雌激素对绝经后妇女牙槽骨吸收的影响机制

雌激素水平能影响牙槽骨吸收,其生物学效应可能主要通过2种途径实现:1)直接通过细胞表面的雌激素受体介导,主要包括经典的基因组途径和雌激素受体介导的非基因组途径;2)调节细胞因子表达,通过它们的作用调节骨代谢,本文就雌激素作用于牙槽骨影响其代谢的这2种可能途径的研究进展作一综述.     

雌激素对骨质疏松大鼠牙槽骨改建及IL-1表达的影响

目的：探讨雌激素对骨质松牙槽骨改建中ＩＬ－１的表达与分布的影响及意义。方法：在建立ＳＤ大鼠骨质疏松模型的基础上,用免疫组化染色方法,观察ＩＬ－１在骨质疏松以及雌激素治疗后的牙槽骨中的表达变化。结果：ＩＬ－１在骨质疏松牙槽骨中有较强的表达,阳性反应主要分布于破骨细胞,部分成骨细胞及骨细胞中,而在用雌激素治疗骨质疏松组中,ＩＬ－１的阳性表达程度明显下降。     

甲状旁腺激素与雌激素对去势雌性大鼠牙槽骨代谢的影响

目的 观察甲状旁腺激素与雌激素单独和联合应用对去势雌性大鼠牙槽骨代谢的影响。方法选用4月龄雌性Wistar大鼠66只,分成两组,分别为伪手术组（n=18）和去势组（n=48）。8周后各处死8只证实骨质疏松造模成功。剩余的伪手术组（A组,n=10）Wistar大鼠作为对照;将剩余的去势组Wistar大鼠随机分成4组,分别为去势组（B组）、去势加雌激素组（C组）、去势加甲状旁腺激素组（D组）、去势加雌激素和甲状旁腺激素组（E组）,每组10只。A组和B组注射生理盐水（1 mL·kg-1）;C组注射苯甲酸雌二醇（10 μg·kg-1）; D组注射甲状旁腺激素（20 μg·kg-1）;E组注射苯甲酸雌二醇（10 μg·kg-1）和甲状旁腺激素（20 μg·kg-1）。隔日腹腔注射1次,用药8周。治疗后处死大鼠并测定牙槽骨骨密度,观察每组大鼠骨组织形态计量学参数及血清钙、磷、碱性磷酸酶（ALP）水平。结果去势手术8周后,去势组大鼠牙槽骨密度明显低于伪手术组（P<0.05）。用药8周后,C、D、E组骨密度、骨小梁面积百分比（%Tb.Ar）、骨小梁宽度（Tb.Th）和骨小梁数量（Tb.N）较B组均有明显提高,其中E组提高最明显（P<0.05）。各组血清钙磷值无明显改变（P>0.05）,B组ALP值较A组明显升高（P<0.05）。结论间歇性、小剂量注射甲状旁腺激素能增加去势大鼠牙槽骨的骨密度和改善骨结构,与雌激素联合使用对骨质疏松的治疗有协同作用。     

雌激素缺乏对大鼠实验性牙周炎骨吸收的影响

目的评价雌激素缺乏及雌激素替代治疗(ERT),对大鼠实验性牙周炎牙槽骨吸收的影响。方法选取Wistar雌性大鼠24只,随机分成三组,Ⅰ组假手术组(n=8)、Ⅱ组卵巢摘除(OVX)组(n=8),Ⅲ组OVX 雌激素给药组(n=8)。21天后,将大鼠一侧上颌第一磨牙的牙周结扎,60天后,处死动物,取材,测得双侧磨牙的骨吸收量。结果结扎侧Ⅱ组的骨吸收量显著高于Ⅰ、Ⅲ组,有统计学意义,P<0.05;Ⅰ、Ⅲ组相比无统计学差别,P>0.05。结论ERT可能有效地防止雌激素缺乏状态下的牙槽骨吸收,但对于伴有菌斑刺激引起的牙周炎,ERT尚不能有效地阻止牙槽骨的吸收。     

Alendronate阻止牙槽骨骨吸收的实验研究

目的：评价双膦酸盐Alendronate抑制牙槽骨骨吸收的作用。方法：建立骨质疏松及牙槽骨吸收动物模型,建模术后六周,给实验组皮下注射Alendronate每周3次,共6周;用血生化指标骨生物力学、骨密度测量、组织形态学等方法进行药效评价。结果：股骨骨密度对照组与用药组相比明显降低（P＜0．01）;血清碱性磷酸酶对照组与用药组相比明显升高（P＜0．01）;骨生物力学各项指标实验组与对照组也有明显差异。组织形态学：实验组牙龈轻度炎症,牙槽骨水平吸收与对照组相比明显减少;对照组牙龈乳突炎症明显,上皮钉突增生。炎细胞浸润,牙槽骨明显水平吸收。结论：Alendronate治疗骨质疏松有明显的疗效,能够增加骨量,阻止骨丢失;对病理性牙槽骨骨吸收有显著的治疗作用。     

影响无牙颌牙槽骨吸收的某些因素的初步研究

本文用γ射线法测量了66例(女性28例,男性38例)无牙颌患者的骨矿含量;用头影测量法测量了无牙颌患者的牙槽骨吸收程度,同时测量血钙、磷、镁、碱性磷酸酶。对骨矿含量,钙磷乘积、碱性磷酸酶、年龄,性别、戴全口义齿时间、缺失全口牙的主要原因、牙槽骨吸收程度等因素作了多元逐步回归分析和主成份分析。结果表明:1.牙槽骨吸收受多种因素的共同影响,全身因素的作用值得重视;2.牙槽骨吸收与骨质疏松有一定的关系;3.无牙颌患者的骨重建作用可能活跃;4.头影测量法仍是目前研究牙槽骨吸收量的好方法。     

雌激素对骨质疏松大鼠牙槽骨改建过程中IL-1表达的影响

目的:研究雌激素对骨质疏松牙槽骨改建过程中白细胞介素-1(IL-1)的分布及表达的影响,探讨雌激素对骨质疏松牙槽骨改建影响的机制。方法:利用大鼠卵巢切除术制成骨质疏松模型,并运用免疫组化染色方法及半定量分析,观察IL-1在骨质疏松及雌激素治疗后的牙槽骨中的表达变化。结果:IL-1在骨质疏松牙槽骨中的表达明显增强,阳性反应主要分布于破骨细胞、部分成骨细胞中,而经雌激素治疗后,IL-1的阳性表达明显下降。结论:雌激素对骨质疏松大鼠牙槽骨中IL-1的表达有明显的抑制作用。     

单根牙牙槽骨吸收度与最大He力关系的研究

目的：研究单根牙牙槽骨吸收程度与最大He力的关系。方法：选择37例牙周病患者，710个单根牙，记录其前牙超覆He情况，拍摄牙片，测量每个受试牙的牙槽骨吸收程度和最大He力，结果：最大He力值因个体间和牙位琐存在明显差异。当左右同名牙牙槽骨高度相近时，最大He力值相近，最大He力值与牙槽骨吸收程度有着明显的相关性。牙槽骨吸收程度增加，最大He力降低。牙周病易于导致前牙覆He深，超He大的He型。结论：牙槽骨高度影响最大He力，牙周病将导致He的异常及咀嚼功能受到损害。     

无牙颌下颌牙槽骨吸收的纵向研究：Ⅰ.确定牙槽骨吸收程度的方…

通过比较１７例无牙颌患者５年前后的头侧位Ｘ线片，发现下颌角点、髁状突顶点、喙突顶点构成的三角形面积Ｓ１５年前后变化无显著性差异，提示Ｓ１－Ｓ２／Ｓ１的值比Ｓ２更准确地反映牙槽骨的吸收程度。     

Intermittent administration of parathyroid hormone ameliorated alveolar bone loss in experimental periodontitis in streptozotocin-induced diabetic rats

ObjectiveIntermittent administration of parathyroid hormone (PTH) has been demonstrated to have anabolic effects on bone metabolism and is approved for use in the treatment of osteoporosis. This study evaluates the role of intermittent PTH administration on alveolar bone loss in streptozotocin (STZ)-induced diabetic rats.DesignFifty male Sprague Dawley rats were randomly divided into the following five groups: (1) a control group (saline placebo without ligature and STZ injection), (2) a PTH group (PTH administration without ligature and STZ injection), (3) an L group (saline placebo with ligature), (4) an L + STZ group (saline placebo with ligature and STZ injection), and (5) an L + STZ + PTH group (PTH administration with ligature and STZ injection). PTH was administered at 75 μg/kg per dose four times a week for 28 days. Subsequently, all rats were sacrificed, and their mandibles were extracted for micro-computed tomography (micro-CT) scanning, as well as histological and immunochemical evaluation.ResultsMicro-CT scanning demonstrated the anabolic effect of PTH on alveolar bone metabolism in STZ-induced diabetic rats (P < 0.05), and histomorphometry indicated that PTH inhibited inflammation of the periodontium and increased the level of osteoblastic activity (P < 0.05). Immunochemical evaluation showed that rats subjected to both ligature placement and STZ injection had the highest receptor activator of nuclear factor kappa B ligand (RANKL)/osteoprotegerin (OPG) ratio and that PTH administration decreased this ratio.ConclusionIntermittent systemic PTH administration effectively reduced alveolar bone loss and ameliorated the manifestation of experimental periodontitis in STZ-induced diabetic rats.     

Low concentration alcohol intake may inhibit spontaneous alveolar bone loss in Wistar rats

Objective

The aim of the present study was to evaluate the influence of ethanol in low concentration (5%) in ligature-induced alveolar bone loss in Wistar rats.

Material and Methods

Thirty rats were randomly assigned to test and control groups (n = 15). Test group received a liquid diet containing ethanol 5% (vol./vol.) and standard rat chow. Control group received only tap water as the liquid diet and the same rat chow. In both groups, diet was delivered ad libitum. Alveolar bone loss was induced prior to the beginning of the study by means of ligatures placed around the upper second molars. The contra-lateral tooth remained as intra-group control. At the end of the nine weeks, the animals were killed and morphometric analysis of alveolar bone loss was performed by a blinded and calibrated examiner. Intra-group comparisons were performed by paired sample T-test and inter-group differences were compared by independent sample T-test (α = .05).

Results

Animals that drank ethanol in low concentration systematically presented less alveolar bone loss than the control group, regardless of the presence of ligature. Test group showed less alveolar bone loss (p = 0.04) in unligated teeth when compared to control group (0.32 ± 0.07 and 0.37 ± 0.07 mm, respectively). However, no significant difference (p = 0.14) was observed between Test and Control groups (0.78 ± 0.14 and 0.84 ± 0.18 mm, respectively) in ligated teeth.

Conclusion

The results of this study lead to the conclusion that low concentration alcohol intake did not affect the alveolar bone loss in ligature induced periodontal breakdown.     

侵袭性牙周炎牙槽骨吸收状况及相关因素分析

目的 评价未经治疗的侵袭性牙周炎(aggressive periodontitis,AgP)患者牙槽骨吸收状况并分析与牙槽骨吸收状况有关的因素,以期为临床提供参考.方法 对108例未经治疗的AgP患者[男45例,女63例;年龄≤25岁者34例(A组),＞25岁者74例(B组)]进行吸烟状况和教育背景的问卷调查,并测量全口牙邻面位点探诊深度(probing depth,PD,浅袋:PD=3、4 mm,中袋:PD=5、6 mm,深袋:PD≥7 mm);根据全口X线根尖片评价邻面牙槽骨吸收状况(轻、中、重度骨吸收).结果 实际共测量了2841颗牙.浅袋与轻度骨吸收(r=0.518,P=0.000)、深袋与重度骨吸收(r=0.366,P=0.000)均呈正相关;AgP患者男性轻、中、重度骨吸收牙数(分别为7.1±6.2、12.5±4.7、5.1±0.6)与女性(分别为8.7±6.3、12.9±4.8、4.2±0.5)差异无统计学意义(P值分别为0.707、0.671和0.413);B组中、重度骨吸收牙数(分别为13.6±4.2、5.2±3.7)显著多于A组(分别为11.0±5.5、3.6±3.5),P＜0.01;受过高等教育和未受高等教育者轻、中、重度骨吸收牙数差异无统计学意义(P值为0.314、0.862和0.407);吸烟是重度骨吸收AgP患者的危险因素之一(OR=1.961).结论 AgP患者PD与牙槽骨吸收程度相关;年龄和吸烟是影响AgP患者牙槽骨吸收的重要因素.     

Extracellular ATP is a key modulator of alveolar bone loss in periodontitis

Periodontal diseases are initiated by pathogenic bacterial biofilm activity that induces a host inflammatory cells immune response, degradation of dento gingival fibrous tissue and its detachment from root cementum. It is well accepted, that osteoclastic alveolar bone loss is governed exclusively through secretion of proinflammatory cytokines. Nevertheless, our findings suggest that once degradation of collagen fibers by MMPs occurs, a drop of cellular strains cause immediate release of ATP from marginal gingival fibroblasts, cell deformation and influx of Ca + 2. Increased extracellular ATP (eATP) by interacting with P2 × 7 purinoreceptors, present on fibroblasts and osteoblasts, induces generation of receptor activator of nuclear factor kB ligand (RANKL) that further activates osteoclastic alveolar bone resorption and bone loss. In addition, increased eATP levels may amplify inflammation by promoting leukocyte recruitment and NALP3-inflammasome activation via P2 × 7. Then, the inflammatory cells secrete cytokines, interleukin IL-1, TNF and RANKL that further trigger alveolar bone resorption. Moreover, eATP can be secreted from periodontal bacteria that may further contribute to inflammation and bone loss in periodontitis. It seems therefore, that eATP is a key modulator that initiates the pathway of alveolar bone resorption and bone loss in patients with periodontal disease. In conclusion, we propose that strain release in gingival fibroblasts aligned on collagen fibers, due to activity of MMP, activates release of ATP that triggers the pathway of alveolar bone resorption in periodontitis. We predict that by controlling the eATP interaction with its cellular purinoreceptors will reduce significantly bone loss in periodontitis.     

牙槽骨吸收与吸烟状况的研究

目的: 评价不同程度牙槽骨吸收的牙数与每日吸烟量和血浆中cotinine水平的关系。方法: 120名未治疗的慢性牙周炎患者,男 48,女 72,平均年龄 42. 3岁。根据自述的吸烟状况分组。116人检测了血浆cotin ine水平。根据骨吸收达根长的冠 1 /3、中 1 /3和根 1 /3, 牙槽骨吸收分为轻、中、重度骨吸收。结果:cotinine水平与自述的吸烟状况呈正相关(P<0. 001)。重度吸烟组较非吸烟组,中度骨吸收的牙齿数明显增多;而非吸烟组,无骨吸收的牙齿多(P值均<0. 001)。结论:吸烟>10支 /d是牙槽骨吸收牙数增加的重要危险因素。     

Effects of glucocorticoid-induced osteoporosis on bone tissue of rats with experimental periodontitis

ObjectiveTo evaluate the effects of osteoporosis induced by glucocorticoid (GIOP) on bone tissue of rats with experimental periodontitis (EP).Design48 male Wistar rats divided into groups: Naïve, EP, GIOP and GIOP + EP. Rats of GIOP and GIOP + EP groups received 7 mg/kg of dexamethasone intramuscularly once a week for 5 weeks. Following, EP and GIOP + EP groups were subjected to ligature-induced periodontitis. Naïve group experienced no manipulation. After 11 days, the animals were euthanized and left maxillae collected for macroscopic, radiographic, micro-tomographic and microscopic analysis of alveolar bone loss (ABL). Blood samples were collected for determination of bone-specific alkaline phosphatase (BALP) levels and the right femurs were removed for radiographic and biomechanical analysis.ResultsEP caused ABL and reduced BALP levels (p < 0,05), but it did not change the architecture or biomechanics of femur, compared to Naïve. GIOP did not cause ABL, but it significantly decreased alveolar bone mineral density (ABMD), bone percentage and trabecular thickness (Tb.Th) and increased alveolar bone porosity (p < 0.05) and significantly reduced BALP serum levels, as well as radiographic density and Young’s module of femur, compared to Naïve. There was a greater ABL in group GIOP + EP when compared to EP (p < 0.05). GIOP + EP caused a greater decrease on ABMD, Tb.Th, bone percentage and increased bone porosity (p < 0.05) and also presented a significant reduction in BALP levels (p < 0.05), in radiographic density and in Young’s module of femur compared to EP (p < 0.05).ConclusionsGIOP can potentiate the destructive effects of EP on alveolar bone and alter the systemic bone loss, by promoting bone resorption and reducing osteoblast activity.     

胰岛素治疗对糖尿病大鼠牙槽骨RANKL/OPG mRNA影响的研究

目的通过研究胰岛素治疗对糖尿病大鼠牙周组织病理改变及牙槽骨中NF-κB受体活化因子配体(Receptor activator of nuclear factor-κB ligand,RANKL)和骨保护素(osteoprotegerin,OPG)mRNA水平比值情况的影响,探讨糖尿病影响牙周病时牙槽骨吸收的机理。方法将12只大鼠采用静脉注射链脲佐菌素的方法建立糖尿病模型,并随机分为治疗组和对照组。治疗组给予胰岛素皮下注射,对照组注射等量生理盐水。分别于实验开始时、造模成功后和8周后处死时测量大鼠体重和血糖。右下磨牙区牙周组织脱钙后HE染色观察组织病变状况;应用RT-PCR检测左下磨牙区牙槽骨RANKL和OPG mRNA表达情况,并比较两组大鼠RANKL/OPG比值差异。结果胰岛素治疗组较糖尿病组牙周组织炎症反应减轻,牙槽骨吸收减弱;血糖值(P<0.05)及RANKL/OPGmRNA比值(P<0.01)降低。结论胰岛素治疗可能增加牙周组织修复和再生能力,降低糖尿病大鼠的牙槽骨RANKL/OPGmRNA比值。提示血糖水平增高可能是影响糖尿病大鼠的牙槽骨吸收危险因素之一。     

Longitudinal radiographical study on the rate of alveolar bone loss in patients of a dental school

Abstract Two sets of radiographs, taken at an interval of 4–14 years in 105 patients of a dental school, were examined in order to determine the rate of resorption of alveolar bone. The percentage loss of maximum alveolar bone height was measured in the interproximal and interradicular sites by means of the Schei ruler. The average percentage of interproximal bone resorption was 0.51 % (0.07 mm) per year. Age, sex, professional status, type of periodontal treatment and general state of health did not seem to affect the annual resorption rate. However, crowned teeth had a significantly greater rate of resorption than uncrowned teeth. Loss of bone tended to be more rapid in interdental as compared to interradicular areas. A positive and statistically significant correlation was found between initial resorption and annual tooth loss.     

Spontaneous alveolar bone loss after 4NQO exposure in Wistar rats

ObjectiveThis study evaluated the effect of an experimental carcinogenic, 4-Nitroquinoline 1-oxide (4NQO), in the spontaneous alveolar bone loss (ABL) in an animal model.DesignTwenty-two male Wistar rats were included in this study. They were randomly divided into two groups: the control group (n = 10) received food and water ad libitum, and the test group (n = 12) receive the same food; however, 25 ppm of 4NQO was diluted in the drinking water. All animals were euthanized after 20 weeks, and the tongues were removed and analyzed macroscopically to determine the presence of oral mucosal lesions. All specimens were paraffin-embedded and histological sections were obtained. The microscopic analysis was based on routine procedure (haematoxylin and eosin stain). The analysis of spontaneous ABL was performed by a calibrated examiner using standardized photographs and imaging software. Differences in spontaneous ABL were assessed among the three resulting groups: control, 4NQO with oral squamous cell carcinoma (OSCC), and 4NQO without OSCC.ResultsIn the 4NQO-treated group, nine animals developed OSCC. The animals in the 4NQO with OSCC group presented significantly more spontaneous ABL (0.65 ± 0.21 mm) than the control group (0.34 ± 0.05) (p < 0.001). The animals in the 4NQO without OSCC group showed a mean spontaneous ABL of 0.47 ± 0.13 mm, which was not statistically significant different when compared to the control group (p = 0.096).ConclusionsIt was concluded that the presence of OSCC enhanced spontaneous ABL in Wistar rats when compared to control animals. Additionally, it was shown that, solely, administration of 4NQO may not be considered responsible for alveolar bone destruction.