甲状旁腺激素对去卵巢大鼠骨质疏松牙周炎模型骨代谢的影响

目的：观察甲状旁腺激素对去卵巢大鼠骨质疏松牙周炎模型骨代谢的影响。方法：4月龄健康雌性Wistar大鼠68只,随机分成4组,每组17只。即A组（健康对照组）、B组（伪手术组）、C组（去势牙周炎组）,D组（去势牙周炎加甲状旁腺激素治疗组）。模型建立成功后,A、B、C组腹腔内注射等量的生理盐水,D组间歇性小剂量腹腔内注射等量甲状旁腺激素,隔日注射一次,用药8周。治疗后处死大鼠并通过CBCT扫描测定上颌骨密度,检测血清中钙（Ca2＋）、磷（P3＋）、碱性磷酸酶（ALP）水平。结果：治疗8周后,经CBCT图像测量,D组上颌骨密度较C组明显升高,差异有统计学意义（P〈O．05）,与A、B组上颌骨密度无明显差异,无统计学意义（P〉0．05）。D组外周血中ALP水平高于A、B、C组（P〈0．05）,差异有统计学意义,各组血清钙、磷值没有明显改变（P〉0．05）。结论．小剂量注射甲状旁腺激素能够增加骨密度并改善外周血中ALP的水平,促进牙槽骨的形成,对绝经期后牙周炎有明显的治疗作用。     

不同去势时间大鼠牙槽骨微结构变化的Micro-CT研究

目的： 观察不同去势时间大鼠牙槽骨微结构的改变,探讨去势时间对牙槽骨骨质疏松程度的影响。方法： 健康未孕雌性SD大鼠24只,随机分为去势组(OVX)与假手术组（sham）,每组各12只,分别在全麻下行双侧卵巢去势术与假手术。于术后3个月及6个月2个不同时间点分别处死每组大鼠各6只,取右侧上颌骨标本行Micro-CT扫描;观察去势3个月及6个月后大鼠上颌第一磨牙根分叉区牙槽骨微结构的改变。采用SPSS16.0软件包对数据进行统计学分析。结果： Micro-CT水平面、矢状面二维图像及三维重建均显示,去势3个月及6个月大鼠牙槽骨骨髓腔面积增加、骨小梁变细、部分发生断裂。骨结构参数分析显示,去势3个月及6个月后,大鼠牙槽骨骨密度（BMD）及骨体积分数（BV/TV）、骨小梁宽度（Tb.Th）均显著低于相应时间假手术大鼠（P<0.05）;去势6个月组较3个月组大鼠牙槽骨骨密度(BMD)、骨体积分数(BV/TV)、骨小梁宽度(Tb.Th)显著降低（P<0.05）。去势3个月及6个月大鼠骨小梁数目（Tb.N）及骨小梁分离度（Tb.Sp）显著高于相应假手术组（P<0.05）,且去势6个月组骨小梁数目(Tb.N)显著高于去势3个月组（P<0.05）。结论： 随着去势时间延长,大鼠牙槽骨骨量降低、骨小梁微结构破坏加剧,骨质疏松程度加重。     

雌孕激素缓释凝胶对去势牙周炎大鼠牙槽骨吸收部位修复再生作用的研究

目的:研究雌孕激素缓释凝胶对去势牙周炎大鼠牙槽骨修复再生的作用。方法:选取6月龄雌性大鼠,随机分为去势组和假手术组,去势术后12周检测血清钙、磷、碱性磷酸酶和E2浓度。用0.2 mm结扎线于单侧第一磨牙牙颈部结扎,结扎4周后,建立大鼠牙周炎模型,用Micro-CT观察骨丧失情况。移除结扎线,将大鼠分为假手术生理盐水组,假手术上药组,去势生理盐水组和去势上药组。将配制好的雌孕激素缓释凝胶和生理盐水分别注入大鼠牙周袋内,治疗8周后,进行Micro-CT分析和HE组织学染色。结果:去势大鼠骨密度降低,血清钙、磷浓度降低,碱性磷酸酶活性升高,E2浓度降低。牙周结扎后,假手术组牙槽骨有水平吸收,去势组牙槽骨不仅水平方向上的吸收,垂直方向上也同样有吸收,牙槽嵴高度降低明显,根分叉暴露。雌孕激素缓释凝胶联合应用后,牙槽骨骨密度(BMD)升高、骨小梁数量(Tb.n)增加、骨小梁分离度(Tb.Th)增加、骨小梁连接数(Tb.Pf)增多,破骨细胞减少,新骨形成。结论:雌孕激素缓释凝胶能够促进去势大鼠牙槽骨吸收部位的修复再生。     

甲状旁腺激素对大鼠绝经后骨质疏松牙周炎模型外周血中成纤维细胞生长因子23与碱性磷酸酶表达的影响

目的:通过动物实验,检测大鼠外周血中成纤维细胞生长因子23(FGF23)与碱性磷酸酶(ALP)水平的变化,探讨甲状旁腺激素(PTH)对其表达的影响及其在治疗牙周炎过程中的机理。方法:选用68只3月龄雌性Wistar大鼠随机分为健康对照组(A组),伪手术对照组(B组),去势牙周炎组(C组),去势牙周炎并甲状旁腺激素注射组(D组)。C组和D组去势牙周炎模型建立成功后,D组间歇性低量腹腔内注射甲状旁腺激素,A、B和C组腹腔内注射等体积的生理盐水。两个月后,麻醉下方块截取包括实验区磨牙的双侧上颌骨,HE染色后进行观察。收集实验各阶段外周血,检测FGF23、ALP水平。结果:注射PTH后,D组外周血FGF23、ALP水平高于A、B、C组(P<0.05),D组牙槽骨中骨小梁较C组粗大、致密,排列有规则,与A、B组相似。结论:甲状旁腺激素可升高外周血FGF23、ALP的水平,有利于成骨,对绝经期后牙周炎有治疗作用。     

葛根素影响去势雌性大鼠牙周炎症的实验研究

目的探讨葛根素对去势SD大鼠牙周炎形成和发展的影响。方法雌性3月龄SD鼠60只分为6组,A组（正常对照组）、B组（牙周结扎组）、C组（去势组）、D组（去势结扎组）、E组（去势葛根素组）、F组（去势结扎葛根素组）各10只。C、D、E、F组大鼠分别经腹部切口摘除双侧卵巢;B组作假手术。B、D、F组在大鼠右侧上颌第一磨牙牙颈部结扎1根0.2 mm不锈钢丝。E、F组大鼠术后1周开始每天腹腔注射100 mg/kg葛根素;B、C、D组大鼠每天腹腔注射相应剂量生理盐水。给药12周后分别观察各组大鼠牙槽骨吸收值、血钙值、血磷值、血清碱性磷酸酶含量以及牙槽骨组织病理学改变。结果所有牙周结扎组都表现出不同程度的局部牙周炎症;各去势组大鼠都存在不同程度的骨质疏松改变,注射葛根素组病理学表现较未注射葛根素组为轻。血清钙水平去势各组与正常对照组差异均有统计学意义（P〈0.05）;血清碱性磷酸酶水平去势各组与正常对照组差异有统计学意义（P〈0.05）;血清磷水平在各组间差异无统计学意义（（F=1.764 1,P〉0.05）。A、C、E组未观察到明显的牙周骨质吸收,B、D、F组牙槽骨吸收值分别为（0.21±0.08）mm、（0.55±0.07）mm、（0.42±0.10）mm,3组两两比较,差异均有统计学意义（P〈0.01）。结论在局部刺激因素存在的前提下,雌激素水平降低可增加大鼠对牙周炎症的易感性和反应程度;葛根素对伴随雌激素降低的牙周炎的发生发展有一定的阻缓作用。     

不同去势时间对大鼠牙槽骨微结构影响的比较研究

目的 比较不同去势时间对大鼠牙槽骨微结构的影响,探讨牙槽骨骨质疏松大鼠模型建立成功的参数。方法 24只6月龄雌性SD大鼠,随机分为4组：（1）对照组1（Sham1）;（2）去势组1（OVX1）;（3）对照组2（Sham2）;（4）去势组2（OVX2）。分别在全麻下行假手术和双侧卵巢去势术。于术后3个月和4个月处死各组大鼠,取双侧上颌骨标本,通过Micro-CT扫描、HE染色、抗酒石酸酸性磷酸酶（TRAP）染色、Van Gieson染色、荧光双标观察并分析牙槽骨微结构的变化。结果 去势3个月后OVX1组与Sham1组大鼠相比,体重增加25.09%（P<0.01）;牙槽骨骨体积分数（BV/TV）、骨小梁数目（Tb.N）、骨小梁分离度（Tb.Sp）,牙骨质界-牙槽嵴顶（CEJ-ABC）距离无改变（P>0.05）,骨小梁宽度（Tb.Th）降低了12.44%（P<0.05）,破骨细胞数量增加了40.12%（P<0.01）;骨形成沉积率（MAR）无明显改变（P>0.05）;去势4个月后OVX1组与Sham1组大鼠相比,体重进一步增加了26.25%（P<0.01）,BV/TV、Tb.Th、MAR分别降低了11.15%、17.22%和38.45%（P<0.01）,Tb.Sp和破骨细胞数量分别增加了81.89%和35.67%（P<0.01）,Tb.N和CEJ-ABC距离无变化（P>0.05）,HE和Van Gieson染色均表明OVX2组大鼠牙槽骨骨量降低,骨髓腔面积增加,骨小梁微结构破坏、变细,部分区域发生断裂。结论 6月龄雌性SD大鼠去势4个月后,牙槽骨发生明显骨质疏松,可作为合适的牙槽骨骨质疏松大鼠模型参数的理论依据。     

丹参素防治去卵巢大鼠牙槽骨骨量的丢失

目的:探讨丹参素对大鼠牙槽骨骨量的影响、丹参素与雌激素防止牙槽骨骨丢失的疗效比较以及丹参素与雌激素是否具有防止牙槽骨骨丢失的协同效应.方法:40只SD大鼠随机分为5组:假手术组(Sham)、去卵巢组(OVX)、雌激素组(E2)、丹参素(Tan)及丹参素与雌激素联合用药组(E2 Tan).雌激素组、丹参素组和丹参素与雌激素联合用药组分别用雌激素100 μg·kg-1·d-1、丹参素12.5 mg·kg-1·d-1和丹参素12.5 mg·kg-1·d-1加雌激素50 μg·kg-1·d-1给大鼠灌胃,17欠/d,共90 d.实验90 d后取大鼠的牙槽骨,脱钙,切片,染色,用骨形态计量学方法测量牙槽骨松质骨的骨量,计算牙槽骨的骨静态参数.结果:与假手术组相比,去卵巢组牙槽骨骨小梁面积百分数减小(P＜0.01)和骨小梁分离度增大(P＜0.05).与去卵巢组相比,雌激素组牙槽骨骨小梁面积百分数、骨小梁厚度均增大(P＜0.01),丹参素组及联合用药组牙槽骨骨小梁面积百分数增大(P＜0.05).与丹参素组相比,雌激素治疗组及联合用药组各项测量指标差别均没有统计学意义.结论:丹参素都能防治牙槽骨骨质疏松且疗效与雌激素相当,但丹参素与雌激素在防治牙槽骨骨质疏松时没有协同作用.     

雌性激素对牙槽骨骨量的影响

本实验采取切除大鼠双侧卵巢制造人工绝经模型,观察雌激素缺乏对股骨与牙槽骨骨质疏松产生的影响。采用骨密度测定,骨小梁参数测定,包括骨小梁体密度(TBV),骨小梁板厚度(MTPT)和平均骨小梁板间隙(MTPS),同时检测骨Ca、Mg含量,血清Ca、Me、P、ALP及空腹尿Ca/cr值。结果表明,雌激素水平低下与股骨、牙槽骨骨密度降低有正相关性,骨小梁参数亦表现相应的改变。给予去势动物雌激素治疗后骨密度有所增加。以上结果并得到组织学证实,说明雌激素缺乏是引起牙槽骨骨质疏松的原因之一。     

雌激素缺乏对大鼠核因子C（Nfic）与成骨相关基因表达的影响

目的：通过检测分析骨质疏松大鼠股骨组织核因子C(Nuclear Factor I-c,Nfic)与成骨相关基因表达情况,探讨雌激素缺乏状况下两类基因表达的相关性,探寻雌激素相关的骨质疏松发生原理。方法：3月龄未交配雌性SD大鼠20只,随机分为两组： A、假去势手术组(SHAM); B、去势手术组(OVX)。对A组大鼠行假去势手术,B组大鼠行去势手术。去势手术前、去势手术后1、2、3、4、5、6周及处死前称重,观察大鼠体重变化。卵巢切除术后1.5个月,采用双能骨密度测量仪测量大鼠腰椎及股骨远中骨密度,处死后,取双侧后肢股骨进行Q-PCR,检测核因子C(Nfic)、核心结合因子2(Runx2)、碱性磷酸酶(Alp)的mRNA表达情况。结果：去势手术前,两组大鼠体重差异无统计学意义(P>0.05);术后2、4、6周, OVX组大鼠体重较SHAM组显著增加(P<0.05, P<0.01, P<0.01)。术前,两组大鼠腰椎及左股骨骨密度差异无统计学意义(P>0.05);术后1.5个月, OVX组大鼠腰椎及左股骨骨密度较SHAM组显著降低(P<0.01, P<0.05)。去势组大鼠的Nfic、 Runx2、 Alp基因表达量明显低于假去势手术组(P<0.05)。结论：雌激素缺乏大鼠较正常组肥胖,骨密度减低,骨质改变,成骨能力减弱,成脂功能提高; Nfic基因与Runx2、 Alp成骨相关基因表达量呈正相关。     

乳铁蛋白下调脂多糖激发的人牙周膜细胞Toll样受体4表达的研究

目的 观察乳铁蛋白（LF）对经脂多糖（LPS）刺激的人牙周膜细胞（hPDLCs）表达Toll样受体4（TLR4）的影响。方法 采用组织块酶消化法培养hPDLCs,鉴定后取第4代细胞,分成空白对照组、LPS组、LPS+LF组。空白对照组不加任何刺激,LPS组加入0.1 μg?mL-1 LPS;LPS+LF组在加入0.1 μg?mL-1 LPS 2 h后,加入10 μg?mL-1 LF。以加入LF时开始计算时间,4 h后采用实时定量聚合酶链反应（RT-PCR）法检测hPDLCs中TLR4 mRNA的表达,24 h后采用细胞免疫荧光染色法观察TLR4蛋白的表达。结果 RT-PCR检测显示：LPS+LF组TLR4 mRNA表达较LPS组明显降低（P<0.05）,与空白对照组无明显差异（P>0.05）。细胞免疫荧光染色法显示：LPS+LF组TLR4蛋白的表达强度较LPS组减弱（P<0.05）,与空白对照组无明显差别（P>0.05）。结论 LF可以下调LPS激发的hPDLCs中TLR4的表达,在牙周炎症TLR4信号通路的调控过程中有一定的作用。     

2种给药方式下辛伐他汀对牙周炎骨质疏松大鼠上颌骨骨丢失的影响

目的比较辛伐他汀(Simvastatin,SIM)在不同给药方式下抑制牙周炎骨质疏松大鼠上颌骨骨丢失的作用效果。方法 24只4月龄雌性SD(Sprague Dawley)大鼠,随机分成4组:假手术组(SHAM),去势+绑线组(OVX+LIG),去势+绑线+辛伐他汀灌胃给药组(OVX+LIG+Oral SIM),去势+绑线+辛伐他汀局部用药组(OVX+LIG+Local SIM)。适应性喂养1周后,进行骨质疏松造模手术——双侧卵巢切除术(OVX),4周后,进行牙周炎造模手术——分别于双侧上颌骨第一、第二磨牙进行8字结扎绑线术(LIG),4周后拆除绑线,用药组开始辛伐他汀给药。8周后处死所有大鼠,收集双侧上颌骨和血清,分别进行进一步检测。检测包括micro-CT扫描,硬组织切片观察、染色,酶联免疫吸附实验(ELISA)。结果相比于对照OVX+LIG组,OVX+LIG+Local SIM组可见明显釉牙骨质界-牙槽嵴顶(CEJ-ABC)距离的减少(P<0.05),OVX+LIG+Oral SIM组与OVX+LIG+Local SIM组可见明显牙槽骨的骨密度(BMD)和骨体积分数(BVF)升高,OVX+LIG+Oral SIM组可见明显骨钙素(OC)上升,抗酒石酸酸性磷酸酶5b(TRAP5b)下降。结论局部或全身系统应用辛伐他汀能减缓牙周炎伴骨质疏松大鼠上颌骨的骨丢失,其中局部注射辛伐他汀对牙槽嵴顶骨形成具有促进作用。     

去势法大鼠骨质疏松症模型建立的探讨

目的 探讨去势法建立大鼠骨质疏松症模型的可行性。方法 将30只老年Wistar雌性大鼠随机分成手术组(OVX)和假手术组(SHAM),手术组切除双侧卵巢。两组于术前、术后3个月行股骨X线检查,测定大鼠血清碱性磷酸酶水平;术后3个月处死大鼠,取其右侧股骨拍摄X线片,并制作脱钙切片行苏木精-伊红(HE)染色,行骨组织形态学分析。结果 去势3个月后,X线片显示OVX组股骨骨密度明显低于SHAM组,表现为骨皮质密度降低,透光性增加明显;血清中ALP水平,OVX组术后水平明显高于术前,高于SHAM组;股骨横断面HE染色结果 显示OVX组骨小梁结构疏松或断裂,骨髓腔扩大,骨质流失较多,但骨皮质厚度无明显下降。结论 去势法建立大鼠骨质疏松症模型切实可行,造模3个月。大鼠股骨骨密度下降,骨质丢失增加,骨小梁形成减少,骨质疏松形成。     

雌激素对骨质疏松时种植体骨愈合的影响:Ⅱ骨计量学和电镜观察

目的 :研究雌激素替代治疗对骨质疏松时种植体骨愈合的影响。方法 :选用32周龄雌性SD大鼠36只 ,并随机分为假手术组、卵巢切除组及雌激素组。卵巢切除12周后于大鼠胫骨近中干骺端植入纯钛螺纹状种植体 ,雌激素组同时肌注苯甲酸雌二醇。种植术后4周及12周分两批处死大鼠 ,摘取胫骨 ;标本分别进行扫描电镜观察和骨计量学测量。结果 :在种植后4周及12周时 ,雌激素组除12周时皮质骨结合率与卵巢切除组无显著差异外 ,其它各项骨计量学参数均显著高于卵巢切除组 (P<0.05或P<0.01) ;而与假手术组比较 ,除骨矿化速度及4周时单位骨量外 ,其他各项指标均无显著差异 (P>0.05)。电镜观察种植体—骨界面愈合雌激素组和假手术组均优于卵巢切除组。结论 :雌激素替代治疗可促进实验性骨质疏松大鼠种植体骨愈合 ;该方法有助于增加临床绝经性骨质疏松患者牙种植体骨整合率     

Radiographic assessment of bone density around integrated titanium implants after ovariectomy in rats

OBJECTIVES: This study evaluated the influence of ovariectomy 8 weeks after implant placement on bone integrated to titanium implants. MATERIAL AND METHODS: Thirty-eight female rats were submitted to a titanium implant at the tibiae proximal methaphysis. After a healing period of 8 weeks the animals were randomly divided into three groups: control (CTL-10 animals), sham-operated (SHAM-14 animals) and ovariectomy (OVX-14 animals). The CTL group was then sacrificed in order to confirm integration of the implant. The SHAM group was submitted to fictitious surgery and the OVX group was submitted to bilateral ovariectomy. After 12 weeks post-implant placement, the SHAM and OVX groups were sacrificed. In order to confirm the systemic osteopenia in rats, a dual-energy X-ray absorptiometry (DXA) was performed. For the evaluation of bone density, digital radiographs were taken. The grey level of the bone adjacent to implant was measured using image software and the bone density was calculated at six points on both sides of the implant. RESULTS: Densitometry measurements of the femur confirmed systemic bone mass loss in the OVX group. Individualized bone analyses of different regions surrounding the implant showed a significantly lower radiographic bone density (P < 0.05) in the cancellous region of the OVX group (77.48 +/- 23.39 grey levels) when compared with the CTL and SHAM groups (91.61 +/- 32.10 and 102.57 +/- 32.50 grey levels, respectively). CONCLUSIONS: The present study showed a decrease of the radiographic bone density in the cancellous region of bone around titanium implants placed 8 weeks before ovariectomy in rats.     

Influence of different durations of estrogen deficiency on alveolar bone loss in rats

The purpose of this study was to morphometrically evaluate the influence of different durations of ovariectomy-induced estrogen deficiency on alveolar bone loss associated with ligature-induced bone loss in rats. Sixty female Wistar rats were randomly assigned to ovariectomy (OVX test group) or sham operation (SHAM control group). The OVX and SHAM groups were each distributed into three subgroups of ten rats each according to the duration of estrogen deficiency (30, 60 and 90 postoperative days). In all groups, for the last 30 days of the experimental period, cotton ligatures were placed around the cervix of the right upper second molar; the contralateral tooth was left unligated to serve as a control. The maxillary bones were removed, and the alveolar bone loss was analyzed by measuring the distance between the cementoenamel junction and the alveolar bone crest at the buccal site of the right upper second molar. A comparison between the ligated and unligated groups verified the presence of ligature-induced alveolar bone loss (p < 0.05). No significant differences were observed among the unligated groups (p > 0.05). A significant increase in bone loss was observed when ligation occurred 90 days after ovariectomy compared with the sham group (p < 0.05). These results demonstrate that long-term estrogen deficiency affects ligature-induced alveolar bone loss.     

The influence of loss of bone mass on induced periodontal disease: a radiographic and densitometric study of female rats

BACKGROUND: Changes in mineral density in the mandibular and femoral bones (BMD) after estrogen deficiency caused by ovariectomy (OVX) and the influence of these changes on induced periodontal disease were evaluated in female rats. METHODS: Forty-eight female Holtzman rats (90 days old) were randomly divided into five groups: 0: control (N = 9); 1: SHAM without induced periodontal disease (N = 11); 2: SHAM with induced disease (N = 10); 3: OVX without induced disease (N = 9); and 4: OVX with induced disease (N = 9). In groups 2 and 4, the first lower molars were tied with ligatures for 30 days 120 days after surgery. After 5 months the animals were sacrificed to measure global mineral density (BMD) and that of the sub-regions of the mandible and femur by dual energy x-ray absorptiometry (DXA). The extent of vertical bone loss was evaluated with digital radiography by measuring the distance from the bone crest to the cemento-enamel junction at the mesial of the first lower molar. RESULTS: Results of the femur (Kruskal-Wallis test) showed a significant difference (P <0.001) between the groups SHAM and OVX in bone density values for all regions. Comparison between the groups in relation to the BMD of the mandible, both in the sub-regions and global revealed no differences (P >0.05). The vertical bone loss measured for the groups with induced disease was similar (P = 0.713). CONCLUSIONS: Differences between the groups were found in the bone mineral density BMD of the femur but not of the mandible. OVX had no influence on induced periodontal disease.     

Effect of ovariectomy on bone remodeling adjacent to hydroxyapatite-coated implants in the tibia of mature rats.

PURPOSE: The purpose of this study was to examine the effects of estrogen deficiency on bone remodeling adjacent to implants in the tibia of mature rats. MATERIALS AND METHODS: Hydroxyapatite-coated implants were placed bilaterally in the proximal metaphysis of the tibia of 18 female Wistar rats (48 weeks old), and ovariectomy was performed 168 days later. As a control, sham ovariectomy was performed in a similar group of 18 rats. Six animals from each group were killed at 28, 84, and 168 days after ovariectomy. Undecalcified sections were prepared, and changes in the bone tissue around the implants were evaluated histologically. Histomorphometric measurements were made with a computer-based image analyzer to quantify the unit bone mass around each implant and the amount of implant-bone contact. RESULTS: In the cortical bone area, ovariectomy induced only a slight decrease in bone contact with the implant, compared with that in the sham-operated rats. However, both the bone volume around the implant and implant-bone contact were significantly decreased in the cancellous bone area in ovariectomized rats compared with the sham-operated rats. CONCLUSION: Thinning of the bone trabeculae holding dental implants may occur with estrogen deficiency.