龈下优势菌在金合金、镍铬合金与纯钛表面黏附的实验观察

目的研究龈下优势菌在种植钛与冠修复材料表面的黏附特征。方法将烤瓷冠修复的两种基底冠材料（金铂合金、镍铬合金）分别粘接在种植纯钛板上，与四种龈下优势菌：伴放线放线杆菌（Aa），牙龈卟啉单胞菌（Pg），具核梭杆菌（Fn），中间普氏菌（Pi）共同厌氧孵育，采用菌落形成单位计数法（CFU）量化测定培养试件表面的细菌黏附量；扫描电镜（SME）观察试件表面细菌黏附的情况。结果四种龈下优势菌在金铂合金-钛试件表面细菌黏附量明显多余镍铬合金-钛试件。结论四种龈下优势菌单独附着能力有差异，Aa〉Fn〉Pg〉Pi。金铂合金的组织相容性优于镍铬合金。     

冠修复材料对龈下优势菌生长的影响

冠修复是牙体缺损后临床常用方法,修复时会造成龈沟内微生态平衡的破坏。修复后微生物的生长是恢复生态平衡、维护牙周组织健康的前提条件,环境因素的改变直接影响微生物的生长,材料的某些成份可成为激活细菌成为条件致病菌的潜在因素,微生物比例的改变使条件致病菌致病成为可能,影响牙周组织的健康,导致修复失败。本研究拟从微观上尝试评价冠修复材料的组成、性能对细菌生长的影响。研究结果认为:不同材料对不同细菌生长影响不同。Plat铸造陶瓷,Vita烤瓷,冠用湿热固化塑料对粘性放线菌、具核梭杆菌、黄褐二氧化碳噬纤维菌的生长无影响,对血链球菌的生长,四种材料均有抑制作用,以SDA-Ⅱ中熔合金的抑制作用最强,Plat铸造陶瓷最弱。细菌的生长量与培养时间以及培养液中的营养条件有关,培养时间与培养液中的营养量呈负相关关系。     

不同粗糙度金铂合金和镍铬合金对种植体龈下优势菌粘附性的影响

目的 研究不同粗糙度冠修复材料对种植体龈下优势菌粘附性的影响。方法 选用两种常用冠修复合金材料:金铂合金和镍铬合金。将其制成两种不同粗糙度的试件粘固于种植纯钛板上,分别与4种龈下优势菌牙龈卟啉单胞菌(Porphyromanus gingivalis,Pg)、伴放线放线杆菌(Actinobacillus actinomycetemcomitans,Aa)、中间普氏菌(Prevotella intermedia,Pi)及具核梭杆菌(Fusobacterium nuclertum,Fn)共同厌氧孵育,采用菌落形成单位(colony-forming unit,CFU)计数法量化测定培养试件表面的细菌量,并进行统计学分析。同时扫描电镜观察各种菌在试件上的附着情况。结果 经两两比较,同种合金中粗糙度大的试件四种细菌附着量均大于粗糙度小的(P<0.01);同种粗糙度的试件,金铂合金与种植体钛上各种细菌粘附量均大于镍铬合金与种植钛上的附着量(P<0.01)。结论 在相同条件下,冠修复合金抛光度越高,细菌粘附量越小。体外培养镍铬合金上四种细菌的粘附均小于金铂合金。     

牙预备体表面经极固宁TM处理后对全冠固位力的影响

临床上行冠、桥修复时部分活髓牙会出现牙本质过敏症状,牙体制备后或粘固冠桥前应用极固宁TM处理牙本质表面,被认为是一种有效安全、作用持久、使用简单的处理方法。本研究旨在通过体外实验来评价极固宁TM处理牙预备体表面后对玻璃离子水门汀粘固的全冠固位力的影响。1材料与方     

白色念珠菌对4种软衬材料表面黏附的比较研究

目的：比较研究白色念珠菌在不同软衬材料表面黏附情况及材料表面粗糙度对黏附量的影响。方法：将4种软衬材料制备成粗糙度不同标准试样，用白色念珠菌菌株（ATCC10261）菌液对各试样黏附后脱菌、稀释、培养计数来分析白色念珠菌对试件表面黏附。结果：4种软衬材料表面的白色念珠菌黏附量有差异，对制备成不同的粗糙度同一材料表面，白色念珠菌黏附量亦有差异，均有统计学意义。结论：软衬材料本身性能及表面粗糙度对白色念珠菌的黏附均有影响。     

两种冠修复贵金属合金与种植钛对龈下优势菌黏附的影响

目的:研究龈下优势菌在2种冠修复材料(金铂合金与金钯合金)与种植钛材料表面的黏附特征。方法:将金铂合金与金钯合金分别粘结在种植纯钛板上,与4种龈下优势菌:牙龈卟啉单胞菌(Pg),伴放线放线杆菌(Aa),中间普氏菌(Pi),具核梭杆菌(Fn)共同厌氧孵育。采用菌落形成单位(CFU)计数法量化测定培养试件表面的细菌黏附量,扫描电镜观察试件表面细菌黏附的情况。结果:Aa在2组试件上的黏附量最多,其次为Fn、Pg,最少的为Pi;龈下优势菌在金铂合金-钛试件表面细菌黏附量明显多于金钯合金-钛试件。结论:①4种龈下优势菌对同一合金试件的附着能力有差异:Aa>Fn>Pg>Pi。②金钯合金对细菌的生长与黏附有抑制作用。     

义齿软衬材料表面微生物粘附的实验室观察

目的比较研究口腔微生物在树脂类软衬材料和硅橡胶类软衬材料表面的粘附情况和材料表面粗糙度对微生物粘附的影响。方法将树脂类软衬材料和硅橡胶类软衬材料制备成不同粗糙度的标准试件,以硬质基托树脂为对照组;变形链球菌、粘性放线菌和白色念珠菌在试件表面粘附后脱菌、稀释、培养计数,分析3种菌在试件表面的粘附量。结果两种软衬材料的变形链球菌和白色念珠菌粘附量均大于硬质基托树脂,差异有统计学意义（P〈0．05）,硅橡胶类软衬材料的变形链球菌和白色念珠菌粘附量大于树脂类软衬材料,差异有统计学意义（P〈0．05）,不同粗糙度的同一种材料表面3种菌粘附量也有差异。结论软衬材料比硬质基托树脂更易粘附变形链球菌和白色念珠菌,硅橡胶类软衬材料比树脂类软衬材料更易粘附变形链球菌和白色念珠菌,表面粗糙度对口腔微生物的粘附有一定的影响。     

Luxatemp临时冠桥材料的临床应用效果研究

目的研究Luxatemp临时冠桥材料的临床应用效果。方法169例312颗需行烤瓷冠桥修复的活髓牙,用Luxatemp临时冠桥材料制作临时冠桥,从临时冠边缘适合性、解剖形态、颜色、表面光滑度4个方面评价临床效果。结果临时冠边缘适合性、解剖形态、颜色、表面光滑度的满意度分别为97.76%、100.00%、95.19%、88.78%。结论Luxatemp临时冠桥材料制作临时冠桥美观、方便,对牙髓刺激小,适合临床应用。     

唾液获得性膜对不同桥体材料表面自由能的影响

目的：评价唾液获得性膜对不同桥体材料表面自由能的影响。方法：采用接触角测量仪检测4种桥体材料(Co—Cr合金、Au—Pt合金、纯Ti以及Vita95瓷)表面形成唾液获得性膜前后试件的接触角并计算表面能。结果：制备唾液获得性膜后所有受测材料的表面自由能极性分量升高，自由能总量趋于一致。结论：唾液获得性膜会改变修复材料的表面属性，使不同材料表面自由能之间的差异减小。     

口腔修复材料界面对菌斑生物膜的影响

随着口腔医学的发展,各种口腔修复材料被广泛应用于临床治疗中。修复材料不同的表面结构及化学性质会对细菌的黏附定植以及生物膜的发育成熟产生一定的影响。在唾液环境中,虽然获得性膜可在一定程度上弱化不同材料界面的固有特性,但材料界面的某些特性仍能通过远程作用力穿透获得性膜并作用于微生物的初始黏附,从而影响生物膜的发生发展。在生物黏附早期,材料界面主要通过各种力学因素从而对微生物黏附产生影响。此外,修复材料还可通过化学物质的释放来影响生物膜的代谢。复合树脂、玻璃离子黏固剂、陶瓷材料和金属材料是口腔常见的修复材料,探讨常见口腔材料界面对生物膜的影响机制,可为口腔材料的改性研发提供理论支持。     

牙体缺损达龈下的修复初探———附43例报告

对４３例牙体缺损达龈下的病例采用牙龈，牙周和牙体联合治疗，随访２年，取得满意疗效，龋病或牙折裂致牙体缺损达龈下时，牙齿应先行牙髓治疗，采用临床牙冠延长术重建牙周考物宽度，防止牙周组织病变，利用牙髓腔和根管形态的不规则性和倒凹固位的银汞核钉可修复牙体形态，操作简单，经济实惠     

完全性斜折牙修复的临床疗效分析

目的：探讨3种完全性斜折裂牙修复的最佳治疗方式。方法：对128例龈上冠折、齐龈冠折、龈下冠根折患牙,视牙体缺损分别行全冠、铸造桩核冠、预成桩核冠修复,观察3种折裂类型的修复效果。结果：龈上冠折修复成功率为96．7％,齐龈冠折成功率为90．5％,龈下冠根折为69．6％。对于龈下冠根折,用预成桩树脂核成功率为84．6％,铸造桩核成功率为57．1％。结论：龈上冠折和齐龈冠折修复效果优于龈下冠根折,对龈下冠根折用预成桩树脂核比铸造桩核成功率要高。全冠修复完全性斜折裂牙是保存牙齿的有效方法。     

Microscopic evaluation of root surface associations in vivo

These preliminary studies were undertaken to test the effectiveness of a new procedure for in vivo examination of interactions between bacteria and root surfaces. For this purpose, four patients with juvenile periodontitis, four with chronic periodontitis, and four normal subjects were selected. For this procedure, root segments 8 mm long, 2 mm wide, and 150–200 μm thick were prepared from normal teeth extracted for orthodontic reasons. These root segments were then sterilized with ethylene oxide. In each subject, one root segment was placed in direct apposition to the mesial surface of a previously scaled lower first molar and positioned to extend 4–5 mm supragingivally and 2–4 mm subgingivally. Root strips were removed after seven days, fixed, dehydrated, and embedded in Spurr's resin. Light and electron microscopic examination of sections from the supragingival portion of root segments revealed bacteria within the root surface in all normal and chronic periodontitis subjects and in two juvenile periodontitis subjects. A nonpenetrating flora was associated with the supragingival portion of the root segments from the other two juvenile periodontitis subjects. Subgingivally, root segments from normal subjects were colonized by junctional epithelium with hemidesmosomes and wide intercellular spaces in which bacteria and polymorphonuclear leukocytes were occasionally seen. In root segments from chronic periodontitis patients, the surface appeared to be occupied by Gram (+) bacteria that were morphologically similar to those seen supragingivally in samples from the same patients. Polymorphonuclear leukocytes and a sparse, loosely associated flora was present on the surface of the subgingival portion of the root samples from juvenile periodontitis patients. The contrast between the presence of bacteria within the supragingival and subgingival portions of root segments obtained from chronic periodontitis patients and the absence of bacteria in root segments from all subgingival samples and two supragingival root samples in the juvenile periodontitis group was considered the most provocative result of the study. It was concluded, on the basis of these results, that the procedure used for the preparation and placement of root segments overcomes limitations inherent in other techniques for the study of subgingival events and permits clear discrimination between patterns of bacterial colonization of the root surface in different subject populations.     

人中性粒细胞防御素对龈下微生物的影响

对１８例中，、重度成年型牙周病患者的４０颗患牙，在牙周探诊５ｍｍ以上的牙周袋内放置民御素药线一根（含人中性粒细胞防御素８μｇ），４ｄ后取出，实验为期１１ｄ，观察用药前后龈下微生物及指标的变化。结果表明，防御素在牙周袋内保持３ｄ一，牙龈指数及出血指数明显改善，龈下菌斑的菌细胞密度降低；同时，球菌的相地比例升高，螺旋体和杆菌打对比例降低（Ｐ〈０．０５），并能维持到实验结束，本实验结果提示防御素在牙周袋     

Studies on plaque formed on implants

In vivo plaque formation on implant materials was studied. When different implant materials were set on the gingiva, the number of adhering viable bacteria depended on material surface properties 4 hours after setting, but not 48 hours after setting. The formation of pellicle-like thin layers and subsequent covering by lamellarly formed plaque were observed on the surfaces of all materials. Streptococcus species were predominant at the 4-hour setting time but anaerobes increased at the 48-hour setting time; this was common to all materials. The results indicate that surface properties of the implants influence early bacterial adherence, but do not influence bacterial flora or plaque maturation. The subgingival microflora at the neck of implants with clinically normal peri-implant tissues was compared with that at the neck of natural teeth. The bacterial isolates were classified based on their biochemical characteristics. For the spirochaetes, the number was counted directly under light microscopic observation. The most predominant bacterial species was Streptococcus, followed by Actinomyces, Neisseria and then Capnocytophaga at both sites. The ratio of spirochaetes in the microflora was extremely low for both the implant and natural tooth. Such a bacterial distribution pattern closely resembled the hitherto-reported distribution of bacteria existing in a healthy gingival crevicular. This suggested that the microflora in plaque at the neck of a normal implant is basically similar to that at the neck of a natural tooth. In conclusion, plaque formation on implant materials was not influenced by their surface properties in actual oral cavity.     

Analysis of early biofilm formation on oral implants in man

Biofilm formation on oral implants can cause inflammation of peri-implant tissues, which endangers the long-term success of osseointegrated implants. It has been reported previously that implants revealing signs of peri-implantitis contain subgingival microbiota similar to those of natural teeth with periodontitis. The purpose of the first part of this study was an atraumatic, quantitative investigation of biofilm formation on oral implant abutments; the objective of the second part was to investigate whether Haemophilus actinomycetemcomitans and Porphyromonas gingivalis were present in the crevicular fluid around oral implants. Biofilm formation on 14 healing abutments, inserted for 14 days in 10 patients, was analysed quantitatively by use of secondary-electron and Rutherford-backscattering-detection methods. A 16S rRNA-based polymerase chain reaction detection method was used to detect the presence of H. actinomycetemcomitans and P. gingivalis in the crevicular fluid. For this investigation, samples of sulcus fluid were collected with sterile paper points at four measurement points per abutment. The difference between biofilm coverage of supragingival surfaces (17.5 +/- 18.3%) and subgingival surfaces (0.8 +/- 1.0%) was statistically significant (P < 0.05). By use of universal primers, bacteria were found in all the samples taken, although the two periodontal pathogens were not found in any of the samples. The absence of periodontal pathogens from the sulcus fluid during initial bacterial colonization, despite massive supragingival biofilm formation, substantiates the assumption that cellular adherence of peri-implant tissue by means of hemidesmosoma, actin filaments and microvilli reduces the risk of formation of anaerobic subgingival pockets.     

The effects of salivas on occlusal forces

Contacting surfaces of opposing teeth produce friction that, when altered, changes the contact force direction and/or magnitude. As friction can be influenced by several factors, including lubrication and the contacting materials, the aim of this study was to measure the occlusal load alterations experienced by teeth with the introduction of different salivas and dental restorative materials. Pairs of molar teeth were set into occlusion with a weighted maxillary tooth mounted onto a vertical sliding assembly and the mandibular tooth supported by a load cell. The load components on the mandibular tooth were measured with three opposing pairs of dental restorative materials (plastic denture, all‐ceramic and stainless steel), four (human and three artificial) salivas and 16 occlusal configurations. All lateral force component measurements were significantly different (P < 0·0001) from the dry (control) surface regardless of the crown material or occlusal configuration, while the effects of the artificial salivas compared to each other and to human saliva depended on the crown material.     

Early formation of Streptococcus sobrinus biofilm on various dental restorative materials.

OBJECTIVES: To examine the formation of dental biofilm by Streptococcus sobrinus on different types of restorative materials, using a model consisting of host and bacterial constituents. METHODS: The adsorption pattern of saliva to the restorative material was determined by means of gel electrophoresis coupled with computerized densitometry techniques. The amount of salivary proteins adsorbed onto the surfaces was measured using the Bradford method. Sucrose-dependent bacterial adhesion to the saliva-coated restorative material was tested by radioactive-labelled Streptococcus sobrinus, and viable counts of these bacteria in the biofilm was determined using bacterial culture techniques. RESULTS: Different adsorption patterns by salivary proteins to restorative materials were recorded. Durafil and acrylic dental materials demonstrated the most affinity to salivary proteins. A surface dependent adhesion profile was recorded, showing a high affinity of albumin and amylase to Acrylic and Durafil materials. Bacterial accumulation was the highest with Fuji LC and Fuji GC, which also demonstrated the highest bacterial viability. CONCLUSIONS: Our study demonstrates the specificity of biofilm formation on different brands of dental restorative materials. Formation of a variety of dental biofilms has a significant impact on the progression of dental diseases in the oral cavity.     

氟化钠对5种常见龈下细菌抑制作用的体外研究

采用试管二倍液体稀释法，测定氟化钠在体外厌氧环境对雅 龈卟啉单胞菌，伴放线放线杆菌，中间型普氏菌，血链球菌和亲缘链球菌的最小抑菌浓度，比较氟化钠对上述细菌的抗菌作用。结果显示：氟化钠对各实验细菌细菌都有抑制作用，对牙周主要强疑致病菌牙龈卟啉单胞菌，伴放线放线杆菌，中间型普氏菌和龋相关菌关缘链球菌有较明显的抑制作用，ＭＩＣ值为１２８－１０２４μｇ／ｍｌ，而对牙周有益菌血链球菌则需高浓度才有抑制作用，