A Comparative Radiographic Study Of Crestal Bone Changes About One-Stage Dental Implants

Methods: Vertical bitewing radiographs were taken of 8 patients with 13 implants using custom bite blocks and paralleling techniques at implant placement (baseline), 3, 6 and 12 months. Radiographs were digitized at 8-bit depth and 50µm resolution and analyzed using Image Tool® (UTHSCSA, San Antonio, TX 1998). The linear peri-implant crestal bone heights (LIN) on the mesial and distal aspects (26 surfaces) were measured on the digitized bitewing image from a coronal implant reference point to the most superior crestal bone/implant interface. Serial measurements were also obtained from images subtracted from the baseline image (DSR) using gamma correction, image re-registration and enhancement (Diagnostic Subtraction Radiography; Electro Medical Systems, Richardson, TX). Dimensional corrections were performed using known radiographic implant fixture measurements. Mean measurements were compared using ANOVA at an á priori level of significance p£0.05.

Results: Significant differences in peri-implant bone loss were found between modalities at each radiographic stage (3 months: LIN=1.57±1.26, DSR=2.18±0.96; 6 months: LIN=1.92±1.12, DSR=2.69±1.05; 12 months: LIN=2.64±0.86, DSR=3.27±1.24).

Conclusions: The results suggest that approximately 60% of peri-implant bone loss using this implant system occurs in the first 3 months after implant placement. DSR crestal bone loss measurements are significantly greater than LIN.