Application of the break-even point to express the bone dynamics around implants.

Purpose: The aim of this study was to apply the break-even point concept to express the dynamics of bone formation and resorption around implants.
Methods: Published data on new bone and parent bone densities around implants from one human and three dog studies were selected and used for analysis. The break-even point (BEP) of the bone density (BD) was assessed. The BEP is the point at which, in a graph, the lines representing the formation of new bone and resorption of old bone intersect. BEP is expressed in time (x; days) of occurrence and percentage of bone (y; %) at which the break-even point occurs and illustrates the grade of bone modeling. The sooner the occurrence, the faster the bone formation in relation to the resorption of the old bone.
Results: In the marrow and cortical compartments, BEP of bone density occurred after 7.9 days (BD% 24.5%) and >30 days, respectively. Different surfaces presented similar BEP, ranging between 9.7 and 11.2 days (BD% 19.1-22.5%). BEP at implants installed in the human maxilla occurred after 29-30.4 days (BD% 28.3-29.6%).
Conclusion: The present study showed that the parameters used to express the break-even point can provide information on the influence of the model used, surface characteristics, and bone quality on bone modeling/remodeling around implants.
(© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)