Host Modulation Therapy: A Novel Approach In The Treatment Of Periodontal Diseases

摘要

The primary etiology of periodontal diseases and chronic inflammation around dental implants is a bacterial infection. In essence, a gram negative infection of the pocket is necessary, but not sufficient to induce periodontal disease initiation or progression. Ultimately, it is the host’s reaction to the presence of the bacteria that mediates tissue destruction. Since the destruction of periodontal tissue is believed to be due to the host response, it is logical to consider therapeutic approaches that modulate the host response in addition to antibacterial approaches in the management of periodontitis and peri-implant disease.A number of host modulatory agents have been investigated which include the nonsteroidal anti-inflammatory drugs, subantimicrobial-dose doxycycline (SDD), and bisphosphonates. Introduction The primary etiology of periodontal diseases and chronic inflammation around dental implants is a bacterial infection.(1) In essence, a gram negative infection of the pocket is necessary, but not sufficient to induce periodontal disease initiation or progression. Ultimately, it is the host’s reaction to the presence of the bacteria that mediates tissue destruction. This response can be influenced by environmental (e.g., tobacco use), acquired (e.g., systemic disease), and genetic risk factors. Since the destruction of periodontal tissue is believed to be due to the host response, it is logical to consider therapeutic approaches that manipulate the host response in addition to antibacterial approaches in the management of periodontitis and peri-implant disease.Host response modulation is a term which has been introduced to the dental profession relatively recently.(2) The rationale behind this approach is to aid the host in its fight against infectious agents by supplementing the natural inherent defense mechanisms or to modify its response by changing the course of inflammatory systems. Compared to other weapons against infection, host response modulation potentially has fewer side-effects, is not invasive, and does not require complicated application methods.(3) Host response modulation is routinely practiced by our medical colleagues, who use host modulation strategies in the treatment of disorders such as rheumatoid arthritis and osteoporosis. (2) Over the last two decades, a variety of pharmacological agents have been studied for a possible role as host modulators in the management of periodontal disease. These include nonsteroidal anti-inflammatory drugs, bisphosphonates and the tetracycline family (and their chemically modified analogues(4)). Newer agents that have the potential to be of benefit in periodontal treatment include anti-cytokine drugs e.g. infliximab (5) (which have successfully been used in the treatment of rheumatoid arthritis), soluble cytokine blockers and lipoxins.(6) Pathogenesis of Periodontal Disease Periodontitis, initiated by plaque bacteria is characterized by destruction of the periodontal ligament and bone. Alveolar bone resorption occurs as a result of uncoupling of the normally balanced processes of bone resorption and bone formation. Cytokines, chemokines and prostaglandins have been identified as regulators of the immune-inflammatory process in periodontitis. Cytokines (especially interleukin-1 and tumor necrosis factor-α) can induce bone resorption indirectly by promoting the differentiation of osteoclast precursors and by activating osteoclasts.(6)The purpose of host modulatory therapy is to restore balance between, on the one hand, pro-inflammatory mediators and destructive enzymes, and, on the other hand, anti-inflammatory mediators and enzyme inhibitors. (Fig. 1)