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.     

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.     

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.     

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.     

雌激素缺乏对大鼠牙槽骨吸收影响的实验研究

目的观察雌激素缺乏对大鼠牙槽骨吸收的影响。方法34只雌性SD大鼠随机分为4组。第1组假手术(n=8),第2组卵巢切除(n=9),第3组卵巢切除加牙周结扎(n=9),第4组卵巢切除、牙周结扎加雌激素治疗(n=8)。适应性喂养7天后行假手术或双侧卵巢切除术。第4组于术后第二天起皮下注射苯甲酸雌二醇．20μg／kg体重／次,三天一次。第3、4两组于卵巢切除术后28天,结扎丝结扎上颌第一磨牙诱导牙周炎。第63天处死全部大鼠。常规取材。观察牙用组织组织学改变。测量牙用骨丧失值(PBL)。比较牙用骨支持率(PBS)。检测血清碱性磷酸酶(ALP)。结果采用成组f检验,第1、2两组的PBL分别为0．398±O．147mm,0．663±0．132哪。PBS分别为O．588±O．058。0．440±0．197,组间差异均有统计学意义(P<0．05);第2、3两组的PBL、PBS组间差异均有统计学意义(P<0．05)。第3组的PBL为0．875±0．197mm,PBS为0．336±O．087;第3、4两组的PBL、PBS组间差别没有统计学意义(P>0．05),第4组的PBL为O．823±0．119mm,PBS为0．360±0．950。结论雌激素缺乏促进牙槽骨吸收,茵斑刺激加剧骨质疏松大鼠牙槽骨的吸收,雌激素替代治疗不能预防骨质疏松大鼠因茵斑刺激引发的牙槽骨吸收。     

Comparison of the reproducibility of storage phosphor and film bitewings for assessment of alveolar bone loss

Objective. To compare bitewing storage phosphor images and a digital measuring method with bitewing films and an analog measuring method with regard to the reproducibility of measurements of alveolar bone loss. Material and methods. Nine participants randomly selected from an epidemiological study were radiographically examined using two modalities: bitewing SP images and bitewing films. A digital measuring method was used on the bitewing SP images and an analog measuring method on the bitewing films. Alveolar bone loss was measured at 12 index sites in the premolar/molar region per participant and modality. One hundred measured sites on each modality were assessed twice by three observers. Paired t-test values and intra-class correlation coefficient (ICC) were computed. Results. Comparison of the mean absolute difference of alveolar bone loss between the digital and analog measuring methods demonstrated comparable results (p=0.53). The absolute difference in millimetres between 1st and 2nd measurements was comparable for two observers and statistically different for one. Intra-observer performance between 1st and 2nd measurements was comparable for the digital (ICC=0.85) and analog (ICC=0.83) measuring methods. Inter-observer agreement for the digital measurements was higher (ICC=0.79) than for the analog measurements (ICC=0.64). Conclusions. The study demonstrates that digital and analog measuring methods are comparable with regard to absolute alveolar bone measurements and intra-observer agreement. Inter-observer comparison demonstrated significantly higher agreement for the digital measurements. Based on the overall results, the modalities with the measuring methods utilized are comparable when measuring minor alveolar bone loss.     

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.     

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目的研究能够快速建立稳定、可靠、重复性好的大鼠实验性牙周炎模型的方法,摸索建模的最佳时间并对比研究结扎与非结扎区域的牙槽骨破坏情况。方法本研究于2010年7月至2011年1月在中国医科大学基础医学院微生物学实验室及口腔医学院中心实验室完成。将18只SD大鼠随机分为对照组和4周、8周实验组。采用牙颈部结扎合并口腔接种牙周致病菌的方法,建立大鼠实验性牙周炎模型。分别于4周、8周时进行牙周检查,并利用放射影像和体视显微镜检查对比大鼠的牙周骨组织破坏情况。结果4周和8周实验组大鼠结扎区都出现牙龈红肿,探诊出血,均可探及较深的牙周袋。对照组和4周、8周实验组大鼠上颌三颗磨牙平均骨丧失量分别为（357．63±284．96）μm、（929．56±366．43）μm和（941．80±354．87）μm。与对照组相比,4周和8周实验组大鼠上颌磨牙的骨丧失量均显著增加,差异有统计学意义（P〈0．05）,但4周与8周实验组之间差异无统计学意义（P〉0．05）。结论采用牙颈部结扎合并口腔接种牙周致病菌的方法,4周左右即可形成稳定可靠的大鼠牙周炎模型。大鼠的牙周骨破坏在4周之后速度减缓。     

Analysis of cathepsin-K activity at tooth and dental implant sites and the potential of this enzyme in reflecting alveolar bone loss

Background: Cathepsin‐K is an enzyme involved in bone metabolism which may make this feature important for both natural teeth and dental implants. The aims of the present study are to comparatively analyze the gingival crevicular fluid (GCF)/peri‐implant sulcus fluid (PISF) cathepsin‐K levels of natural teeth and dental implants, and to assess the potential relationship between this biochemical parameter and alveolar bone loss around natural teeth and dental implants. Methods: Probing depth, bleeding on probing, gingival index, and plaque index clinical parameters were assessed, and GCF/PISF samples were obtained from natural teeth/dental implants presenting with either clinical health, gingivitis/peri‐implant mucositis, or chronic periodontitis/peri‐implantitis. Cathepsin‐K activity levels of 42 GCF samples and 54 PISF samples were determined, and marginal bone loss (MBL) measures were calculated from digitalized standardized intraoral periapical radiographs obtained from natural teeth and dental implants by using cemento‐enamel junction and the actual distance between two consecutive threads of the dental implant as reference points for natural teeth and dental implants, respectively. Results: Comparing the natural teeth group with dental implant group with regard to MBL measure, cathepsin‐K activity, and GCF/PISF volume revealed no significant differences. In both natural teeth and dental implant groups, despite higher MBL measures, cathepsin‐K activity, and GCF/PISF volumes with the presence of inflammation, it was the presence of alveolar bone loss that lead to significantly higher values for these parameters. Conclusion: We suggest cathepsin‐K as a biochemical parameter for monitoring periodontal/peri‐implant alveolar bone loss.     

淫羊藿苷口服给药对骨质疏松牙周炎小鼠牙槽骨吸收的影响

目的:研究口服淫羊藿苷（ICA）对骨质疏松小鼠牙周炎引起的牙槽骨吸收的抑制作用。方法:3月龄、雌性、C57BL/6J小鼠随机分为3组,即正常组（SHAM组）、卵巢切除+口腔涂布牙龈卟啉单胞菌（Pg）+淫羊藿苷组（OVX+Pg+ICA）、卵巢切除+Pg口腔涂布组（OVX+Pg）。小鼠适应性喂养1周,第2周进行双侧卵巢切除术,诱导小鼠骨质疏松形成。从第4周开始,对小鼠牙周涂布Pg,1次/d,连续1周。第12周收集左侧下颌骨进行固定切片及染色,分析各组之间牙槽骨吸收高度的差异。收集右侧下颌骨进行亚甲蓝染色,分析各组间牙槽骨吸收面积的差异;收集双侧上颌骨牙周组织蛋白,分析成骨相关蛋白的表达差异。采用SPSS16.0软件包对数据进行统计学分析。结果:小鼠股骨及牙周组织切片染色显示,成功建立了小鼠骨质疏松牙周炎模型。对牙槽骨吸收距离和面积的测量分析显示,相比于OVX+Pg组,口服淫羊藿苷可显著减少釉-牙骨质界-牙槽嵴顶（CEJ-ABC）的距离及颊舌侧牙槽骨吸收面积（P<0.05）;Western免疫印迹显示,相比于OVX+Pg组,OVX+Pg+ICA组中Runx2、OSX、OCN及OPN蛋白表达水平显著升高（P<0.05）。结论:口服淫羊藿苷在预防小鼠骨质疏松发生的同时,可有效减少牙周炎引起的牙槽骨吸收。     

A novel murine model for chronic inflammatory alveolar bone loss

Oz HS, Ebersole JL. A novel murine model for chronic inflammatory alveolar bone loss. J Periodont Res 2009; doi: 10.1111/j.1600-0765.2009.01207.x. © 2009 John Wiley & Sons A/S
Background and Objective:  Chronic inflammatory bowel disease (IBD) demonstrates some similarities to the dysregulated chronic immunoinflammatory lesion of periodontitis. Trinitrobenzene sulphonic acid (TNBS) and dextran sodium sulphate (DSS) administered to rodents have been shown to elicit inflammatory responses that undermine the integrity of the gut epithelium in a similar manner to IBD in humans. The objective of this study was to evaluate the ability of these chemicals to elicit periodontal inflammation as a novel model for alveolar bone loss.
Material and Methods:  Mice were treated by oral application of TNBS twice a week, or with DSS in the diet over a period of 18 weeks. Alveolar bone loss was assessed on the defleshed skull using morphometric measures for area of bone resorption.
Results:  The TNBS-treated animals tolerated oral administration with no clinical symptoms and gained weight at a similar rate to normal control animals. In contrast, DSS exerted a systemic response, including shortening of colonic tissue and liver enzyme changes. Both TNBS and DSS caused a localized action on periodontal tissues, with alveolar bone loss observed in both maxilla and mandibles, with progression in a time-dependent manner. Bone loss was detected as early as week 7, with more severe periodontitis increasing over the 18 weeks ( p  < 0.001). Young (7-month-old) and old (12-month-old) mice with severe combined immunodefiency were treated with TNBS for a period of 7 weeks and did not develop significant bone loss.
Conclusion:  These data show that oral administration of TNBS or DSS provokes alveolar bone loss in concert with the autochthonous oral microbiota.     

Enhanced alveolar bone loss in a model of non-invasive periodontitis in rice rats

Oral Diseases (2012) 18 , 459–468 Objective: The rice rat (Oryzomys palustris) develops periodontitis‐like lesions when fed a diet rich in sucrose and casein (H‐SC). We aimed to establish whether this model can accurately mimic the development of human periodontitis. Materials and Methods: For this purpose, 28‐day‐old rice rats (15/group) were assigned to standard (STD) or H‐SC diets and sacrificed after 6, 12, and 18 weeks. Jaws were processed for morphometric, histometric, histologic, histomorphometric, and micro‐CT analyses. Results: We found a progressive increase in horizontal alveolar bone loss (ABL) with age in maxillae of rats fed the STD diet as determined by morphometry. The H‐SC diet exacerbated horizontal ABL at the palatal surface at 12 and 18 weeks. Furthermore, increased vertical ABL was detected in mandibles and maxillae of rats fed the H‐SC diet for 12 and/or 18 weeks by histometry and micro‐CT. Remarkably, the H‐SC diet significantly increased bone remodeling at the interproximal alveolar bone of mandibles from rats fed for 6 weeks, but not in those fed for longer periods. Conclusions: These findings indicate that the H‐SC diet induced a transient increase in alveolar bone remodeling, which is followed by ABL characteristic of moderate periodontitis.     

Validation of a dental image analyzer tool to measure alveolar bone loss in periodontitis patients

Background and Objective:  Radiographs are an essential adjunct to the clinical examination for periodontal diagnoses. Over the past few years, digital radiographs have become available for use in clinical practice. Therefore, the present study investigated whether measuring alveolar bone loss, using digital radiographs with a newly constructed dental image analyzer tool was comparable to the conventional method, using intra-oral radiographs on film, a light box and a Schei ruler.
Material and Methods:  Alveolar bone loss of the mesial and distal sites of 60 randomly selected teeth from 12 patients with periodontitis was measured using the conventional method, and then using the dental image analyzer tool, by five dentists. The conventional method scored bone loss in categories of 10% increments relative to the total root length, whereas the software dental image analyzer tool calculated bone loss in 0.1% increments relative to the total root length after crucial landmarks were identified.
Results:  Both methods showed a high interobserver reliability for bone loss measurements in nonmolar and molar sites (intraclass correlation coefficient ≥ 0.88). Also, a high reliability between both methods was demonstrated (intraclass correlation coefficient nonmolar sites, 0.98; intraclass correlation coefficient molar sites, 0.95). In addition, the new dental image analyzer tool showed a high sensitivity (1.00) and a high specificity (0.91) in selecting teeth with ≥ 50% or < 50% alveolar bone loss in comparison with the conventional method.
Conclusion:  This study provides evidence that, if digital radiographs are available, the dental image analyzer tool can reliably replace the conventional method for measuring alveolar bone loss in periodontitis patients.     

壳寡糖对牙周炎大鼠牙槽骨吸收及Th17/Treg平衡和OPG/RANKL/RANK通路的影响

目的: 探讨壳寡糖对牙周炎大鼠牙槽骨吸收及Th17/Treg平衡和OPG/RANKL/RANK通路的影响。方法: 建立牙周炎大鼠模型,随机分为模型组、壳寡糖低剂量组、壳寡糖中剂量组、壳寡糖高剂量组和甲硝唑组,每组12只,另取12只作为对照组。分组处理后,评估牙龈指数、牙槽骨吸收值;H-E染色观察牙周组织病理形态学变化;流式细胞术检测外周血中Th17/Treg细胞比值;酶联免疫吸附试验（ELISA）检测各组大鼠血清中IL-17、TGF-β、RANKL、OPG水平,实时荧光定量PCR（qRT-PCR）检测各组大鼠牙周组织OPG、RANKL mRNA表达水平。采用SPSS 24.0软件包对数据进行统计学分析。结果: 与对照组相比,模型组大鼠牙周组织呈现牙周膜纤维束断裂、排列紊乱,毛细血管扩张、增生,炎症细胞浸润等病理损伤;牙龈指数、牙槽骨吸收值、Th17/Treg比值、血清RANKL及IL-17水平、牙周组织RANKL mRNA水平显著升高（P<0.05）,血清OPG及TGF-β水平、牙周组织OPG mRNA水平显著降低（P<0.05）。与模型组相比,壳寡糖低、中、高剂量组和甲硝唑组大鼠牙周组织病理损伤减轻;牙龈指数、牙槽骨吸收值、Th17/Treg比值、血清RANKL及IL-17水平、牙周组织RANKL mRNA水平显著降低（P<0.05）,血清OPG及TGF-β水平、牙周组织OPG mRNA水平显著升高（P<0.05）,且壳寡糖各组呈剂量依赖性,壳寡糖高剂量组与甲硝唑组相比,差异无统计学意义（P>0.05）。结论: 壳寡糖可促使Th17/Treg平衡恢复正常,上调OPG表达,下调RANKL表达,抑制牙周炎大鼠牙槽骨吸收,改善其临床症状。     

Prevalence of periodontitis based on retrospective radiographic evaluation at dental hospital in Eastern Province of Saudi Arabia: A retrospective study

ObjectivesThe contemporary information on the prevalence of periodontitis and associated risk factors is deficient in the Kingdom of Saudi Arabia. Our aim was to measure the prevalence of periodontitis and associated risk factors among the Saudi population in the Eastern Province of Saudi Arabia who visited the University Dental Hospital.MethodsIn this retrospective study, the demographic data and medical and dental records of 700 subjects were examined. Bitewing radiographs were analyzed to measure the alveolar bone loss in posterior teeth by measuring the distance between the cementoenamel junction and the crest of the alveolar bone. A chi-square test was performed to compare the severity of periodontitis. A comparison of multivariate mean bone loss was performed using a t-test. Logistic regression analysis was used to evaluate the predictors of periodontitis. A P-value equal to or under 0.05 reflected statistical significance.ResultsAmong 700 cases, the patients’ mean age was 35.6 ± 12.1; 52.6 % were male and 47.4 % were female. Overall periodontitis prevalence was 52.1 %. The distribution of mild, moderate, and severe periodontitis prevalence was 36.1 %, 14.1 %, and 1.8 %, respectively. The severity of periodontitis was statistically similar between males and females (p = 0.148); however, significantly more Saudi than non-Saudi patients had moderate periodontitis. Higher proportions of severe periodontitis were seen in the age group of over 50-years-old (p < 0.001) and in patients with poor oral hygiene (p < 0.001), diabetes mellitus (p < 0.005), and hypertension (p < 0.002). Six total predictors of periodontitis were depicted, i.e., age > 50 years (OR = 3.73), poor OH status (OR = 2.24), BOP (OR = 3.35), presence of plaque (OR = 2.61), diabetes mellitus (OR = 3.19), and hypertension (OR = 3.62).ConclusionThe primary factors associated with the prevalence of periodontitis were age, nationality, diabetes, hypertension, BOP, plaque, and OH status. However, no association was observed between gender or cardiovascular disease and the prevalence of periodontitis in the studied population.     

Wnt3a促进牙周膜干细胞成骨分化及实验性牙周炎牙槽骨再生的研究

目的:探究Wnt3a对人牙周膜干细胞（periodontal ligament stem cell,PDLSC）增殖、迁移和成骨分化的影响,确定Wnt3a对小鼠实验性牙周炎牙槽骨再生的作用。方法:分别用不同质量浓度的Wnt3a（0、20、100、200、500 μg/L）刺激PDLSC（计为5组）,培养2、4、7或10...     

Effect of cyclosporin A on alveolar bone homeostasis in a rat periodontitis model

OBJECTIVES: The administration of cyclosporin A has been associated with significant bone loss and increased bone remodeling. The present investigation was designed to evaluate the effects of cyclosporin A on alveolar bone of rats subjected to experimental periodontitis, using serum, stereometric and radiographic analysis. METHODS: Twenty-four rats were divided into one of the following groups with six animals each: group I, control rats; group II, in which the animals received a cotton ligature around the lower first molars; group III, in which the rats received a cotton ligature around the lower first molars and were treated with 10 mg/(kg body weight day) of cyclosporin A; group IV, in which the rats were treated with 10 mg/(kg body weight day) of cyclosporin A. At the end of experimental period, at 30 days, animals were killed and the serum calcium and alkaline phosphatase levels were measured in all groups. The distance from the alveolar bone crest to the cemento-enamel junction was measured radiographically for each mesial surface of the lower first molars of each rat. After histological processing, the stereological parameters: volume densities of multinucleated osteoclasts (V(o)), alveolar bone (V(b)), marrow (V(m)), and relation of eroded surface/bone surface (Es/Bs) were assessed at the mesial region of the alveolar bone. RESULTS: Significant decreases in serum calcium were observed in those groups that received cyclosporin A therapy. No significant changes in serum alkaline phosphatase were observed. The therapy with cyclosporin A combined with the ligature placement decreased the V(b) and increased the V(o), V(m) and Es/Bs at the mesial surface of lower first molars. On the other hand, the radiographic data showed that cyclosporin A therapy diminished the alveolar bone loss at the mesial surface of the lower first molars. CONCLUSIONS: Therefore, within the limits of this study, we suggest that cyclosporin A at immunosuppressive levels can bring about an imbalance in the alveolar bone homeostasis in rats. However, in the presence of inflammatory stimulation, the inhibition of the immune system by cyclosporin A may decrease the initial periodontal breakdown.     

不同矫治技术对牙周炎患者上切牙区牙槽骨改变的影响

目的： 探讨不同矫治技术治疗牙周炎对患者上切牙区牙槽骨密度、高度及龈沟出血变化的影响。方法： 选取2016年1月—2019年12月萍乡市人民医院口腔科行正畸治疗的中度牙周炎患者23例,按照随机数字表法分为实验组（n=12）和对照组（n=11）,实验组采用无托槽隐形矫治器治疗,对照组采用常规唇侧固定矫治器治疗,比较2组治疗前、后龈沟出血指数、探诊深度、上切牙区牙槽骨骨高度和骨密度变化。采用SPSS 22.0软件包对数据进行统计学分析。结果： 治疗后2组上切牙区腭侧牙槽嵴顶处（L1）骨密度降低,实验组下降率显著小于对照组（P<0.05）。治疗后对照组上切牙区解剖根尖点冠方1 mm处（L3）骨密度显著减低,但实验组无明显变化。治疗前、后2组上切牙区牙槽骨高度无显著变化（P>0.05）。实验组上切牙牙根吸收程度显著低于对照组（P<0.05）。实验组上切牙压入量显著高于对照组（P<0.05）。治疗后2组探诊深度、龈沟出血指数均降低,且实验组变化量显著大于对照组（P<0.05）。结论： 采用无托槽隐形矫治器治疗牙周炎,较常规唇侧固定矫正更有利于上切牙区牙槽骨骨密度恢复,且两者对骨高度影响相同,两者均为安全有效的正畸治疗方式。     

雷洛昔芬对牙周炎合并系统性绝经后骨质疏松症小鼠模型局部牙槽骨破坏的影响

目的：探讨雷洛昔芬对牙周炎合并系统性绝经后骨质疏松症（PMO）小鼠模型局部牙槽骨破坏的影响。方法：无特定病原级雌性成熟Wistar小鼠,适应性喂养7 d 后,随机分为空白组（保留两侧卵巢,只切除卵巢组织周围与卵巢重量相当的脂肪组织）、对照组（切除两侧卵巢+口腔正畸结扎丝结扎）、实验组（切除两侧卵巢+口腔正畸结扎丝结扎+雷洛昔芬试剂）,每组各15只。术后4周拍摄CT,检测骨密度和骨吸收情况,体视显微镜观察牙槽骨破坏情况,酶联免疫吸附测定法（ELISA）检测破骨相关因子白细胞介素1(IL-1)、IL-1α、转化生长因子(TGF)、肿瘤坏死因子α(TNF-α)、TNF-β的表达水平。采用SPSS 18.0软件包对数据进行统计学分析。结果：对照组新骨形成少于实验组。亚甲蓝染色结果显示,对照组小鼠骨显著吸收,体视显微镜下可见骨破坏,实验组小鼠骨吸收程度较轻。与空白组相比,对照组、实验组牙槽骨密度降低而牙槽骨丧失、IL-1、IL-1α、TGF、TNF-α、TNF-β显著升高（P<0.05）;对照组牙槽骨密度显著低于实验组（P<0.05）,牙槽骨丧失、IL-1、IL-1α、TGF、TNF-α、TNF-β显著高于实验组（P<0.05）。结论：雷洛昔芬可减少PMO牙周炎症小鼠牙槽骨吸收、破骨细胞因子表达,防止牙槽骨破坏而有效防止牙周炎进展。