体外培养的人牙龈牙周膜牙髓纤维细胞生长及形态特点

牙龈、牙周膜、牙髓组织体外培养结果只有纤维细胞生长,培养成功率分别为20/20、4/20和4/52,最高传代代数为50、20和18,最高传代者生长稳定期为5～40、5～15和5～12代,生长稳定期倍增时间为44、70和90h。在倒置和光学显微镜下观察3种来源的细胞无明显差别,电镜观察显示牙龈纤维细胞两端有许多微细突起,细胞器较发达,含丰富糖原颗粒;牙周膜纤维细胞两端微细突起较少,细胞中糖原颗粒较多,有空泡样结构;牙髓纤维细胞两靖微细突起少,细胞中糖原颗粒少,空泡样结构多。     

牙槽骨降低对牙周膜内应力的影响

为了解牙齿的牙槽骨降低对牙周膜内应力的大小和分布的影响规律,本文建立了一包括第二双尖牙和第二磨牙的下颌骨段的三维有限元模型,模拟牙齿在咀嚼时的受力状况进行加载,计算分析了牙槽骨为五种不同的高度水平时牙周膜内的应力值。计算结果表明:牙周膜内的应力随牙槽骨降低而逐渐增大,但在牙周膜的不同部位应力增加的幅度不同。牙周膜内应力的增加与牙槽骨降低之间的关系不是线性的,牙槽骨吸收在根长的20％以内时应力的增长较平缓,牙槽骨吸收超过根长的20％以后应力的增加幅度明显加大。     

IL—6对人牙髓细胞,牙周膜细胞生长影响的实验研究

目的：了解ＩＬ－６对构成牙髓、尖周组织主要细胞生长的影响，揭示ＩＬ－６在牙髓、尖周病变过程中的作用。方法：应用细胞培养技术，采用ＭＴＴ比色法进行细胞生长及存活状态测定。结果：ＩＬ－６抑制牙髓细胞、牙周膜细胞的生长，并呈时间和剂量依赖关系，两细胞间无显著差异。结论：ＩＬ－６可能对牙髓、尖周组织损伤的修复和代谢功能有一定影响     

人牙龈上皮细胞上清液对牙髓细胞增殖及分化影响的研究

目的:研究体外培养的人牙龈上皮细胞(human gingival epithelium cells,HGECs)上清液对人牙髓细胞(human dental pulp cells,HDPCs)增殖及分化的影响,探讨在体外建立HGECs和HDPCs共培养模型的可行性。方法:采用组织块法分别进行HGECs和HDPCs原代培养,收集第2、4、6d的HGECs上清液,均以10%、30%、50%浓度作用于HDPCs,MTT法测定HDPCs增殖情况,通过测定细胞裂解液中ALP水平研究对HDPCs分化的影响,以加入相应浓度的上皮细胞培养基K-SFM为对照。结果:加入不同浓度的第2、4、6d的HGECs上清液后HDPCs的增殖均上升,并有促进HDPCs分化的作用,而对照组则抑制了HDPCs增殖和分化。结论:体外培养HGECs的上清液能够促进HDPCs增殖和分化。     

牙龈卟啉单胞菌牙龈蛋白酶K对人牙周膜细胞增殖的影响

目的 探讨牙龈卟啉单胞菌牙龈蛋白酶K对人牙周膜细胞增殖的影响.方法 组织块法体外培养人牙周膜细胞,不同浓度的牙龈蛋白酶K作用于人牙周膜细胞24h,对照组为无牙龈蛋白酶K作用的人牙周膜细胞.浓度为12.5μg/ml牙龈蛋白酶K分别作用于人牙周膜细胞24、48、72、96h,对照组也培养相同的时间.采用MTT法检测人牙周膜...     

人牙骨质,牙周膜,牙槽骨中Ⅰ,Ⅲ,型胶原的检测

本研究目的为检测人牙骨质、牙周膜和牙槽组织中Ⅰ、Ⅲ、Ⅳ型胶原的分布和含量。应用免疫组化和图像分析法测得：Ⅰ型胶原占牙周膜的７８．０６％、牙骨质的７３．０９％和牙槽骨的３０．５０％；Ⅲ型胶原占牙周膜的１１．７３％，在根尖部牙骨质和相对应的牙槽窝骨组织也观察到Ⅲ型胶原；４型胶原仅见于血管基膜。     

GM-CSF对牙周膜和牙髓成纤维细胞的生物学作用

目的 :观察GM -CSF对牙周膜成纤维细胞、牙髓成纤维细胞的生物学作用。方法 :原代培养牙髓成纤维细胞、牙周膜成纤维细胞 ,用MTT法测定细胞增殖 ,酶动力学方法测定ALP活性。结果 :在观察期 (3～7d)GM -CSF可使两种细胞出现明显的增殖 ,而不能诱导ALP的表达。结论 :GM -CSF的浓度在 0 .0 0 1～ 1mg/L之间对牙周膜成纤维细胞、牙髓成纤维细胞有明显的增殖效应 ,大于 1mg/L时对增殖有明显的抑制作用。     

牙周膜和牙槽骨牵张成骨术加速正畸牙移动

牙周膜牵张成骨（PDLD）和牙槽骨牵张成骨（DAD）是牵张成骨术在加速正畸牙移动方面应用的具体技术,本文就PDLD和DAD术式,PDLD和DAD的基本原理,牵张过程与牙体移动特点,支抗牙移动,牙体在新骨区的移动,牵张过程中的牙周组织变化,牵张过程中的不利及不确定因素等研究进展作一综述。     

CD14在牙髓和牙龈组织中的免疫组化定位

目的：检测CD14在牙髓和牙龈组织的分布，探讨CD14在牙髓和牙龈炎症过程中的可能作用。方法：组织切片技术制备人牙髓和牙龈组织标本，用免疫组织化学方法检测CD14在健康和炎症牙髓、牙龈组织的分布。结果：健康牙髓没有发现CD14免疫阳性细胞，炎性牙髓组织病灶处炎细胞呈阳性反应；健康牙龈上皮棘层细胞有微弱的阳性反应，炎性牙龈上皮棘细胞层强阳性。结论：CD14参与了牙髓和牙龈组织的炎症反应过程；特别是牙龈上皮棘细胞层CD14免疫阳性，说明棘细胞层可能参与了牙龈炎免疫病理过程。     

牙龈卟啉单胞菌诱导的耐受对小鼠牙槽骨吸收的影响

目的：研究牙龈卟啉单胞菌（P.gingivalis）诱导的耐受对小鼠骨吸收相关因子IL-1β、骨保护素（OPG）/NF-κB受体激活蛋白配体（RANKL）表达水平,以及牙槽骨吸收的影响。方法：采用1×109 CFU P.gingivalis口内涂布给菌5 d,磷酸盐缓冲液（PBS）洗脱后,再次口内涂布P.gingivalis给菌2 d,构建Balb/c小鼠牙周组织耐受模型。10 d后收集新鲜牙龈组织,采用western bolt检测牙龈组织中IL-1β、OPG和RANKL表达水平的变化。6周后,收集上颌骨,采用亚甲基蓝染色法检测牙槽骨吸收水平的改变。结果：耐受组小鼠牙龈组织中IL-1β表达水平较非耐受组降低,OPG/RANKL比值较非耐受组升高。亚甲基蓝染色结果显示,耐受组小鼠釉牙骨质界至牙槽嵴顶（ABC-CEJ）的距离小于非耐受组（P＜0.01）,说明耐受组小鼠牙槽骨吸收较非耐受组降低。结论：P.gingivalis诱导小鼠牙周组织耐受后,小鼠牙龈组织中骨吸收相关因子IL-1β分泌降低,OPG/RANKL比值升高,抑制了牙槽骨吸收。     

唑来磷酸对实验性牙槽骨吸收抑制作用的研究

目的:在实验性牙槽骨吸收动物模型基础上,研究唑来磷酸局部应用对实验性牙槽骨吸收的影响,旨在找出一种效果理想的防治牙槽骨吸收的局部应用药物,为其局部应用于临床提供实验依据。方法:40只SD大鼠,随机分为5组,每组8只,一组为正常对照组,其余4组为实验组,分别为造模对照组、唑来磷酸低剂量、中剂量和高剂量治疗组(0.8mg/mL,1.0mg/mL和1.2mg/mL);实验组均采用牙周翻瓣术建立牙槽骨吸收模型,治疗组在翻瓣局部处分别给予不同浓度的唑来磷酸药物。所有大鼠在给药21天后处死,取牙体牙周组织标本,进行X线片拍摄、常规病理切片观察。结果:低剂量组、中剂量组和高剂量组牙槽骨吸收程度明显低于造模对照组,差异有统计学意义(P<0.05);牙槽骨病理切片显示中剂量组和高剂量组破骨细胞数量均较造模对照组明显减少(P<0.05);且骨小梁面积均优于造模对照组(P<0.05)。结论:唑来磷酸局部应用对牙周翻瓣术诱导的牙槽骨吸收具有一定的抑制作用。     

The significance of alveolar bone in periodontal disease

The periodontal conditions in 19 patients with unilateral cleft lip, alveolus and palate (CLAP) and in 6 patients with bilateral CLAP, were evaluated in 1979 and re-examined in 1987. During these 8 years, these patients were not subjected to any professionally supervised maintenance care program. Pronounced plaque accumulation and high frequency of gingival units exhibiting bleeding on probing were noted in the majority of the patients both in 1979 and 1987, documenting inadequate oral hygiene standards with resulting inflammatory reactions of the periodontal tissues. Progression of periodontal disease over time was assessed as loss of clinical attachment and loss of alveolar bone height. The periodontal destruction was not found to be more severe at cleft sites with a long connective tissue attachment than at control sites not affected by cleft defects. It was concluded that sites with a long supracrestal connective tissue attachment do not seem to be more prone to periodontal destruction, induced by bacterial infection, than sites with a normal length of the supraalveolar fibrous attachment. The results also show that the alveolar bone height, as visualized in radiographs at sites with alveolar defects, is of limited value for the diagnosis of the degree of periodontal destruction at such sites.     

义龈修复与牙周菌群变化相关性研究

目的 :通过对牙周菌群在两种义龈修复前后的种属变化探讨义龈修复对严重牙龈退缩患者修复治疗的远期效果及与牙周健康的关系。方法 :严重的牙龈退缩患者经过系统性牙周治疗后随机分为常规义龈修复组及弹性义龈修复组 ,分别提取修复治疗前后各观察时段内龈沟液 ,作细菌培养和分类计数观察。结果 :对细菌形态学的记数比较显示 ,弹性材料组的螺旋体及梭杆菌的改变较常用热凝塑料组慢 ,修复 6个月后才能检测出显著性差异 ,常规材料修复 1个月后即可发现显著性变化 ;对几种特异性的牙周厌氧菌的分类培养显示在常规材料组组内差异明显 ,随时间的延长 ,组间差异更加明显。结论 :弹性塑料由于材料组织相容性好等优点 ,制作的义龈对于患者牙周健康的保持更为有利 ,是一种较为满意的治疗严重牙龈退缩的修复方法     

Cytomegalovirus periodontal presence is associated with subgingival Dialister pneumosintes and alveolar bone loss

Destructive periodontal disease is associated with human cytomegalovirus (HCMV), Epstein-Barr type 1 virus (EBV-1) and other members of the Herpesviridae family as well as with various gram-negative anaerobic bacteria, including the Dialister pneumosintes species. This study aimed to determine possible interrelationships between periodontal HCMV, EBV-1, herpes simplex virus and D. pneumosintes, and relate the microbiological findings to periodontitis clinical status. Sixteen subjects each contributed paper point samples from two progressing and two stable periodontitis lesions, as determined by ongoing loss of probing attachment. Polymerase chain reaction methodology was used to identify the study herpesviruses and D. pneumosintes. Chi-squared tests, Fisher exact tests and multivariate logistic regression were employed to identify statistical associations among herpesviruses, bacteria and clinical variables. HCMV, and no other virus or combination of viruses, was positively associated with the presence of D. pneumosintes, and the relationship was specific for individual periodontitis sites with no detectable subject effect. D. pneumosintes was in turn positively associated with periodontal pocket depth and disease-active periodontitis. When the average percentage of alveolar bone loss in all teeth was treated as a response, HCMV remained significant even after D. pneumosintes was included in the model, suggesting that both HCMV and D. pneumosintes affected bone loss or, alternatively, HCMV affected factors not studied that themselves can induce bone loss. We hypothesize that periodontal HCMV sets the stage for subgingival proliferation of D. pneumosintes and subsequent periodontal disease progression. Studies on herpesviral-bacterial interactions may hold great promise for delineating important etio-pathogenic aspects of destructive periodontal disease.     

Influence of masticatory hypofunction on the alveolar bone and the molar periodontal ligament space in the rat maxilla

Previous studies have established that complete absence of masticatory function results in a narrower alveolar process and periodontal ligament (PDL). The aim of our study was to investigate, for the first time, both the alveolar process and the PDL in masticatory hypofunction. Twenty‐six rats, 3 wk of age, were randomly assigned to either a hard‐ or a soft‐diet group (n = 13 each group). The rats were killed after 6 wk and their skulls were scanned using micro‐computed tomography (micro‐CT). We measured the cross‐sectional width of the space occupied by the PDL, as well as the cross‐sectional alveolar socket surface (AS) and the cross‐sectional root surface (RS). We also measured the width of the alveolar process. The alveolar process was narrower, the PDL width was thinner, and the AS was smaller in rats fed a soft diet compared with rats fed a hard diet. The PDL width was correlated to the alveolar process width and the AS. The narrower alveolar process found in rats fed a soft diet is the result of alterations to both the alveolar bone and the PDL. The correlation between them provides evidence that a reduction of occlusal loading induces a simultaneous response in both tissues.     

Involvement of toll‐like receptor 4 in alveolar bone loss and glucose homeostasis in experimental periodontitis

Watanabe K, Iizuka T, Adeleke A, Pham L, Shlimon AE, Yasin M, Horvath P, Unterman TG. Involvement of toll‐like receptor 4 in alveolar bone loss and glucose homeostasis in experimental periodontitis. J Periodont Res 2011; 46: 21–30. © 2010 John Wiley & Sons A/S Background and Objective: There is general agreement that certain fatty acids and lipopolysaccharides (LPS) promote inflammation through toll‐like receptor 4 (TLR4), and that inflammation promotes insulin resistance. We therefore hypothesized that mice with periodontitis and a TLR4 loss‐of‐function (LOF) mutation fed a high‐fat (HF) diet would develop improved glucose homeostasis compared with wild‐type (WT) animals with periodontitis fed a HF diet. Material and Methods: Wild‐type and TLR4 mutant mice fed a HF diet were divided into four groups (n = 6/group): WT; WT with periodontitis (WT/P); mutant (Mut); and mutant with periodontitis (Mut/P). Periodontitis was induced by placing LPS soaked ligatures around maxillary second molars. Fasting insulin and glucose levels were measured weekly for 10 wk. Glucose tolerance was evaluated at baseline (week 1) and at 9 wk. Insulin signaling (phosphorylation of Akt) and tumor necrosis factor‐α (TNF‐α) mRNA levels in liver were determined when the mice were killed at week 10. Results: Mut/P mice developed less alveolar bone loss compared with WT/P mice (p < 0.05). Fasting glucose levels were improved after 8 wk of feeding a HF diet (weeks 9 and 10) in Mut/P mice compared with Mut, WT and WT/P mice (p < 0.05). Glucose tolerance was impaired in all groups compared with baseline (p < 0.05), except for the Mut/P group. Insulin signaling was improved (p < 0.05), and expression of TNF‐α was decreased (p < 0.05) in the liver of Mut/P mice compared with the liver of WT/P mice. Conclusion: The TLR4 LOF mutation partially protects against alveolar bone loss and improves glucose homeostasis in mice with periodontitis fed a HF diet.     

Doxycycline prevents root resorption and alveolar bone loss in rats after periodontal surgery

The effect of systemic doxycycline administration on frequency of root resorption cavities and extent of bone loss following periodontal surgery was studied in albino rats. Thirty Wistar rats with healthy gingiva were divided into four groups. Six untreated animals (Group 1) served as controls. Gingivectomy (Group 2, six rats), mucoperiosteal flap operation (Group 3, eight rats), and mucoperiosteal flap operation with doxycycline added to the drinking water (Group 4, 10 rats) were performed on the palatal aspect of maxillary left molars. After a healing period of 3 wk, the rats were killed by an overdose of sodium pentothal, and specimens of first molars were prepared for light microscopy. Root resorption was absent in normal and gingivectomized animals (Groups 1 and 2). Resorption cavities occurred in all flap-operated animals (Group 3) and in one of 10 doxycycline-treated animals (Group 4). The distance from cementoenamel junction to alveolar bone crest remained unchanged in gingivectomized (Group 2) and doxycycline-treated animals (Group 4), as compared with control specimens. In flap-operated animals (Group 3), the crestal bone level was located more apically than in doxycycline-treated rats (Group 4). This study has shown that root resorption and bone loss were associated with flap operations involving exposure of periodontal ligament and bone. Systemic doxycycline prevented both root resorption and bone loss.     

Inhibition of alveolar bone loss by matrix metalloproteinase inhibitors in experimental periodontal disease

Periodontal disease is characterized by excessive host collagenase resulting in loss of gingival and periodontal ligament collagen and adjacent alveolar bone. Intragingival endotoxin injection induces a model of periodontal disease characterized by rapid bone loss with biochemical features similar to that of naturally occurring adult periodontitis. CH1766, a peptide with a zinc binding moeity which fits into the active site of the enzyme, and CH6631, a hydroxamic acid derivative with aryl-substituted sulphonamide residues, are inhibitors of matrix metalloproteinases (MMPIs) with differing inhibitory profiles as characterized by in vitro assays. In this study, endotoxin was injected into the gingivae of rats which were then treated orally with either 3 mg/kg or 30 mg/kg of one of the two inhibitory compounds. The gingival tissues were assessed for collagenase and gelatinase activity, plus three different pro-inflammatory cytokines. In addition, alveolar bone height in defleshed jaws was studied by computerized morphometric analysis and scanning electron microscopy. Both drugs reduced active and/or total MMP activity, in many cases to normal, and also partially normalized cytokine levels as well. A dose-response effect was seen with regard to amelioration of lipopolysaccharide-induced alveolar bone loss with both drugs. Other than studies with tetracyclines, this is the first report of beneficial effects of MMPIs in a model of periodontal disease, strongly suggesting that this class of agents could bring therapeutic benefit to patients with this disorder, and that periodontal disease can be used as a model to demonstrate in vivo efficacy of this class of drugs.     

糖尿病大鼠牙槽骨骨密度与全身骨密度变化的相关实验研究

目的比较雌、雄性糖尿病大鼠牙槽骨骨密度的改变以及雄性糖尿病大鼠全身骨密度的改变。方法将40只Wistar大鼠分为糖尿病组（雌、雄性大鼠各15只）和对照组（雌、雄性大鼠各5只）。腹腔注射链脲佐菌素（STZ）制备糖尿病大鼠模型,检测糖尿病组和对照组大鼠血糖、血清胰岛素和骨代谢指标,检测下颌牙槽骨、股骨和腰椎的骨密度。结果对照组和糖尿病组雄性大鼠下颌牙槽骨骨密度均高于雌性大鼠（P<0.05）;糖尿病组雌、雄性大鼠下颌牙槽骨骨密度分别低于对照组雌、雄性大鼠（P<0.05）。对照组雄性大鼠的骨密度由高至低依次为股骨、下颌牙槽骨、腰椎;糖尿病组雄性大鼠的骨密度由高至低依次为下颌牙槽骨、股骨、腰椎。结论糖尿病雌、雄性大鼠下颌牙槽骨发生了糖尿病性骨质疏松,且雌性大鼠骨质疏松更严重;雄性糖尿病大鼠下颌牙槽骨、股骨和腰椎骨密度较对照组低,下颌牙槽骨骨密度变化与股骨和腰椎的变化相一致,或是糖尿病组大鼠下颌牙槽骨骨密度变化滞后于股骨和腰椎骨密度的变化。