An animal model is essential to investigate the pathophysiology of BRONJ and to explore prevention and management strategies to be tested subsequently with clinical trials1. Even if thirty years ago Gotcher et al. reported areas of necrotic alveolar bone protruded and exposed in the oral cavity in rats treated with dichloromethylene diphosphonate2, only in the last five years different animal models, particularly rodens, were used to study the association between osteonecrosis of the jaws and bisphosphate (BF)3. Rats are the most used animals because they present several advantages: are easy to manage with, allows experimental protocols with high number of animals and the process of bone healing after tooth extraction is well known. On the other side some disadvantageous aspects are evident: the healing capacity of rodens are higher compared to human beings and the small dimension of these animals make the oral surgical procedures more difficult.
The aim of this study was to critically review the recent literature on BRONJ in rat models.
Relevant articles were retrieved from MEDLINE/Pubmed database and by hand-searching in bibliographies. Thirty seven studies published from February 2009 to March 2014 were selected.
The incidence of BRONJ in rats treated with BF ranges from 0 to 100% depending on different factors: BF exposure (type, doses, duration), surgical trigger events (tooth extraction, implant insertion, creation of soft tissue surgical wound or surgical bone defect), systemic co-factors (diabetes, vit D deficency), local infection (periodontitis, periapical infection) and associated drugs (corticosteroids, antibiotics, teriparatide). Some preventive strategies tested gave promising results.
The analysis of the literature demonstrate that BRONJ in rats, like in humans, is mainly associated with high potency amino BF combined with dento-alveolar surgical events and/or other predisposing factors, in particular corticosteroids.
References
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