Host Modulatory Therapy

Host modulatory therapy is a relatively new concept in the treatment and management of periodontitis. Host modulatory therapy attempts to reduce the destruction of periodontal tissues while stabilizing and even regenerating these tissues through modified host response, which is the reaction or defense mechanism of a living system. Traditionally, periodontitis has been battled by reducing the amount of bacteria in the oral cavity, through a variety of treatment methods. However, certain treatments, such as dental scaling and root planing, may provide unstable or unpredictable results, and innovations in treatment of periodontal disease are constantly arising. To effectively treat periodontal disease, therapies must strike a balance between two important processes: first, the amount of bacteria and the number of inflammatory events in the periodontal tissue must be reduced; second, inflammation and destructive processes must be resolved. With these balanced goals in mind, dental health professionals seek to optimize treatments by reducing inflammation and inhibiting destructive events and processes in the periodontal tissue, resulting in increased stability of the periodontal tissues following mechanical treatments like dental scaling and root planing. Instead of treating the bacteria present in the oral cavity’s host-bacteria interaction, host modulatory therapy serves to treat the host’s side of the dynamic.

There are multiple different agents that may be used in host modulatory therapy. One potential host modulatory therapy agent is non-steroidal anti-inflammatory drugs, or NSAIDs, which inhibit prostaglandin formation that is prompted in response to bacteria. This prostaglandin is the upregulator of bone resorption and exists in higher levels in patients with periodontal disease. Bisphosphonates, drugs that help prevent the loss of bone density, may be used to strengthen the bones of the jaw, which are prone to resorption when periodontitis is present. Sub antimicrobial doxycycline, at a dosage of 20 mg, has been approved as a supplemental treatment to dental scaling and root planing in the treatment of chronic periodontitis. Prolonged treatment of twice-daily doses for a span of three months to nine months can inhibit the cytokines and osteoclasts that support bone resorption, rather than serving an antimicrobial purpose.

Enamel matrix proteins help improve wound healing and stimulate lost-bone regeneration, also restoring the periodontal ligament and cementum. They do this by biomimetically stimulating the tissues surrounding the teeth, leading to the regeneration of these tissues. These effects make them valuable tools to restore the entire periodontal attachment apparatus. Emdogain, an extract of tooth material derived from fetal pigs, is currently the only approved enamel matrix protein host modulatory agent. Growth factors, naturally occurring substances that stimulate the proliferation and possibly the differentiation of cells and also help heal wounds, may be used similarly in host modulatory therapies. These growth factors are usually made of secreted proteins or steroid hormones, depending on the types of tissues to be treated. Bone morphogenetic proteins make up a group of growth factors known as metabologens. These bone morphogenetic proteins were originally used to induce the growth of bone and cartilage and are now found to have a more significant role in the architecture of the tissues of the entire body.