Diminished Progression of Periapical Lesions with Zoledronic Acid in Ovariectomized Rats.
BACKGROUND
The aim of this study was to investigate the effects of systemically administered zoledronic acid (ZOL) on the progression of periapical lesions in estrogen-deficient rats.


METHODS
Female Wistar rats were divided into the following groups: SHAM-veh, sham surgery treated with vehicle (physiological saline); OVX-veh, ovariectomy treated with vehicle; SHAM-ZOL, sham surgery treated with ZOL; and OVX-ZOL, ovariectomy treated with ZOL. Vehicle or ZOL was administered intravenously once a week for 4 weeks. The pulp of the mandibular first molar of all rats was exposed to the oral environment to induce a periapical lesion, and the lesions were analyzed after 7 and 30 days. The mandibles were examined by micro-computed tomographic imaging and histopathologic, histometric, and immunohistochemical analyses.


RESULTS
Histopathologically, the OVX-veh group had more severe inflammation and bone loss and a larger number of cells that were positive for tartrate-resistant acid phosphatase compared with the SHAM-veh and OVX-ZOL groups; the SHAM-veh and OVX-ZOL groups were similar to each other. The SHAM-ZOL group had the lowest magnitude of these conditions. Tomographically, the OVX-veh group had greater bone loss than the other groups at both time points. The SHAM-veh, SHAM-ZOL, and OVX-ZOL groups had similar bone loss at both time points. In the sagittal section on day 30, the SHAM-ZOL group had lower bone loss compared with the SHAM-veh and OVX-ZOL groups.


CONCLUSIONS
The hypoestrogenic condition aggravates the progression of periapical lesions. ZOL therapy may help contain bone destruction of periapical lesions.
Division of Dentistry and Oral Surgery, Department of Sensory and Locomotor Medicine, Faculty of Medical Sciences, University of Fukui, Fukui, Japan; Department of Endodontics, Araçatuba School of Dentistry, Universidade Estadual Paulista, Araçatuba, São Paulo, Brazil.
Marcelo Tadahiro
MT
Wayama
Division of Dentistry and Oral Surgery, Department of Sensory and Locomotor Medicine, Faculty of Medical Sciences, University of Fukui, Fukui, Japan.
Hitoshi
H
Yoshimura
Department of Regenerative Oral Surgery, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan.
Seigo
S
Ohba
Division of Dentistry and Oral Surgery, Department of Sensory and Locomotor Medicine, Faculty of Medical Sciences, University of Fukui, Fukui, Japan.
Hisato
H
Yoshida
Division of Dentistry and Oral Surgery, Department of Sensory and Locomotor Medicine, Faculty of Medical Sciences, University of Fukui, Fukui, Japan.
Shinpei
S
Matsuda
Division of Dentistry and Oral Surgery, Department of Sensory and Locomotor Medicine, Faculty of Medical Sciences, University of Fukui, Fukui, Japan.
Junichi
J
Kobayashi
Division of Tumor Pathology, Department of Pathological Sciences, Faculty of Medical Sciences, University of Fukui, Fukui, Japan.
Motohiro
M
Kobayashi
Department of Endodontics, Araçatuba School of Dentistry, Universidade Estadual Paulista, Araçatuba, São Paulo, Brazil.
João Eduardo
JE
Gomes Filho
Division of Dentistry and Oral Surgery, Department of Sensory and Locomotor Medicine, Faculty of Medical Sciences, University of Fukui, Fukui, Japan. Electronic address: sano@u-fukui.ac.jp.
Kazuo
K
Sano
D000818:Animals; D050071:Bone Density Conservation Agents / Q000627:therapeutic use*; D001862:Bone Resorption; D004164:Diphosphonates / Q000627:therapeutic use*; D018450:Disease Progression; D005260:Female; D007093:Imidazoles / Q000627:therapeutic use*; D007150:Immunohistochemistry; D010020:Osteonecrosis / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000473:pathology; D010052:Ovariectomy; D010485:Periapical Periodontitis / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000473:pathology; D017208:Rats, Wistar; D055114:X-Ray Microtomography; D000077211:Zoledronic Acid
D050071:Bone Density Conservation Agents; D004164:Diphosphonates; D007093:Imidazoles; D000077211:Zoledronic Acid
Bisphosphonate; estrogen deficiency; osteonecrosis