Biomechanics of Osseointegration of a Dental Implant in the Mandible Under Shock Wave Therapy: In Silico Study.

The most time-consuming aspect of dental prosthesis installation is the osseointegration of a metal implant with bone tissue. The acceleration of this process may be achieved through the use of extracorporeal shock wave therapy. The objective of this study is to investigate the conditions for osseointegration of the second premolar implant in the mandibular segment through the use of a poroelastic model implemented in the movable cellular automaton method. The mandibular segment under consideration includes a spongy tissue layer, 600 µm in thickness, covered with a cortical layer, 400 µm in thickness, and a gum layer, 400 µm in thickness. Furthermore, the periodontal layers of the roots of the first premolar and first molar were considered, while the implant of the second premolar was situated within a shell of specific tissue that corresponded to the phase of osseointegration. The model was subjected to both physiological loading and shock wave loading across the three main phases of osseointegration. The resulting fields of hydrostatic pressure and interstitial fluid pressure were then subjected to analysis in accordance with the mechanobiological principles. The results obtained have indicated that low-intensity shock wave therapy can accelerate and promote direct osseointegration: 0.05-0.15 mJ/mm in the first and second phases and less than 0.05 mJ/mm in the third phase. In comparison to physiological loads (when bone tissue regeneration conditions are observed only around the implant distal end), shock waves offer the primary advantage of creating conditions conducive to osseointegration along the entire surface of the implant simultaneously. This can significantly influence the rate of implant integration during the initial osteoinduction phase and, most crucially, during the longest final phase of bone remodeling.