Bone density assessment using CBCT is an efficient method and significantly correlated with implant stability parameters and Lekholm and Zarb index. Thus, it is possible to predict initial implant stability and possibility of immediate or early loading using CBCT scans prior to implant placement.

The aim of this clinical study was to evaluate whether preoperative bone density value derived from cone-beam computed tomography (CBCT) gives predictable data about primary and secondary stability characteristics of immediately loaded dental implants under different clinical variables. A total of 77 immediately loaded implants placed in 23 patients were included the study. Bone density values of the implant recipient sites were recorded using CBCT. The maximum insertion torque values (ITVs) of the implants were recorded using a digital torque meter during surgery. Resonance frequency measurements were taken using the Osstell Mentor at 4 time points; immediately after surgery (implant stability quotient [ISQ]0) and after 1 (ISQ1), 3 months (ISQ3), and 12 months (ISQ12) of loading. Data were analyzed statistically. The mean bone density and ITVs of all implants were 565 ± 81 and 36.8 ± 3.8 N · cm, respectively. The mean ISQ values were 73.6 ± 5.8 at baseline, 71.1 ± 6.5 after 1 month, 74.8 ± 5.6 after 3 months, and 76.6 ± 5.1 after 12 months of loading. Statistically significant differences were observed between ISQ0 and ISQ1 (P < 0.001), and ISQ0 and ISQ12 (P < 0.001), but not between ISQ0 and ISQ3 (P > 0.05). In regard to stability changes over time, statistically significant correlations were found between bone density values from CBCT and ISQ follow-up measurements, and between ITV and ISQ follow-up measurements in all examination periods. Thus, it is possible to predict primary and secondary stability characteristics of immediately loaded implants by using preoperative CBCT scan and perioperative ITV.

The peri-implant bone of early-loaded implants was significantly denser than that of immediate- and delayed-loaded implants, 1 year after placement. Density increment can be judged as the radiological findings of loaded-bone, which may also reduce the need for histomorphometric analysis of human biopsy to evaluate the bone reaction around the implants.

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