Dental extraction following zoledronate, induces osteonecrosis in rat's jaw.
BACKGROUND
Bisphosphonate-Related Osteonecrosis of the Jaw (BRONJ) is clinically characterized by the presence of exposed bone in the oral cavity that persists for more than eight weeks. Previous attempts to establish an animal model have not sufficiently considered disease features. Our aim was to establish an inexpensive and replicable animal model that develops BRONJ in a short time.


METHODS
Thirty-two male Wistar rats were randomly divided into two groups: control and experimental. In the experimental group, we administered 0.06mg/kg intraperitoneal dose of zoledronic acid (ZA) 7 and 14 days prior to maxillary second molar extraction. At two, four and six weeks after tooth extraction, the animals were euthanized, and we dissected the maxilla following histological procedures. We stained serial slides with hematoxylin and eosin and Masson's trichrome. The samples were harvested for macroscopic, radiologic and histological evaluation of bone changes.


RESULTS
At two weeks postextraction, we observed exposed necrotic bone in dental socket areas in experimental groups. Radiological analysis revealed osteolytic lesions accompanied by extensive destruction and sequestrum formation in the same group. Histological examination confirmed the absence of necrotic bone in control groups in contrast with the experimental groups. The percentage of empty lacunae and the number of osteoclasts and the necrotic bone area were significantly increased (p<0.05) in the experimental groups.


CONCLUSIONS
The animal model using ZA administration to prior dental extraction successfully mimicked human BRONJ lesions. Also, the model was easily replicated, inexpensive and showed different features than other previous BRONJ models.
Laboratorio de Patología Clínica y Experimental, Facultad de Odontología, Universidad Nacional Autónoma de México Circuito Institutos s/n, Ciudad Universitaria, 04510 Coyoacán, D. F. México, ximena_vidal_g@comunidad.unam.mx.
X
X
Vidal-Gutiérrez
J-F
JF
Gómez-Clavel
L-A
LA
Gaitán-Cepeda
D000818:Animals; D059266:Bisphosphonate-Associated Osteonecrosis of the Jaw / Q000209:etiology*; D050071:Bone Density Conservation Agents / Q000009:adverse effects*; D004164:Diphosphonates / Q000009:adverse effects*; D004195:Disease Models, Animal; D007093:Imidazoles / Q000009:adverse effects*; D008297:Male; D011183:Postoperative Complications / Q000209:etiology*; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D014081:Tooth Extraction; D000077211:Zoledronic Acid
D050071:Bone Density Conservation Agents; D004164:Diphosphonates; D007093:Imidazoles; D000077211:Zoledronic Acid