Chapter 1 Implant research update
With so much interest in dental implants around the world there is an enormous amount of research being reported into a wide range of topics. Here, Stephen Hancocks describes some of the most recent studies scanned from the literature and looks particularly at current thinking on bisphosphonates and implants. There has been considerable debate about the use of the class of drugs called bisphosphonates (BP) for some years now especially in relation to their propensity to mediate BP-related osteonecrosis of the jaws (BRONJ). The drugs are prescribed to help treat conditions in which there are disturbances of bone growth such as osteoporosis, osteitis deformans (Paget’s disease), bone metastasis from cancers and other conditions involving fragile, breakable bone. They work by inhibiting the digestion of bone by causing osteoclasts to undergo cell death, thereby slowing bone loss and undermining the usual homeostatic body balance of osteoblast and osteoclast activity which keeps bone in constant turnover. This has an obvious relevance to implant treatment which relies on continuing healthy bone metabolism and growth for implants to undergo successful osseointegration. Risk factors for developing osteonecrosis of the jaw that should be considered are: potency of bisphosphonate (this is highest for the drug zoledronate), route of administration – oral or intravenous, cumulative dose, duration and type of malignant disease, concomitant treatment, smoking and history of dental disease. NICE recommends that all patients should have a dental check-up (and any necessary remedial work should be performed) before bisphosphonate treatment, or as soon as possible after starting treatment. Patients should also maintain good oral hygiene, receive routine dental check-ups, and report any oral symptoms such as dental mobility, pain, or swelling, non-healing sores or discharge during treatment. Because of this, there has been disagreement as to whether it is safe to place implants in patients under BP therapy owing to the risk of developing BRONJ. For example The American Association of Oral and Maxillofacial Surgeons recommends that dental implants should be avoided in oncologic patients treated with intravenous BPs. Conversely, for patients receiving oral BPs, dental implant placement is not explicitly contraindicated even if a cautious approach is suggested.
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