Prevention Methods for Medication-Related Osteonecrosis of the Jaw: Microtomographic Evaluation

Objectives: To evaluate the effect of preventive therapies on medication-related osteonecrosis of the jaw in the alveolar repair process.
Methods: Seventy-two Wistar rats were used and treated with 0.035 mg/kg of zoledronic acid and subsequently submitted to the extraction of the lower right molars. After extraction, the animals were divided into 9 groups (n=8), GS (Sham - did not receive zoledronate), GC (Clot), Gβ (β-tricalcium-phosphate), GD (10% doxycycline gel), GP (photo-dynamic therapy), GDβ, GPβ, GPD, and GPDβ. After 28 days of tooth extraction, the pieces were scanned in a Skyscan microtomographic to obtain bone volume (BV/TV), trabecular thickness (Tb.Th), separation (TB.Sp), and number (Tb.N) of trabeculae. Data were subjected to statistical analysis (one-way ANOVA, followed by tukey's post hoc, p < 0.05).
Results: All groups present higher means of BV/TV when compared to GS (42.17% ± 2.65) and the best result was GPDB, 69.85% ± 6.25, followed by GPD and GDB (64.62 ±0.13 and 64.69 ± 4.40) when compared to GC, GS, GP, and GPB (P < 0.05). In Tb.Th, GD presented 0.163 mm ± 0.015 (P = 0.043) when compared to GP, 0.111 mm ± 0.0070. As for Tb.N, GPD 5.53 mm ± 5.53 had a greater number of trabeculae, compared to GS, 3.68 mm ± 3.48 (P < 0.05). There was no difference for Tb.Sp (P=0.199). Qualitatively, GS demonstrated bone sequestration, while therapies allowed the repair process.
Conclusions: The therapies associated or not demonstrated to be effective in preventing osteonecrosis and the use of biomaterial and doxycycline demonstrated maintenance of alveolar volume.