Finite element comparison of the effect of absorbers' design in the surrounding bone of dental implants

Despite the high success rate achieved in current dental implantation, there are still important problems to solve like incomplete early osteointegration, bone damage, and long-term implant loosening. Highly compliant stress absorbers are a possible solution to these problems. Although several works examined the stress-strain distribution in bone without and with absorbers to show their favorable results, none of them analyzed their impact on long-term remodeling. Here, we analyze this effect by comparing the evolution of stress and bone mass density without and with different designs of absorbers with those of the healthy tooth. Several finite element models with ABAQUS, corresponding to each design considered, were built to obtain the mechanical conditions in bone and implant. Then a mechanobiological bone remodeling model that considers damage accumulation and its repair during the remodeling process was used to compute the bone density redistribution. This approach allows assessing both the short-term density loss and the relative micromovement between bone and implant. We analyze the stress distributions in both bone and implant as well as the relative micromovement of the implant. We also present the evolution of damage and bone volume fraction. These results show that the addition of absorbers can reduce the stress in the bone around the implant. The obtained results also show that using stress absorbers reduces damage in bone, while increasing the number of absorbers does not necessarily improves damage reduction. We conclude that using implants with a correct design of absorbers prevents damage and stress shielding, reducing implant loosening.