Bone decay and beyond: how can we approach it better.

Osseo-degeneration is a disorder related to several factors, that may lead to the disruption of several skeletal regions providing support, such as the femur head, the vertebrae and the alveolar bone. The functional condition can be restored by means of grafting procedures, using different materials: calcium powder, xenografts, ceramics and metals. Such procedures aim at reforming an adequate bone volume and strength, that is necessary to support loading forces. Bone regeneration requires that the basic biological principles of osteogenesis, osteoinduction, osteoconduction and biocompatibility are followed. The success of regenerative procedures may depend on the inner structural, mechanical and metabolic condition of the host's bone on which implants should be inserted, on the surgical technique, and on the biomaterial used. Among these, the aging process of the patient appears to be relevant. It can be associated with metabolic disease leading to systemic functional decay, which involves a gradual steady decline of hormonal, immune function and osteo-metabolic activity. The latter can affect the positive outcomes of bone reconstruction and implant therapy. This review will analyze the biological and physiological factors involved in the bone tissue break-down, such as the influences from gut microbiome unbalance and the consequent metabolic, endocrine, immune dysfunctions, the surgery procedures and the quality of the grafting material used. The decline of bone architecture and strength should be corrected by using an appropriate clinical regenerative approach, based on a bio-endocrine, metabolic and immunologic know-how. The final characteristics of the regenerated bone must be able to support the loading forces transmitted by the implants, independent of the body location, and should be individualized according to the different condition of each patient.