Introduction: Dental implants are standard prosthetics used to replace defective teeth. Despite their widespread use, over 5% of implants fail, for reasons that are not yet fully understood. To address this issue, it is crucial to gain a deeper understanding of the bone formation mechanisms at the bone tissue–implant interface. Factors contributing to implant failures may include locally elevated stresses around the implant, caused either by the surgical protocol or by chewing forces.In this study, we analyzed the effects of loading—through simulated chewing forces—and the surgical protocol on bone quality. Our investigation focused on the mechanosensitive osteocyte lacunar-canalicular network, bone formation, and the bone mineral density distribution in the jawbone surrounding titanium implants.

Methods: To investigate the effects of predrilling protocols (a standard dental practice) and loading on the success of dental implants, sheep were implanted with dental prosthetics following three different protocols. The control group underwent non-undersized predrilling and did not experience loading after implantation. In contrast, the NU-L group received non-undersized predrilling, and the implants were cyclically loaded with 50 N after implantation. The U-L group underwent undersized predrilling, followed by the same loading protocol (50 N).Quantitative backscattered electron microscopy images were acquired and segmented into two regions of interest: 0–100 µm (close) and 100 µm to the maximum of the image (far). We analyzed the following parameters: bone mass, mineralization, and osteocyte lacunar density using the software XamFlow. The data were then subjected to statistical analysis, including one-way and two-way ANOVA.

Results: Analysis of the mean calcium content, osteocyte lacunar density, and bone area fraction revealed higher mineralization both close to and far from the implant in the U-L group compared to the NU-L group. Additionally, there was a trend toward more bone being present close to the implant (0.06<p<0.07). The osteocyte lacunar density was significantly lower in the U-L group compared to the control group (p=0.047).

Discussion: We observed that most differences were localized within the 0–100 μm region, which is directly influenced by the mechanical forces induced by the implant on the bone tissue. The elevated bone mass and mean calcium content in the loaded group with undersized holes (U-L) indicates good adaptation of the bone to the implant. However, the lower osteocyte lacunae density suggests a potentially impaired osteocyte differentiation during bone formation.