Estrogen treatment and periodontal disease progression: an experimental study in ovariectomized rats
TL;DR: Investigation of different periods of estrogen replacement therapy onset on the progression of experimental periodontitis in ovariectomized rats indicated that estrogen-deficient state may not have a direct effect on the alveolar bone adjacent to the maxillary second molar roots.
Abstract: The aim of this study was to investigate different periods of estrogen replacement therapy onset on the progression of experimental periodontitis in ovariectomized rats. MATERIAL AND METHODS: Sixty five female Wistar rats were ovariectomized and divided into two groups, experimental and control that received 17s estradiol or vehicle, respectively. Each group was subdivided into five subgroups that started the treatment immediately, one, two, three and four weeks after the ovariectomy. A month after ovariectomy, a cotton ligature was placed around the maxillary second molars. Thirty five days after ligature placement, the animals were killed. It was analyzed the macroscopic, radiographic, microscopic and histometric aspects of the periodontal area. RESULTS: The results indicated that estrogen-deficient state may not have a direct effect on the alveolar bone adjacent to the maxillary second molar roots. CONCLUSIONS: Under the conditions of this experiment, estrogen replacement therapy did not delay the progression of induced periodontitis. KEYWORDS: Estradiol; osteoporosis, ovariectomy; periodontal diseases.
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TL;DR: In this paper, the authors analyzed chronic alcohol consumption influence on induced periodontitis in rats presenting estrogen deficiency, and concluded that the association between estrogen deficiency and 20% ethanol was just relevant for sites without periodontal disease induction, since it induces stronger severity in the inflammatory process in the presence of the inflammatory cells scattered in the conjunctive tissue and of the disorientation of periodont ligament fibers.
Abstract: The immune system plays an important role in the pathogenesis of periodontal diseases. The host may modulate periodontal inflammatory reactions and it determines variances in the individual susceptibility and in the periodontal disease progression speed. Osteoporosis and alcoholism are described as risk indicators of periodontal disease among the systemic acquired factors. Objective: The current study aims to analyze chronic alcohol consumption influence on induced periodontitis in rats presenting estrogen deficiency. Material and Methods: Sixty rats approximately 90 days old were used in the experiment; they were divided into two groups: correlated surgery (OVZ) or surgical ovariectomy simulation (SHAM). Each group was divided into three subgroups: (C) control diet, (A) ethanol containing 20% liquid diet and (I) par-fed control diet. Thirty days after castration the diet and the experimental periodontitis induction were kept for 56 days. Interproximal regions between the first and the second lower left molar and the respective contralateral site without periodontal disease induction were assessed for inflammatory features. Results: Hormone deficiency resulted in important inflammatory changes concerning the meaning of SHAM-C and OVZ-C. The ethanol diet has resulted in inflammatory changes to both groups SHAM-A and OVZ-A in the absence of periodontitis, with also greater severity when combined with ovariectomy. Conclusion: It was concluded that the association between estrogen deficiency and 20% ethanol was just relevant for sites without periodontitis disease induction, since it induces stronger severity in the inflammatory process in the presence of the inflammatory cells scattered in the conjunctive tissue and of the disorientation of periodontal ligament fibers. Keywords Alcoholism; Osteoporosis; Ovariectomy; Periodontal disease.
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01 Jan 2016
TL;DR: It was concluded that the association between estrogen deficiency and 20% ethanol was just relevant for sites without periodontitis disease induction, since it induces stronger severity in the inflammatory process in the presence of the inflammatory cells scattered in the conjunctive tissue and of the disorientation of periodontal ligament fibers.
Abstract: The immune system plays an important role in the pathogenesis of periodontal diseases.The host may modulate periodontal inflammatory reactions and it determines variances in the individual susceptibility and in the periodontal disease progression speed. Osteoporosis and alcoholism are described as risk indicators of periodontal disease among the systemic acquired factors. Objective: The current study aims to analyze chronic alcohol consumption influence on induced periodontitis in rats presenting estrogen deficiency. Material and Methods: Sixty rats approximately 90 days old were used in the experiment; they were divided into two groups: correlated surgery (OVZ) or surgical ovariectomy simulation (SHAM). Each group was divided into three subgroups: (C) control diet, (A) ethanol containing 20% liquid diet and (I) par-fed control diet. Thirty days after castration the diet and the experimental periodontitis induction were kept for 56 days. Interproximal regions between the first and the second lower left molar and the respective contralateral site without periodontal disease induction were assessed for inflammatory features. Results: Hormone deficiency resulted in important inflammatory changes concerning the meaning of SHAM-C and OVZ-C. The ethanol diet has resulted in inflammatory changes to both groupsSHAM-A and OVZ-A in the absence of periodontitis, with also greater severity when combined with ovariectomy. Conclusion: It was concluded that the association between estrogen deficiency and 20% ethanol was just relevant for sites without periodontitis disease induction, since it induces stronger severity in the inflammatory process in the presence of the
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TL;DR: The data suggest that rat cortical bone might not be matured until 7.5 months of age and OVX have a great potential for weakening the bone quality of cortical bone and trabecular bone, respectively, and have an additive effect when combined.
Abstract: To study the long-term effect of aging, low calcium diet (LCD) and/or ovariectomy (OVX), and estrogen replacement therapy (+E) on rat bone quality of both trabecular and cortical bone, 150 female Wistar rats of 4.5 months were divided into baseline, sham-operation (sham), sham + LCD, OVX, OVX + E, OVX + LCD, OVX + LCD + E, and were observed for 3, 6, and 9 months postsurgery. The bone mineral density (BMD) of the lumbar spine L1–L4, the femoral neck, the midshaft, and the distal metaphysis were determined using dual-energy X-ray absorptiometry (DXA) in vitro. Biomechanical tests of the L1 vertebral body and the left femur were performed. The right femoral midshaft and neck were processed undecalcified for determining cross-sectional moments of inertia (CSMIs). BMD in all groups increased rapidly with aging in the femoral midshaft composed only of cortical bone at 3 months post-OVX and stabilized or decreased thereafter, but decreased at all observation periods in the distal femoral metaphysis, consisting mostly of trabecular bone. L1 maximum compressive strength and stiffness increased as a function of aging in sham and sham + LCD but not in OVX and OVX + LCD. The order of loss in BMD at all sites and in L1 strength and stiffness was: OVX + LCD > OVX > LCD. LCD reduced while OVX improved the total femoral area, CSMIs in the femoral midshaft, and the torsional strength. Estrogen treatment preserved BMD and prevented OVX-induced loss in L1 strength. The BMD and biomechanical properties were greater in OVX + E than in OVX + LCD + E. Loss in BMD and CSMIs was greater in the femoral neck than in the midshaft. The data suggest that rat cortical bone might not be matured until 7.5 months of age. It would be more appropriate to consider rats at peak bone mass as a model of mature rat and to perform OVX at that time. LCD and OVX have a great potential for weakening the bone quality of cortical bone and trabecular bone, respectively, and have an additive effect when combined. Estrogen prevents only OVX-induced bone loss.
92 citations
"Estrogen treatment and periodontal ..." refers background in this paper
...The wide divergence in the literature may be related to several factors such as the sample used, the method of analysis, the region, nutritional status, the time of analysis and the association with other drugs [2,14,18,26-30]....
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TL;DR: Bone loss and trabecular fragmentation had occurred in the rat mandibular alveolar bone by 1 year after ovariectomy, but only the difference in bone formation was of statistical significance.
Abstract: Objective. Trabecular structural changes in the jaw after long-term estrogen deficiency are not well understood. Therefore, we sought to observe the changes in rat alveolar bone for 1 year. Methods. Six-month-old female rats were ovariectomized (OVX) or underwent a sham operation. After 1 year, bone histomorphometry and a node-strut analysis were performed on the interradicular septum of the mandibular first molar by using micro computed tomography and confocal laser scanning microscopy. Statistical analysis was carried out by using analysis of variance. Results. The alveolar trabeculae of rats in the sham group had network structures, whereas the trabeculae of rats in the OVX group became fragmented. The trabecular bone volume, number, and thickness in the OVX group were significantly lower than those found in the sham group, and the trabecular separation was 4-fold higher in the OVX group than in the sham group. Bone resorptive and formative activity appeared to be moderately higher in the OVX group than in the sham group, but only the difference in bone formation was of statistical significance. Conclusion. By 1 year after ovariectomy, bone loss and trabecular fragmentation had occurred in the rat mandibular alveolar bone. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2003;95:495-502)
90 citations
"Estrogen treatment and periodontal ..." refers result in this paper
...To determine the long-term changes in bone turnover of the alveolar bone in an estrogendeficient condition, the same researches [11] investigated changes in OVX rats over a longer time after ovariectomy (1 year)....
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TL;DR: Oestrogen deficiency results in microarchitectural alterations of trabecular bone in both the mandible and the tibia within 16 weeks, which correlates with osteoporotic changes in the long bone.
Abstract: Objectives: To investigate the effects of oestrogen deficiency on the microarchitecture of trabecular bone in the mandible and the tibia and to test whether they are correlated. Methods: Twenty-four age-matched Lewis-Brown-Norway female rats underwent surgical intervention either to remove ovaries (ovariectomy, \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(n=12\) \end{document}) or to create a complementary control group (sham-operated, \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(n=12\) \end{document}). Sixteen weeks later, the animals were sacrificed and the left side of the mandibles and the tibias were scanned with high resolution micro-CT (15 μm). Multiple morphological measures including the ratio of bone volume/tissue volume, trabecular thickness, trabecular separation and st...
77 citations
"Estrogen treatment and periodontal ..." refers background in this paper
...[12] observed that ovariectomy significantly decreased the ratio of bone volume/ soft tissue volume and trabecular thickness, whilst significantly increasing trabecular separation and structure model index in both mandible and tibia....
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TL;DR: This study revealed regional differences in the mandibular bone decrease in OVX rats and demonstrated the advantage of pQCT in analyzing rat mandibULAR bone.
Abstract: INTRODUCTION: Although previous studies have shown that maxillary molar extraction in ovariectomized (OVX) animals causes mandibular loss of bone, it is still questionable as to whether estrogen deficiency affects mandibles with functional occlusion. MATERIALS and METHODS: To answer this question, 13-week-old female Sprague‐Dawley rats were bilaterally OVX or sham-operated. After 109 days, the bone mineral density (BMD) of the femurs and mandibles was measured using dual-energy X-ray absorptiometry (DEXA) and peripheral quantitative computed tomography (pQCT). RESULTS: In DEXA analysis, although the BMD of the total mandible of the OVX rats was similar to that of the sham-operated rats, the BMD of the condylar region in the OVX rats had decreased by 12.5%. In pQCT analysis, decrease in trabecular BMD of the mandibular bone was detectable but low in the molar region (maximal 13%), whereas no difference was seen in cortical BMD. In the femurs, the trabecular bone prominently decreased in OVX rats (30% decrease in pQCT analysis) as previously reported. CONCLUSION: This study revealed regional differences in the mandibular bone decrease in OVX rats. Although the mechanism of low susceptibility of the mandible to estrogen-deficient conditions remains unknown, it is likely that mechanical stress derived from functional occlusion is preventing bone loss in this pathological condition. Furthermore, this study demonstrated the advantage of pQCT in analyzing rat mandibular bone. Oral Diseases (2003) 9, 24–28
75 citations
"Estrogen treatment and periodontal ..." refers background in this paper
...The wide divergence in the literature may be related to several factors such as the sample used, the method of analysis, the region, nutritional status, the time of analysis and the association with other drugs [2,14,18,26-30]....
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TL;DR: Overall, the proximal tibia showed the earliest and greatest differences between OVX and Sham groups, and the 24‐week‐old group showed the best osteoporotic response.
75 citations
"Estrogen treatment and periodontal ..." refers background in this paper
...The wide divergence in the literature may be related to several factors such as the sample used, the method of analysis, the region, nutritional status, the time of analysis and the association with other drugs [2,14,18,26-30]....
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