胰岛素样生长因子I对高糖条件下成骨细胞骨形成的影响

目的:研究胰岛素样生长因子I对高糖条件下成骨细胞骨形成的影响,探讨胰岛素样生长因子I对糖尿病性骨病的作用机制.方法:离体实验通过对细胞增殖和矿化的检测,从细胞分子水平评价胰岛素样生长因子I对高糖环境下成骨细胞的作用.体内实验诱导1型糖尿病大鼠动物模型,分别给予胰岛素(6～8 U/d)和胰岛素样生长因子I(30 μg/kg·d)治疗,通过X线、组织切片HE染色和四环素双标记的方法观察牙槽骨改建情况.结果:离体实验的结果显示胰岛素样生长因子I可减少高浓度葡萄糖引起的成骨细胞的异常增殖,促进钙沉积和矿化结节的形成.体内实验研究显示与正常组相比,糖尿病大鼠拔牙创骨愈合减慢,骨形成减少,牙槽骨高度和牙槽骨骨形成率显著降低.胰岛素样生长因子I的治疗不仅能控制糖尿病大鼠的血糖保持在正常范围内,还可以增加牙槽骨高度和提高骨形成率.结论:高浓度葡萄糖导致糖尿病大鼠拔牙后骨形成减少、牙槽骨高度降低等病理改变;胰岛素样生长因子I可以促进糖尿病状态下成骨细胞骨形成和矿化,有利于糖尿病大鼠拔牙后骨创愈合和新骨形成.     

邻牙向拔牙区移动最佳时机选择的实验研究

目的　研究拔牙创愈合的生理过程和牙齿向拔牙区移动的生物学反应,探讨邻牙向拔牙区移动的最佳时机。方法　30只同源雄性SD大鼠分为5组,拔除上颌第一磨牙,在拔牙后不同的时间制作口内矫治器,牵第二磨牙向拔牙区移动。所有的大鼠分别在矫治器加力前两天和处死前两天给予四环素和钙黄绿素腹腔注射;制备硬组织切片,采用骨硬组织形态测量和计算机图像处理技术,对向处于不同愈合阶段的拔牙区移动牙齿时的骨改建参数进行定量分析。结果　①骨改建同时包括吸收和形成两个过程;②近中牙槽骨面(压力侧)骨吸收较远中 (张力侧)活跃,而远中牙槽骨面(张力侧)骨形成则较近中(压力侧)活跃;③骨形成参数、骨吸收参数均在拔牙后1 周存在一个峰值。结论　①拔牙后宜早期移动牙齿,以便充分利用拔牙创的骨改建优势;②其理想的移动时机为拔牙后1周左右。     

碱性成纤维细胞生长因子对拔牙后牙槽骨骨密度的影响

研究碱性成纤维细胞生长因子（bFGF）对拔牙后牙槽骨愈合的影响。方法：采用随机双盲对照临床研究,双能X线吸收法测量实验组、对照组拔牙后即时、1、2、3和6月时牙槽骨骨密度的变化。结果：应用bFGF的实验组牙槽骨骨密度在1、2和3月时均明显高于对照组（P＜0．01或0．05）拔牙后即时和6月时牙槽骨骨密度两组无显著差异。结论:拔牙后局部应用成纤维细胞生长因子有良好的促进拔牙创骨愈合的作用。     

不同的拔牙创处理技术在拔牙后牙槽突骨量保存中的作用

目的：通过动物实验探讨不同的拔牙创处理方法在预防拔牙后牙槽骨吸收中的作用。方法：6条杂种犬分别拔除两侧下颌第一第二双尖牙,测量缺牙处牙槽骨的高度和宽度。随机在一拔牙窝中置入Bi o-Oss骨粉,另一拔牙窝血凝块形成自然愈合。两侧创口分别覆盖胶原膜和颊侧牙龈翻瓣后拉拢缝合。三个月后取材测量缺牙区牙槽骨的高度和宽度。结果：置骨粉组无论覆盖胶原膜还是翻瓣后牙龈拉拢缝合的牙槽骨高度和宽度的丧失均比自然愈合组小。而覆盖胶原膜组和牙龈拉拢缝合组相比骨量变化没有统计学差异。结论：置入Bi o-Oss骨粉可以有效预防拔牙后牙槽骨的吸收,拔牙创口的不同处理方法对牙槽骨吸收无明显影响。     

种植相关的牙槽嵴保存技术

充足的牙槽骨宽高度和骨质量是种植体植入的前提条件。但拔牙后局部牙槽骨的改建和吸收极易造成骨量和骨质减少,影响种植体植入。牙槽嵴保存技术有利于拔牙后牙槽骨的愈合,减少骨吸收,为后期种植修复创造条件。本文将对近年来牙槽嵴保存的方法、疗效及后期种植体植入效果做一综述。     

成骨诱导剂对拔牙创愈合的影响

目的 探讨以明胶海绵为载体,地塞米松、维生素C和β-甘油磷酸钠组成的成骨诱导剂对拔牙创愈合和牙槽嵴形态改建的影响。方法选用50只家兔,拔除双侧上颌第一前磨牙,右侧拔牙创内填入载有成骨诱导剂的明胶海绵,作为实验侧;左侧填入空载明胶海绵,作为对照侧。拔牙后第1、2、4、8、12周各处死10只动物,取双侧牙槽骨标本,拍摄X线片,并测量骨缺损区新骨密度;用组织学方法评价拔牙创愈合情况;并于12周时,测量拔牙区牙槽嵴高度吸收值。结果X线片骨密度测量显示：术后2、4、8、12周,实验侧骨密度值均高于对照侧,差异有统计学意义（P<0.01）。组织学检查显示：实验侧拔牙创内成骨现象较对照侧早,成骨细胞分化和增殖更活跃。
12周时实验侧牙槽嵴高度吸收值小于对照侧,差异有统计学意义（P<0.01）。结论 由地塞米松、β-甘油磷酸钠和维生素C组成的成骨诱导剂能促进拔牙创愈合,加速成骨和骨改建。     

骨形成蛋白复合骨拔牙创种植的实验研究

本实验用骨形成蛋白（BMP）复合陶瓷化牛骨（CeramicBovineBone，CBB）种植于狗的拔牙创内，通过大体观察、组织学切片及X线显微分析等方法，对比观察了BMP复合骨和单纯陶瓷化骨在拔牙创愈合过程中的作用。实验结果表明BMP复合骨的骨诱导性、成骨效率及骨成熟程度明显优于单纯陶瓷化骨，起到了促进拔牙创愈合，防止牙槽骨吸收萎缩的作用。     

胰岛素样生长因子-I对培养人牙周膜成纤维细胞生物学活性的影响

胰岛素样生长因子(IGF)可通过直接作用于成骨细胞或通过甲状旁腺素间接影响骨代谢过程而参与骨的改建。本文利用细胞培养技术观察了IGF-I对培养人牙周膜成纤维细胞(PDLFs)增殖、碱性磷酸酶(ALP)活性变化以及蛋白质含量改变的影响。结果显示,IGP-I对PDLFs有明显的促增殖作用,对PDLFs的ALP活性、蛋白质合成也具有较强的促进作用,表明IGF-I可能通过PDLFs发挥其调节牙槽骨改建的作用,从而在牙齿移动过程中起重要作用。     

唑来膦酸对大鼠颌面骨和外周骨创伤后骨改建的影响

目的 研究唑来膦酸对大鼠颌面骨和外周骨创伤后骨改建的影响。方法 SD大鼠随机分为实验组和对照组,每周分别给予尾静脉注射唑来膦酸(80μg/kg)和PBS。用药两周后,在全麻下拔除一侧上颌第一磨牙,并在同侧胫骨近心端制备骨缺损,缝合创口,继续用药至术后1、4和12周后分批处死,分离并收集骨组织样本。Micro-CT分析各组骨缺损区新骨形成情况。HE和Masson染色分析骨缺损区软组织愈合情况、新骨形成情况、有无炎症反应和死骨形成等。ELISA法检测骨改建过程中关键因子RANKL和OPG的表达。结果 Micro-CT结果显示,实验组拔牙创表面高低不平,中部浅凹处可见游离的死骨片,而对照组拔牙创新骨形成区域与周边骨质均匀连续,进行了正常的生理性骨改建。实验组胫骨缺损区愈合,骨皮质完整连续,较对照组厚且致密,骨松质内的新生骨亦明显较对照组排列紧密。术后4周和12周,实验组胫骨BV/TV值较对照组明显上升(P<0.05),实验组颌骨BV/TV值较对照组差异无统计学意义。组织学染色显示,实验组颌骨拔牙创黏膜未愈合或延迟愈合,未愈合的黏膜下方可见暴露骨坏死,骨质出现不同程度的硬化,且周围伴有大...     

动情周期不同阶段正畸牙移动影响牙周组织胰岛素样生长因子表达的研究

目的探讨正畸力对牙周组织胰岛素样生长因子（IGF）表达的影响,从体内实验角度阐明雌激素和应力对局部骨改建的调控途径和机制。方法建立在Wistar雌性大鼠动情周期不同阶段给予正畸加力的实验模型,采用核酸原位杂交技术检测雌性大鼠动情周期不同阶段牙周组织中IGF mRNA的表达变化。采用SPSS 11.0软件包,单因素方差分析法（one way ANOVA）比较动情周期同一阶段加力实验组与对照组差异,Student- Newman- Keuls（S- N- K）法进行同一组内动情周期不同阶段各亚组间的两两比较。结果正畸牙移动使处于动情周期不同阶段的雌性大鼠牙周组织中的IGF mRNA含量增加,其中IGF- Ⅰ mRNA的表达在动情期最低,而动情前期最高（P<0.05）;而IGF- ⅡmRNA的表达在动情周期中没有明显规律。结论IGF- Ⅰ不仅可以在应力反应中由骨形成细胞在局部合成,而且还与动情周期的全身激素状态有关,而IGF- Ⅱ则是对应力发生反应的一种局部生长因子。     

Effects of insulin‐like growth factor I on alveolar bone remodeling in diabetic rats

Fang Y, Wang L‐P, Du F‐L, Liu W‐J, Ren G‐L. Effects of insulin‐like growth factor I on alveolar bone remodeling in diabetic rats. J Periodont Res 2013; 48: 144–150. © 2012 John Wiley & Sons A/S Background and Objective: Diabetes is a chronic hyperglycemic disorder and results in a tendency to develop osteoporosis. Furthermore, the delayed healing of tooth‐extraction wounds, the activation of alveolar resorption and the suppressed formation of bone around implants are difficult for dentists to resolve. In diabetes, insulin‐like growth factor I (IGF‐I) appears to enhance the differentiation of osteoblasts and to activate the mineralization of bone. Hence, the aim of this study was to investigate the effects of insulin‐like growth factor I on the remodeling of alveolar bone in diabetic rats. Material and Methods: Diabetes was induced in 40 male Sprague‐Dawley rats by intravenous administration of alloxan. The teeth of the rats were extracted to investigate remodeling of alveolar bone. Insulin‐like growth factor I was administered, via intraperitoneal injection, to diabetic rats following tooth extraction. The remodeling of alveolar bone was determined using radiographic data, histological analyses and tetracycline fluorescence labeling. Results: Compared with the control group, diabetes decreased alveolar bone formation. The height of alveolar bone and the bone‐formation rate was significantly lower in the untreated diabetic group than in the control group or in the treated rats. Treatment with insulin‐like growth factor I not only regulated abnormal blood glucose levels but also increased the height of the alveolar bone and increased the bone‐formation rate relative to the results in diabetic animals. Furthermore, the expression of glucose transporter‐1, the main transporter of glucose, was changed by hyperglycemia. Conclusion: The results suggest that insulin‐like growth factor I treatment increases the volume of newly formed bone following tooth extraction and normalizes the expression of glucose transporter‐1 in diabetic rats, which may play an important role in bone formation and mineralization.     

The effect of simvastatin on remodelling of the alveolar bone following tooth extraction

Suppression of residual ridge resorption after tooth extraction is a hot spot in dental research. Recently, simvastatin was reported to influence bone turnover by stimulating bone formation. In this study, the effect of simvastatin application on residual ridge resorption following tooth extraction was investigated. Sixty male Wistar rats were randomly divided into experimental and control groups (n=30). Polylactic acid/polyglycolic acid copolymer carriers, with or without simvastatin, were implanted into extraction sockets of right mandibular incisors. The rats were killed at 1, 2, 4, 8 or 12 weeks after implantation. The relative height of the residual alveolar ridge was significantly greater in the experimental compared to the control group at 2, 4, 8 and 12 weeks. The bone mineral density in the experimental group was significantly higher than that in the control group at 4, 8 and 12 weeks. A larger newly formed bone island was observed in the experimental group at 4 weeks, and higher bone formation rate and quality were found than in the control group at different time points except 1 week. The findings indicate that local application of simvastatin would effectively preserve the residual alveolar bone by promoting bone formation in the extraction socket.     

引导再生术用于下颌第三磨牙拔除后牙槽骨再生的疗效评估

目的观察联合应用Bio-oss骨代材料和Bio-gide胶原膜的引导骨再生术(guided bone regeneration,GBR)治疗下颌阻生第三磨牙拔除后邻牙远中牙槽骨缺损的疗效。方法将24例下颌阻生第三磨牙拔除患者随机分为GBR组和对照组,GBR组12例,对照组12例。GBR组拔牙后行Bio-oss、Bio-gide引导骨再生术。对照组拔牙后常规处理拔牙创。分别记录术前、术后3个月拔牙区域牙槽骨再生情况,邻牙远中牙周探诊深度(probing depth,PD)、牙槽嵴顶到釉牙骨质界的距离、松动度及敏感度。结果与术前相比两组术后拔牙区域均存在牙槽骨再生,X线片显示,GBR组疗效优于对照组,且有显著性差异。GBR组新骨形成量较多,牙周探诊深度减小,邻牙远中牙槽嵴顶到釉牙骨质界的距离减小。无邻牙松动和敏感病例,对照组新骨形成量较少,牙周探诊深度和邻牙远中牙槽嵴顶到釉牙骨质界的距离变化不明显,存在部分邻牙松动和敏感病例。结论联合应用Bio-oss骨代材料和Bio-gide胶原膜行引导骨再生术可促进拔牙区域牙槽骨再生和邻牙远中牙槽骨高度的改善。     

炎症对大鼠牙槽骨骨重建的影响

目的：了解拔牙窝残存炎性组织对拔牙后骨重建过程的影响。方法：健康成年SD大鼠56只,6只用于牙齿折裂炎症感染模型建立的预实验,X线片及病理确定8周为根周存在囊肿或肉芽肿炎症感染的时间点。50只大鼠建立下颌左右第一磨牙根周感染模型,8周后根据X线根尖片取36只根尖部炎症明显的大鼠,根据自身对照原则,左侧实验组牙齿拔除后不刮治,右侧对照组刮除感染组织。术后4周、8周、12周分别进行游标卡尺测量、X线影像学检查和组织学检查,评价拔牙后左右侧牙槽骨骨重建是否有差异。结果：术后4周、8周、12周两组牙槽嵴颊舌侧高度差存在差异,实验组颊舌侧高度差值较大,术后4周、8周实验组新骨形成明显少于对照组。结论：炎症组织使拔牙后颊侧牙槽嵴高度明显下降,拔牙窝的前期修复速度减慢。     

新型硅磷酸钙用于大鼠拔牙位点保存的早期成骨性能研究

目的    通过SD大鼠拔牙窝模型研究硅磷酸钙（CPS）骨粉的体内成骨性能。方法    选择45只6周龄SD大鼠,全麻下拔除右侧上颌2颗磨牙后按照拔牙窝充填材料随机分为3组,每组15只。CPS组：拔牙后于拔牙窝内放入CPS骨粉,用Bio-Gide膜覆盖拔牙窝并缝合;Bio-Oss组：拔牙后于拔牙窝内放入Bio-Oss骨粉,用Bio-Gide膜覆盖拔牙窝并缝合;对照组：拔牙后不放置充填材料,直接用Bio-Gide膜覆盖拔牙窝并缝合。于术后2、4、8周分别处死每组大鼠5只并取材上颌骨,采用影像学和组织学检测方法测量并评价拔牙窝牙槽骨愈合情况。结果  所有大鼠样本在术后2、4、8周这3个时间点的拔牙位点骨体积分数、骨密度及骨小梁厚度均随着术后时间延长而增大。术后4周时,Bio-Oss组拔牙位点骨体积分数、骨小梁厚度大于CPS组和对照组（P < 0.05）。术后8周时,CPS组的拔牙位点骨体积分数、牙槽骨宽度、牙槽骨高度及骨密度略高于Bio-Oss组和对照组, CPS组的骨小梁厚度介于Bio-Oss组和对照组之间,但3组间各指标的差异均无统计学意义（均P > 0.05）。组织学观察发现,术后8周CPS组和Bio-Oss组仅可见少量的未降解材料,周围有较多新骨形成,骨质较致密。结论    CPS在体内具有良好的促成骨能力和降解性能,可有效减少拔牙后牙槽骨萎缩,具有作为位点保存充填材料的潜力。     

Effect of streptozotocin-induced diabetes mellitus on alveolar bone deposition in the rat

Effects of diabetes on alveolar bone remodelling were assessed by quantitative histology and a chronological lead-labelling technique. Experimental diabetes was induced by a single dose of 40 mg/kg of streptozotocin. Remodelling of the alveolar wall surrounding the root of mandibular first molar was studied in control rats fed ad libitum, and in diabetic and insulin-treated diabetic rats 24 days after the induction of diabetes. The volumes of bone formation on the mesial side of the alveolar wall were evaluated over a 10-day period by chronological lead-labelling and computer image analysis. For a histometric measure of bone-resorption, the number of osteoclasts along the distal surface of the alveolar wall was counted. The volume of bone formed and the number of osteoclasts were significantly lower in the diabetic rats than in the controls, but insulin treatment of diabetic rats normalised these histomorphometric measures of bone turnover. These results demonstrate that streptozotocin-induced diabetes mellitus reduces the rate of bone turnover in the alveolar wall surrounding the root, which reduction is corrected by treatment with insulin.     

Alveolar wound healing and ridge remodeling after tooth extraction in the rat: a histologic, radiographic, and histometric study

Healing of extraction wounds in rats was analyzed by histologic, radiographic and histometric methods at 0, 7, 14, 30, 60 days after tooth removal. Total alveolar volume, volume density of bone, percentage of bone formation, bone resorption areas, and height of both vestibular and lingual crests were analyzed. Total alveolar bone volume and bone density in the apical third increased from 0 to 60 days. Maximum bone formation was observed at 14 days, whereas the greatest bone resorption was observed seven days after extraction. The height of the lingual crest was lowest 14 days postextraction and then increased progressively to day 60.     

Effects of alendronate on bone healing after tooth extraction in rats

Oral Diseases (2010) 16 , 674–685 Objectives: Tooth extraction has been identified as an important risk factor for bisphosphonate‐induced osteonecrosis of the jaw. Therefore, the main goal of this study was to determine the effects of alendronate on healing of the extraction socket and on interdental alveolar bone after tooth extraction in rats. Materials and methods: Animals were injected subcutaneously with vehicle or alendronate for 3–4 weeks before the first mandibular molar was extracted and these treatments were continued during post‐extraction periods of 10, 21, 35 and 70 days. Mandibles were processed to evaluate healing of the extraction socket and adjacent alveolar bone by assessing bone formation, bone resorption and vascularity by histomorphometric techniques. Results: Alendronate decreased new woven bone formation, blood vessel area, perimeter and number in the extraction socket at 10 days postextraction, but not at later time points. Furthermore, alendronate‐treated rats had increased interdental alveolar bone volume and height only at 10 days postextraction. In addition, a 2.5‐fold increase in the percentage of empty osteocyte lacunae was found in alveolar bone of alendronate‐treated rats only at 10 days postextraction. Conclusions: Alendronate transiently decreases bone formation and vascularity in the extraction socket and delays the removal of interdental alveolar bone after tooth extraction in rats.     

The effect of alendronate on resorption of the alveolar bone following tooth extraction

Maintenance of alveolar bone width and height following tooth loss is essential with regard to the restoration of missing teeth with endosseous dental implants or prosthodontics approaches. A various amount of alveolar ridge resorption is likely to occur after tooth extraction at the buccal and lingual alveolar bone plates. Bisphosphonates, alendronate, is well known for its potent inhibition of osteoclast-mediated bone resorption. The objective of this study was to examine the inhibitory effect of alendronate on alveolar bone resorption following tooth extraction in rats. Male Wistar Albino rats were divided into three groups: baseline group, saline-treated group and alendronate-treated group. The saline-treated group was administered with daily saline solution for 2 and 4 weeks respectively while the alendronate-treated group was given a daily amount of 0.25 mg/kg alendronate subcutaneously for the same periods. The level of urinary calcium, creatinine, and serum calcium, alkaline phosphatase and phosphate were measured. Serum alkaline phosphatase level was measured as a marker of osteoblastic activity. Histopathological sections of 4 microm thickness were obtained from the right first mandibular molar region in a bucco-lingual direction. The number of osteoclasts, osteoblasts, and haversian canals, the number and size of resorptive lacunae, and osteoid formation were evaluated histopathologically. The mean thickness of buccal and lingual alveolar bone was measured. In the alendronate-treated group, both buccal and lingual alveolar bone volume reduction was significantly less than the saline treated group. Significant reduction in serum and urinary calcium levels and the number of osteoclasts revealed the pronounced suppression of bone resorption in the alendronate-treated group.     

The influence of short-term diabetes mellitus and insulin therapy on alveolar bone loss in rats

BACKGROUND: It is well known that the multiple direct and indirect consequences of hyperglycemia in diabetic individuals have been linked to a number of abnormal host effector mechanisms that could lead to an increased risk of developing periodontal disease. OBJECTIVE: The aim of this study was to investigate the effect of short-term experimental diabetes and insulin therapy on the severity of alveolar bone loss in rats, and the effect of experimental periodontitis on glycemic control. METHODS: Seventy-two male Wistar rats were divided into four groups: group I animals were submitted to dental ligature around lower right first molars (ligated); group II consisted of streptozotocin (STZ)-diabetic, ligated rats; group III represented STZ-diabetic, unligated rats; and group IV consisted of insulin-treated (6 U/day), STZ-diabetic, ligated rats. Blood glucose of all diabetic rats was monitored at regular intervals. Standardized digital radiographs were taken after killing at 7, 15 and 30 days to measure the amount of bone loss about the mesial root surface of the first molar tooth in each rat. Results: No significant (p < 0.05) changes in plasma glucose levels of insulin-treated diabetic rats were found among the different examinations after the beginning of insulin therapy. Rats from group II showed significantly greater increases in mean plasma glucose levels at 15 and 30 days after ligature placement compared with rats from group III (p < 0.05). Furthermore, in spite of the significant alveolar bone loss progression that was observed in groups I, II and IV (p < 0.00001; two-way anova), no significant differences among these groups regarding the severity of bone loss (p = 0.77) and no significant interaction between treatment group and time (p = 0.81) were found. CONCLUSIONS: Within the limits of this study, it can be suggested that the severity of periodontal disease was not affected by short-term diabetes, and that experimental periodontitis increased blood glucose levels in uncontrolled diabetic rats.