) were taken before implant loading (control image) and at least 3 months post-loading (test image). There was an average of 6 months between the two radiographies and the positioner allowed a minimal geometrical difference between them. All procedures for calculation of the fractal dimension were performed using Image J software (NIH/USA). The regions of interest (ROI) included the trabecular bone around the implants. The implant screws and anatomical structures were not included in the ROIs. The fractal dimension (FD) was calculated by using box counting function after skeletonization. FD values of ROIs were analyzed statistically using Paired t-test (alpha 0.05). Results: There was no significant difference before and after implant loading (p=0.069) for the FD values. Conclusions: The methodology used was not able to show statistically difference between control and test images. It is possible that the time/occlusal load elapsed between the radiographies was not enough to show any difference in the trabecular bone texture according to fractal analysis applied.