Bone tissue is a dynamic system in which the net balance between resorption and apposition defines the final osseous form. This process occurs in minute asynchronous foci and results from a cascade of activations, cooperations and inhibitions of specialized cells (osteoblasts and osteoclasts). The alveolar bone resorption due to periodontal disease is a complex and dynamic chain reaction in which both osteoclasts and osteoblasts have a role in the hormonal interactions occurring during the course of the resorption activity. Both microbial and host factors as prostaglandins, endotoxins and lipoteic acid seems to be able in activating bone resorption. However bone resorption can be interchanged with repair formative episodes, more or less intense, which can delay the destructive process.