Biomechanical Basis for Bone Healing and Osseointegration of Implants in Sinus Grafts.

A thorough comprehension of the mechanisms controlling new bone formation and implant osseointegration after maxillary sinus floor elevation is crucial for aligning our treatment choices with biological principles and enhancing clinical outcomes. The goal of bone regeneration in sinus lift procedures is to provide a sufficient amount of newly-formed tissue to support implant osseointegration. However, it is still unclear whether there is a minimum quantity of vital bone within the newly-formed tissue required for effective support, though it is generally assumed that vital bone is essential for this process. The source and integration of new bone in maxillary sinus floor elevation procedures remain debated. Most clinical studies suggest a paramount role for sinus floor and bony walls, with a centripetal pattern of new bone formation, while conflicting reports exist regarding the osteogenic role of the Schneiderian membrane. The influence of mechanical input on peri-implant bone formation, mineralization, and maturation is significant, with bone remodeling regulated by mechanical strains generated during loading. Defining optimal loading for implants, particularly in sinus lift procedures, is challenging, as early loading may damage interfacial tissue, interfering with osteogenesis. Differences in osseointegration dynamics between native and augmented bone may arise from biological and mechanical factors, but also from patient-specific factors which should be evaluated in treatment planning. Factors to consider include sinus anatomy, patient and site-specific regenerative potential, and the selection of graft material that matches the osteogenic and mechanical requirements. Tailored approaches integrating patient-specific considerations and refined implant strategies will enhance predictability and longevity of treatment.