义齿基托修复材料表面粗糙度对变形链球菌粘附的影响

目的：观察义齿基托修复材料的表面粗糙度对变形链球菌粘附的影响,为正确处理义齿基托的表面提供参考。方法：常规制备钴铬合金标准试件8mm×8mm×1mm共40件,分为5组,每组8件,分别按照五种不同的打磨方法处理试件表面,使用手持式表面粗糙度仪测量每组试件的表面粗糙度,通过体外粘附实验观察变形链球菌在不同表面粗糙度试件上的粘附情况,进行Pearson相关性检验和单因素方差分析。结果：各组试件的表面粗糙度与变形链球菌粘附量之间有显著相关性（P〈O．01）,各组试件细菌粘附量之间的差异具有显著的统计学意义（P〈0．01）。结论：义齿基托修复材料表面粗糙度与细菌的粘附量呈正相关,提示制作义齿时应通过正确的方法减小义齿的表面粗糙度。     

变形链球菌黏附对铜铝合金、钴铬合金表面粗糙度影响的初步研究

目的研究变形链球菌黏附对铜铝合金、钴铬合金表面粗糙度的影响。方法用6JA型干涉显微镜测量金属试件的表面粗糙度,了解变形链球菌黏附铜铝合金、钴铬合金表面一段时间后,金属表面粗糙度的变化。结果钴铬合金试件空白组、实验组6周、10周3组金属试件表面粗糙度(Rz)均值总体之间差异无显著性(P>0.05)。铜铝合金试件空白组、实验组(8周)、对照组(8周)3组金属试件Rz均值总体之间差异有显著性(P<0.05),两两比较,各组间差异均有显著性(P<0.05)。结论变形链球菌黏附钴铬合金表面短时间内金属表面粗糙度无明显变化,黏附铜铝合金表面粗糙度变化明显。     

3种牙科铸造金属模拟唾液浸泡后粗糙度的变化

目的：通过考察钴铬合金、镍铬合金以及纯钛在不同pH值人工唾液中浸泡后表面粗糙度的变化，研究3种常用牙科金属的耐腐蚀能力。方法：将3种金属的标准铸造试件逐级打磨抛光后。浸泡于pH值分别为7．0和5．6的人工唾液中。3个月后检测试件表面粗糙度，并用金相显微镜观察试件表面。采用SPSS11．0软件包对数据进行单因素方差分析及t检验。结果：pH=5．6的人工唾液浸泡后，3种材料表面粗糙度有显著差异，镍铬合金〉钴铬合金〉纯钛金属（P〈0．01）。pH=7．0的人工唾液浸泡后，镍铬合金表面粗糙度大于钴铬合金和纯钛（P〈0．01），但钴铬合金和纯钛之间无统计学差异（p〉0．05）。pH=5．6人工唾液浸泡组的镍铬合金和钴铬合金表面粗糙度大于pH=7．0组的同种材料（P〈0．01）。各试验组表面粗糙度大小与显微镜观察到的材料表面腐蚀程度一致。结论：纯钛在酸性和中性环境下均有较强的耐腐蚀性，钴铬合金、镍铬合金在酸性介质中的耐腐蚀性较差。3种金属的耐腐蚀性由大到小排列为：纯钛金属〉钴铬合金〉镍铬合金。     

两种口腔致病菌对钴铬和镍铬合金的体外腐蚀行为

目的 通过体外实验，探讨白色念珠菌和变形链球菌对钴铬合金和镍铬合金耐腐蚀性能的影响。方法 将10 mm×10 mm×2 mm的钴铬合金和镍铬合金试片高度抛光后分别浸泡于实验组(A组：白色念珠菌组，B组：变形链球菌组)及对照组(C组：BHI培养液组)中8周，应用电化学法测定各组试件片的自腐蚀电流(I_corr)及极化电阻(R_p)，并利用扫描电镜观察表面形态。结果 电化学法显示钴铬合各组的I_corr依次为A组>B组>C组，R_p结果显示A组corr>钴铬合金，而R_p<钴铬合金，上述差异均具有统计学意义(P<0.05)。结论 白色念珠菌、变形链球菌对钴铬合金和镍铬合金有腐蚀作用，相同条件下钴铬合金耐腐蚀性能优于...     

支架用钴铬合金表面镀金对变异链球菌粘附的影响

目的：研究支架用钴铬合金表面镀金对变异链球菌粘附能力的影响。方法将义齿支架用钴铬合金制作成试件,随机分为实验组和对照组,每组30块。实验组表面镀金处理,对照组表面不做任何处理。用SJ-201便携式表面粗糙度仪检测两组粗糙度差异。通过细菌体外粘附实验分析4h、8h、12h时每组试件表面变异链球菌的粘附量。通过测定粘附于试件表面的变异链球菌表达CAT(报告基因产物)的活性,确定镀金处理对变异链球菌合成细胞外多糖能力的影响。结果实验组试件表面变异链球菌的粘附量均少于对照组(P<0.05);其表达CAT的能力明显低于对照组(P<0.05)。结论钴铬合金表面镀金可有效抑制变异链球菌的粘附,作用机制可能与其抑制gtfB基因表达有关。     

常用可摘局部义齿支架材料表面微生物粘附的实验研究

［摘要］ 目的 研究变异链球菌和白色念珠菌对3种口腔常用金属材料的粘附性,为临床选择合适的材料提供理论依据。方法 选取最常用做可摘局部义齿支架材料的3种金属——钴铬合金、Vitallium 2000材料、纯钛,分别制成尺寸为20 mm×10 mm×2 mm的试件,每组各6个。将各组试件抛光,并保证各组间粗糙度无明显差异。选取变异链球菌和白色念珠菌作为实验菌株,制成菌悬液,分别放入试件进行48 h的粘附实验,取出试件后冲洗、震荡、培养,采用菌落形成计数法(CFU)测定微生物表面粘附量。结果 粘附48 h后,试件表面变异链球菌和白色念珠菌的粘附数量均为钴铬合金>纯钛>Vitallium 2000材料 (P＜0.05)。结论 Vitallium 2000材料与钴铬合金和纯钛相比,粘附微生物的数量最少,值得应用推广。     

三种非贵金属合金常规研抛后的超微结构表面特征研究

目的:试验观察3种非贵金属合金经临床常规使用的机械法研抛后的超微结构表面特征,为临床合理选择材料提供实验依据,并为非贵金属改性提供合理有效的超微结构理论依据。方法:采用镍铬合金、钴铬合金、维他灵(VITALLIUM,钴铬钼合金)3种非贵金属合金作为试验对象,制成15mm×l5mm×2mm的试件,经过喷砂、橡胶轮加毡轮加抛光膏抛光机械法研抛处理后,分别在扫描电子显微镜下,观察镍铬合金、钴铬合金,维他灵的表面形貌,并在原子力显微镜下,观察3种合金的表面形貌和3D图像以及粗糙度。结果:扫描电镜、原子力显微镜结果显示3种非贵金属合金经喷砂及抛光处理后其粗糙度为喷砂组:镍铬合金(463.83±65.17)>钴铬合金(336±146.04)>维他灵2000(303±139.10);抛光组:镍铬合金(15.95±4.55)>钴铬合金(9.17±2.58)>维他灵2000(9.15±2.69)。镍铬合金>钴铬合金>维他灵。镍铬合金3D图像形貌明显、立体感强,钴铬合金较平坦,维他灵平坦。结论:SEM及AFM下,形貌平坦程度:镍铬合金<钴铬合金<维他灵,AFM与常规SEM相比,图像分辨率清晰,操作简便。     

口腔内3种合金共存下的离子析出及表面粗糙度的改变

目的：研究口腔内3种合金共存下的离子析出及表面粗糙度的改变,为临床合金修复材料的选择提供参考。方法：制作镍铬合金、钴铬合金和金银钯合金标准试件,分为镍铬合金（N组）、钴铬合金（C组）、金银钯合金（A组）、镍铬合金与金银钯合金（NA组）和镍铬合金与钴铬合金（NC组）5组。浸泡于标准电解质溶液（T=37 ℃,pH=2.31）中,每组平行重复4次。7 d后,用电感耦合等离子体质谱仪检测各组浸提液中离子析出量;用原子力显微镜观察各组试件表面形貌,测量表面粗糙度。采用SPSS 18.0软件包对数据进行统计学分析。结果：析出的镍离子量N组为（1.32±0.03） μg/cm², NA组为(2.13±0.07) μg/cm²,NC组为(1.53±0.08) μg/cm²,NA组、NC组均显著多于N组,NA组显著多于NC组（P<0.05）;析出的铬离子量N组为(0.06±0.01) μg/cm²,NA组为(0.08±0.01) μg/cm²,NC组为(0.05±0.01) μg/cm²,NA组显著多于NC组（P<0.05）。镍铬合金的表面粗糙度N组为(4.60±0.16) nm,NA组为(5.37±0.08) nm,NC组为(5.04±0.15) nm,NA组、NC组均显著大于N组,NA组显著大于NC组（P<0.05）。镍铬合金与金银钯合金或钴铬合金共存时,析出的镍离子量比其单独使用时明显增多,其表面粗糙度明显增大;镍铬合金与金银钯合金共存时比镍铬合金与钴铬合金共存时析出的镍、铬离子量多,镍铬合金的表面粗糙度也大。结论：临床上应尽量避免在患者口腔内同时应用镍铬合金与金银钯合金,或镍铬合金与钴铬合金,尽量避免贱金属的临床使用。     

纳米非晶金刚石膜镀覆对镍铬及钴铬烤瓷合金离子析出的影响

目的：观测纳米非晶金刚石膜对镍铬及钴铬两种非贵金属烤瓷合金在人工唾液中金属离子析出的影响。方法：制备镍铬合金、钴铬合金圆片形试件各24个,镍铬及钴铬合金试件随机分成a1、b1及a2、b2各两组,a1、a2组试件表面不镀膜,b1、b2组试件表面完整镀膜膜厚60nm,将a1、a2、b1、b2每组试件平分两半,分别置于pH值为6.8和4.0的人工唾液中浸泡7天,检测各组试件的金属离子析出量。结果：a1、a2组试件在两种人工唾液中表现出其所含各种金属离子的析出,在pH=4酸性人工唾液中浸泡后的离子析出量显著高于其在pH=6.8中性人工唾液中浸泡后的离子析出量（P〈0.05）;b1、b2组试件在两种人工唾液中浸泡后,其离子析出量分别比a1、a2组试件显著降低（P〈0.01）。结论：镍铬合金、钴铬合金在中性和酸性人工唾液中表现出其所含各种金属离子的析出,在酸性人工唾液中其金属离子析出量显著增加;纳米非晶金刚石镀膜能显著降低镍铬、钴铬合金在中性和酸性人工唾液中的金属离子析出量,有良好的耐腐蚀性。     

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。     

Adherence of Streptococcus mutans to various restorative materials in a continuous flow system

A continuous flow system was developed to evaluate the adhesion of Streptococcus mutans ATCC 25175 to filling materials (Ariston, Tetric, Dyract, Compoglass, Vitremer, Aqua Ionofil, Ketac Fil, amalgam, Galloy and ceramics as controls). Streptococcus mutans was added to saliva-coated test specimens, and a nutrient broth permanently supplied over a time period of 48 h and then the weight of plaque, the number and viability of the bacteria adhering to the materials were determined. The weights of artificial plaque on all filling materials tested were higher than those on ceramics, the highest values were measured on the glass-ionomers. The amount of plaque correlates with the surface roughness, whereas there was no correlation of the surface roughness with the number of colony-forming units (CFU) of S. mutans. The CFU of adhering S. mutans also depends on the viability of the bacteria. The plaque on Ketac Fil contained a high number of viable bacteria. The fluorides of glass-ionomers do not efficiently prevent the attachment and the viability of S. mutans.     

Streptococcus mutans biofilm changes surface-topography of resin composites.

OBJECTIVES: Polymerized resin composites and nonpolymerized monomers are reported to accelerate bacterial growth. Furthermore, in vivo, resin composite restorations accumulate more plaque than other restorative materials. The purpose of this study was to test the hypothesis that bacteria-composite surface interaction causes changes in surface-topography. METHODS: Resin composite disks were polymerized between two glass slides. Streptococcus mutans cells were brought in contact with and grown on the disks for 1 day, 1 week or 1 month. The disks were analyzed using atomic force microscopy. One-month-aged composite specimens were assayed for changes in micro-hardness and bacterial outgrowth. RESULTS: Atomic force microscopy analysis revealed a time-dependent increase in root mean square (RMS) roughness (p<0.0001). S. mutans outgrowth was accelerated following direct contact with the surface of aged composites, with no changes in micro-hardness. SIGNIFICANCE: Our results show that S. mutans growth on resin composite increases surface roughness without affecting micro-hardness. The change in surface integrity may further accelerate biofilm accumulation.     

The influence of 30-day-old Streptococcus mutans biofilm on the surface of esthetic restorative materials--an in vitro study

OBJECTIVE: To evaluate the effects of Streptococcus mutans biofilm/restorative materials interaction on surface roughness, hardness and morphology of materials tested. METHODS: Empress 2 (E2), Filtek Supreme (FS), Vitremer (V) and Ketac Molar Easymix (KM) were tested. Twenty-five disks of each material were made and divided into three storage groups: (1) 100% relative humidity (n=5); (2) growth medium (BHI and 1% sucrose) (n=5); (3) S. mutans biofilm-growth medium (n=15). Before storage, hardness measurements were immediately obtained from group 1 specimens. After 30 days of storage, the specimens were cleaned in order to obtain the surface roughness and hardness values, besides morphology analysis by scanning electron microscopy. RESULTS: The surface roughness and hardness values obtained from E2 and FS specimens did not present statistically significant differences among the groups 1, 2 and 3 and between immediate and 30-day-old specimens of each material. However, group 3 specimens of V and KM showed statistically significant higher surface roughness means than other groups. Group 1 specimens of V and KM also showed higher hardness values than the immediate values. Group 3 specimens of V presented decreased hardness values compared with other groups. The scanning electron micrographs showed an increase in surface degradation from group 1 to group 3 for FS, V and KM. CONCLUSIONS: Thirty-day-old biofilm promotes a negative effect on the surface morphology of FS, V and KM, on the surface roughness of V and KM and on the hardness of V.     

In vitro adherence of bacteria to bleached or unbleached enamel surfaces

summary The purpose of this in vitro study was to evaluate the effects of three 10% carbamide peroxide bleaching agents on adherence of bacteria to tooth enamel surface. Enamel specimens were subjected to one of three carbamide peroxide solutions for 8 h per day for 30 days. Control specimens were kept in saline solution. Profilometer evaluation of surface roughness was performed on all specimens. The adherence of Streptococcus mutans was determined bacteriologically. There was no significant difference in surface roughness between the untreated and treated enamel specimens but a statistically significant difference was found in the adherence of S. mutans to bleached and unbleached enamel specimens. Specimens treated with Opalescence^° showed the highest adherence.     

Biodegradation and abrasive wear of nano restorative materials

The purpose of this study was to evaluate the biomechanical degradation of two nanofilled restorative materials (a resin-modified glass ionomer, Ketac N100 and a composite, Filtek Z350), compared with conventional materials (Vitremer and TPH Spectrum). Twenty specimens obtained from each material were divided into two storage groups (n=10): relative humidity (control) and Streptococcus mutans biofilm (biodegradation). After 7 days of storage, roughness values (Ra) and micrographs by scanning electron microscopy (SEM) were obtained. In a second experimental phase, the specimens previously subjected to biodegradation were fixed to the tooth-brushing device and abraded via toothbrushes, using dentifrice slurry (mechanical degradation). Next, these specimens were washed, dried, and reassessed by roughness and SEM. The data were submitted to repeated measures three-way analysis of variance (ANOVA) and Tukey tests (p<0.05). There was statistically significant interaction among factors: material, storage (humidity/biofilm), and abrasion (before/after). After biodegradation (S mutans biofilm storage), Ketac N100 presented the highest Ra values. Concerning bio plus mechanical challenge, TPH Spectrum, Ketac N100, and Vitremer presented the undesirable roughening of their surfaces, while the nano composite Filtek Z350 exhibited the best resistance to cumulative challenges proposed. The degraded aspect after biodegradation and the exposure of fillers after mechanical degradation were visualized in micrographs. This study demonstrated that the nanotechnology incorporated in restorative materials, as in composite resin and resin-modified glass ionomer, was important for the superior resistance to biomechanical degradation.     

The influence of oral bacteria on the surfaces of resin-based dental restorative materials--an in vitro study

Three tooth-coloured, resin-based restorative materials (Charisma, Dyract, and Pertac) were exposed to typical oral bacteria (S. mutans, S. oralis and A. naeslundii) over a period of up to 35 days. The three strains of bacteria all colonised the resin-based materials within a few hours and formed thick bacterial films. Determination of the bacterial glucose consumption and lactate production during the incubation period showed no difference from the controls which contained no resin samples. Following the experimental exposure, the materials were examined by scanning electron microscopy (SEM) for possible surface damage and roughness was measured in a perthometer. Little damage to the resin-based composite material surfaces (Charisma, Pertac) could be observed, whereas the polyacid-modified composite material (Dyract) showed greater damage. There was a significant difference in the resin surface roughness after exposure to S. mutans and to A. naeslundii. The study clearly showed that the bacteria used strongly adhered to the resin-based restorative materials. As a consequence of bacterial colonisation and/or poor oral hygiene, damage to the restorative materials might develop. This suggests the need for dentists to evaluate personal oral hygiene, along with general indications and economic factors, in selecting materials for restorations, since the known anti-bacterial properties of amalgam are considerable.     

含精氨酸的抗敏抛光膏对暴露牙本质表面变异链球菌黏附的影响

目的 研究含精氨酸抗敏抛光膏对暴露牙本质表面变异链球菌黏附的影响。方法 暴露牙本质小管,使用浮石粉和抗敏抛光膏处理表面,观察其粗糙度的变化。体外培养变异链球菌,观察其在牙本质片表面黏附及葡糖基转移酶（GTFs）基因表达情况。结果 使用浮石粉及抗敏抛光膏均能有效降低表面粗糙度,抗敏抛光膏处理后的牙本质能明显抑制gtfB和gtfC基因的表达。结论 含精氨酸抗敏抛光膏能抑制变异链球菌黏附及gtfB和gtfC基因的表达,对敏感牙本质区域龋病发生具有一定防治作用。     

Effects of root dentin surface coating with all-in-one adhesive materials on biofilm adherence

OBJECTIVES: Sealing of exposed root dentinal surfaces with adhesive materials is expected to be a promising approach for preventing root dentin caries. The aim of this study was to evaluate the effects of surface coating with all-in-one adhesives on inhibiting Streptococcus mutans biofilm attachment. MATERIALS AND METHODS: Bovine root dentin was cut and ground with #600-grit SiC paper. Each of the three all-in-one adhesives, Hybrid Bond (HB), Reactmer Bond (RB) or Shake One (SO) was single-coated on the dentin surfaces according to the manufacturers' instructions. The dentin surface without coating served as the control. The surface roughness of the coated and non-coated dentin surfaces was recorded by means of laser microscope measurements. S. mutans artificial biofilms were then grown on the surface of each specimen in a microcosm for 20h. The amounts of bacteria and water insoluble glucan in the retained biofilm on the surface of the specimens were measured. All numerical data were statistically analyzed using one-way ANOVA & Tukey's HSD (p<0.05). RESULTS: All of the coated groups showed significantly lower susceptibility to biofilm attachment compared with the non-coated root dentin (p<0.05). Among the coated groups, SO showed the lowest susceptibility for biofilm formation. CONCLUSIONS: Three all-in-one adhesive materials could be effective for root surface coating. A fluoride-releasing adhesive, SO demonstrated the strongest potentiality in resisting biofilm formation.