Hyun Ju Kim1, Kyoung-Hwa Kim2, Yong-Moo Lee2, Young Ku2, Seong-Joo Heo3, In-Chul Rhyu2, Yang-Jo Seol2. 1. Department of Periodontics, Seoul National University Dental Hospital, 101 Daehakno, Jongno-gu, Seoul, 03080, Korea. 2. Department of Periodontology and Dental Research Institute, School of Dentistry, Seoul National University, 101 Daehakno, Jongno-gu, Seoul, 03080, Korea. 3. Department of Prosthodontics and Dental Research Institute, Seoul National University Dental Hospital, School of Dentistry, Seoul National University, 101 Daehakno, Jongno-gu, Seoul, 03080, Korea.
Abstract
BACKGROUND: The aim of this study was to seek the critical time for impairment of alveolar bone regeneration after ovariectomy (OVX) in rats. METHODS: A total of thirty-two female rats were used. Test group rats were divided into a 2M group (n = 8), a 3M group (n = 8) and a 4M group (n = 8) according to the duration from OVX to defect creation. Bilateral OVX was performed in all test groups, and a sham operation was performed in the control group (n = 8). Drill-hole defects (1.5 mm diameter, 2 mm length) were created on both sides of the maxilla. All rats were euthanized 2 and 4 weeks after the surgery. Microcomputed tomographic, histological and histomorphometric analyses and in vitro experiments were performed. RESULTS: The 4M group showed significantly less new bone formation and a lower bone mineral density than the other groups in the microcomputed tomographic analysis. The histomorphometric analysis also revealed that the 4M group showed significantly less new bone formation than the control and 2M groups. The rats in the 4M group showed significantly higher alkaline phosphatase (ALP) expression levels and a larger number of calcified nodules than rats in the other groups, whereas osteoclastic activity was significantly lower in the 4M group than in the other groups. CONCLUSIONS: The critical time for impairment of alveolar bone regeneration was 4 months after OVX in rats. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
BACKGROUND: The aim of this study was to seek the critical time for impairment of alveolar bone regeneration after ovariectomy (OVX) in rats. METHODS: A total of thirty-two female rats were used. Test group rats were divided into a 2M group (n = 8), a 3M group (n = 8) and a 4M group (n = 8) according to the duration from OVX to defect creation. Bilateral OVX was performed in all test groups, and a sham operation was performed in the control group (n = 8). Drill-hole defects (1.5 mm diameter, 2 mm length) were created on both sides of the maxilla. All rats were euthanized 2 and 4 weeks after the surgery. Microcomputed tomographic, histological and histomorphometric analyses and in vitro experiments were performed. RESULTS: The 4M group showed significantly less new bone formation and a lower bone mineral density than the other groups in the microcomputed tomographic analysis. The histomorphometric analysis also revealed that the 4M group showed significantly less new bone formation than the control and 2M groups. The rats in the 4M group showed significantly higher alkaline phosphatase (ALP) expression levels and a larger number of calcified nodules than rats in the other groups, whereas osteoclastic activity was significantly lower in the 4M group than in the other groups. CONCLUSIONS: The critical time for impairment of alveolar bone regeneration was 4 months after OVX in rats. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
Entities:
Keywords:
X-ray microtomography; bone density; osteoporosis; ovariectomy