Perioperative Antibiotic Regimen in Rats Treated With Pamidronate Plus Dexamethasone and Subjected to Dental Extraction: A Study of the Changes in the Jaws

Purpose: Osteonecrosis of the jaws is a well-known condition associated with long-term bisphosphonate use. This study analyzed the prophylactic effect of antibiotic treatment in Sprague-Dawley rats treated with pamidronate plus dexamethasone and subjected to oral surgery in the form of dental extraction. Materials and Methods: One hundred twenty animals were included in a randomized prospective study. Animals in group I (n = 60) were treated with dexamethasone 1 mg/kg and pamidronate 3 mg/kg 3 times per week for 7, 14, and 21 days. All were subjected to right mandibular or maxillary molar extraction 8, 15, and 22 days after the start of dosing. Animals in group II (n = 60) received the same treatment except for the addition of penicillin 0.1 mL/kg per day for 3 days before and 4 days after extraction. Rats in the 2 groups were sacrificed 14 and 28 days after extraction. A clinical and histologic evaluation was performed. Results: In group I, osteonecrosis was documented in 18 cases (34.6%; affecting the upper and lower jaws in 10 and 8 cases, respectively). In group II, osteonecrosis was documented in 5 cases (9.61%; affecting the upper and lower jaws in 3 and 2 cases, respectively). The difference between the 2 groups was statistically significant (P = .002). Conclusions: The adoption of preventive measures (antibiotic prophylaxis) in invasive dental procedures results in a significant decrease in osteonecrosis of the jaws associated with bisphosphonate use. (C) 2011 American Association of Oral and Maxillofacial Surgeons J Oral Maxillofac Surg 69:2488-2493, 2011