口腔微生物与免疫学

壳聚糖体外抑菌实验研究;伴放线放线杆菌血清型分析;母子口腔中变形链球菌基因型的对照研究;青春期龈炎龈下菌斑中牙龈卟啉单胞菌的牙龈蛋白酶K的表达；含银无机抗菌剂加入树脂中对口腔常见细菌黏附影响的研究;     

载银纳米二氧化钛树脂基托对变异链球菌和白色假丝酵母菌抗菌性的体外研究

目的采用体外法研究载银纳米二氧化钛（Ag-TiO2）树脂基托对口腔常见条件致病菌的单一游离菌体及菌斑生物膜的抗菌性能。方法将不同质量分数的Ag-TiO2抗菌粉剂添加到树脂基托材料中,制成抗菌树脂基托。采用薄膜密贴法分别检测该抗菌树脂基托对变异链球菌、白色假丝酵母菌、金黄色葡萄球菌的抗菌率,并用扫描电镜观察抗菌树脂基托表面变异链球菌、白色假丝酵母菌的生长情况。结果与未添加抗菌剂相比,抗菌剂质量分数为0.7%时,抗菌树脂基托对金黄色葡萄球菌的抗菌率达93.3%;抗菌剂质量分数为1.5%时,抗菌树脂基托对变异链球菌的抗菌率达90.2%;抗菌剂质量分数为2.5%时,抗菌树脂基托对白色假丝酵母菌的抗菌率也达91.2%。与未添加抗菌剂相比,抗菌树脂基托表面变异链球菌、白色假丝酵母菌的黏附数量明显减少。结论Ag-TiO2可以显著提高树脂基托的抗菌性能。     

牙科树脂中添加无机抗菌剂的研究进展

牙科树脂材料,包括义齿基托树脂和复合树脂等,广泛地应用于口腔修复科和口腔内科治疗。由于口腔是个有菌环境,树脂上容易黏附和聚集细菌,形成菌斑,导致黏膜炎或龋病等疾病。添加无机抗菌剂赋予树脂抗菌性能,可以减少细菌在其上的黏附、聚集和繁殖。本文就研究较多的纳米载银、纳米二氧化钛、氧化锌这三类无机抗菌剂在牙科树脂中的进展作一综述。     

Ag-TiO2树脂基托抗菌性及长效性的体外研究

目的:研究纳米Ag-TiO2树脂基托对口腔2种常见致病菌的抗菌性及抗菌长效性。方法:将2.5%(w/w)的纳米Ag-TiO2抗菌剂添加到热凝型树脂基托中,再对其分别进行自然老化和加速老化处理。采用薄膜密贴法分别检测老化处理组和新制备的抗菌基托组对变异链球菌、白色念珠菌单一菌种的抗菌性;并用扫描电镜(SEM)观察抗菌基托表面变异链球菌菌斑生物膜的粘附生长情况。结果:与未添加抗菌剂的树脂基托相比,新制备的抗菌基托对变异链球菌、白色念珠菌的抗菌率分别为98.1%、90.3%;自然老化组的为97.1%、89.4%;加速老化组的为96.3%、88.7%,3组抗菌基托的抗菌率之间无显著差异性;扫描电镜(SEM)可见抗菌基托表面粘附的变异链球菌数量明显减少。结论:纳米Ag-TiO2抗菌树脂基托抗菌性能良好,且抑制细菌、真菌作用长久。     

纳米载银树脂基托的体外抗菌效果

目的研究纳米载银树脂基托在体外对变形链球菌和白色念珠菌的抗菌效果。方法先测定纳米载银抗菌剂对变形链球菌和白色念珠菌的最小抑菌浓度,并以此为依据在聚甲基丙烯酸甲酯基托树脂粉中添加不同比例的抗菌剂,制成抗菌树脂基托,用贴膜法测定该树脂基托对变形链球菌和白色念珠菌的抗菌率。结果纳米载银抗菌剂对变形链球菌的最小抑菌浓度为0.1mg/ml,对白色念珠菌的最小抑菌浓度为1mg/ml。当添加抗菌剂的浓度分别为1、2、5、10mg/ml时,树脂基托对变形链球菌的抗菌率分别为67.4%、71.3%、99.0%、99.5%;对白色念珠菌的抗菌率分别为25.8%、54.8%、90.3%、93.0%。结论载银抗菌树脂基托在体外表现了一定的抗变形链球菌和抗白色念珠菌的效果,当树脂基托中抗菌剂的浓度达到5mg/ml时,抗菌效果满意。     

两种纳米无机抗菌剂在基托树脂中的抗菌应用研究

由于配戴聚甲基丙烯酸甲酯制作的可摘局部义齿或全口义齿常诱发义齿接触部位龋病、义齿性口炎等并发症,近年来许多学者尝试将不同类型的抗菌剂加入到义齿基托树脂中,进行一系列体外实验,以期提高其抗菌性能,降低基托接触部位并发症的发生。其中,纳米载银抗菌剂和纳米二氧化钛（TiO2）抗菌剂是研究最为广泛的两种无机抗菌剂。本文就这两种抗菌剂的抗菌机理,抗菌效果,细胞毒性,加入抗菌剂后基托树脂的机械性能等方面进行综述。     

义齿基托材料清洁抗菌研究新进展

聚甲基丙烯酸甲酯是临床上最常用的义齿基托材料。义齿戴入口腔后,基托表面会有菌斑或牙石沉积,对口腔组织产生各种不良影响。采用基托表面处理及向基托中添加抗菌剂来提高基托自身抗菌性能是近年来的研究热点,本文从这两方面对近年来义齿基托清洁抗菌的新研究成果进行综述。     

抗菌钛合金在口腔医学中应用研究进展

广泛应用于口腔医学领域的钛合金,由于长期处于复杂微生物环境中,材料表面易形成细菌生物膜,影响其使用效率和寿命。抗菌钛合金是一种通过表面改性或整体改性的方法添加了抗菌剂的新型钛合金。根据抗菌剂在钛合金材料中分布的位置,抗菌钛合金分为涂层型和合金型。涂层型抗菌钛合金的抗菌效果良好,但缺点是涂层大多不耐磨;合金型抗菌钛合金的抗菌剂一般为金属元素,可在合金中均匀分布,抗菌性能稳定持久。根据抗菌钛合金能否释放抗菌剂,分为主动抗菌型和被动抗菌型,主动抗菌型钛合金可释放负载的抗菌剂,抗菌效果比较明显,但有些抗菌剂的释放时间较短;被动抗菌型钛合金不释放抗菌剂,通过接触杀菌或抑制细菌黏附的方式产生抗菌作用。抗菌钛合金可抑制材料表面细菌黏附,对延长矫治器、种植体、钛板等在口腔内的使用寿命具有重要意义,且抗菌改性后钛合金的机械性能未受明显影响,羟基磷灰石等抗菌剂的加入还提高了材料的成骨功能,在种植义齿、正畸矫治及口腔颌面外科等口腔医学领域应用前景良好。但是,目前关于抗菌钛合金的研究大多是体外实验,其长期的临床效果及其抗菌机制仍不明确,有待深入研究。     

纳米载银无机抗菌剂在树脂基托中应用的研究进展

近年来，载银纳米无机抗菌剂在医学生物领域得到了广泛应用，本文介绍载银纳米无机抗菌剂在树脂基托中应用的研究进展，分析其在树脂基托中的抗菌作用、生物安全性及对基托性能、颜色的影响。     

丙烯酸酯类义齿基托材料的研究进展

本文介绍了使用新型热聚合器、树脂上光剂、化学清洁剂改善热固化型丙烯酸酯类义齿基托表面光洁度和在基托材料中加入抑菌剂以减少基托表面细菌粘附的方法。在基托中加入玻璃纤维、超高分子量聚乙烯纤维等提高基托机械强度的材料研究新进展。     

Inhibitory effect of antibacterial resin composite against Streptococcus mutans.

Dental resin composites with antibacterial activity may be useful for preventing the secondary caries frequently seen around restorations. Three types of silver-supported antibacterial materials (Novaron, Amenitop and AIS) inhibited the growth of the major oral pathogen Streptococcus mutans. Minimum inhibitory amounts in suspensions of Novaron, Amenitop and AIS against S. mutans were 40, 30 and 400 microg/ml, respectively. These antibacterial materials were incorporated into TEGDMA-UDMA-based light-activated resin composite, and the antibacterial activities of these composites were examined. Composites incorporating 5 wt% (N-5) or more of Novaron and 7 wt% (AM-7) or more of Amenitop inhibited the growth of S. mutans, whereas composites incorporating up to 10 wt% of AIS did not. No significant difference in either compressive or flexural strength was observed between the control and N-5 composites after 1 day and 6 months of storage in water. However, for AM-5 composite, there was a significant difference in either strength parameter between the two immersion periods. There was no or extremely little release of silver ions from the N-5 and AM-5 composites after 1 day or 6 months of immersion in water. These results indicated that a light-activated resin composite incorporating silver-supported antibacterial material such as Novaron may be clinically useful due to its inhibitory effect against S. mutans and favorable mechanical properties.     

Hinokitiol Inhibits Candida albicans Adherence to Oral Epithelial Cells

Candida spp. are an opportunistic pathogen causing serious local and systemic infections, especially in immuno-compromised hosts such as the elderly and HIV-positive patients. Hinokitiol C₁₀H₁₂O₂ (β-thujaplicin) is a component of the essential oils isolated from Cupressaceae and shows antibacterial activities for various bacteria. The aim of this study was to demonstrate the preventive effects of hinokitiol on the adherence of seven species of Candida to oral epithelial cells and to establish a safe and useful method for oral hygiene. A short-time treatment (30 min) with 0.25 mM hinokitiol showed 30–70% inhibition of adherence of Candida spp. to oral epithelial cells, inhibited about 11% biofilm formation, and did not inhibit the cell growth of Candida spp. Furthermore, short treatment with 0.25 mM hinokitiol was a safe method for oral hygiene against Candida infection because it did not inhibit the cell growth of commensal bacteria, such as oral streptococci existing in normal flora, or damage the epithelial cells. However, long-time treatment and a high concentration of hinokitiol demonstrated both the adherence inhibition of Candida and damage to commensal bacteria and epithelial cells. Our data suggest an appropriate procedure to apply hinokitiol that may be beneficial for the prevention of opportunistic pathogens such as Candida spp. in the oral cavity. The clinical and daily use of hinokitiol under an appropriate procedure may be a preventive and realistic therapy for Candida infection in immune-compromised hosts.     

纳米载银室温固化PMMA材料对雄性小鼠生殖系统的影响

目的:研究添加2%浓度纳米载银无机抗菌剂的室温固化型聚甲基丙烯酸甲酯(PMMA)材料对雄性小鼠生殖系统的影响。方法:将雄性昆明小鼠随机分组,动物实验模型建立完成后,处死。计算小鼠体重增长率、睾丸脏器系数,观察睾丸组织的病理学改变,进行精子活动率检测、计数和畸形率计算。采用初级精母细胞染色体畸变实验和精原细胞姊妹染色单体互换(SCE)实验检测实验材料对小鼠初级精母细胞及精原细胞染色体的影响。结果:添加2%浓度纳米载银室温固化PMMA材料对小鼠体重增长率、睾丸脏器系数以及精子计数、活动率和畸形率均无显著性影响,各实验组睾丸组织病理切片与阴性对照组无明显差异。添加2%浓度纳米载银室温固化PMMA材料对小鼠的初级精母细胞染色体无致畸变作用;各实验组精原细胞SCE率与阴性组无显著性差异。结论:添加2%浓度纳米载银室温固化PMMA材料对雄性小鼠生殖系统无显著影响。     

纳米载银无机抗菌剂与义齿清洁剂对室温固化PMMA材料抗菌性能及力学性能的影响

目的：研究不同抗菌方式对室温固化聚甲基丙烯酸甲酯（PMMA）材料表面上的白色念珠菌的抗菌效果,并比较不同抗菌方式对室温固化PMMA材料弯曲强度的影响。方法：运用贴膜法,检测添加2％浓度纳米载银无机抗菌剂的室温固化PMMMA试件与经4种常用的义齿清洁剂（保丽净、雅克菱、澳多-C、Protefix）浸泡的普通室温固化PMMA试件和单一机械刷洗处理对白色念珠菌的抗菌率。按照上述方式处理,模拟口腔环境对试件进行14d的加速老化处理,在万能材料试验机上对试件进行弯曲强度测试。结果：抗菌剂含量为2％时,对白色念珠菌的抗菌率达到90％以上。4种义齿清洁剂的抗菌率均超过50％,保利净的抗菌率超过90％,与添加2％抗菌剂的抗菌率无显著性差异。机械刷洗方法抗菌率达到70％。在老化条件下,机械处理的试件弯曲强度显著降低（P〈0．05）。结论：添加2％浓度纳米载银无机抗菌剂和保利净义齿清洁剂抗菌效果最佳。长时间应用机械刷洗的方法会对室温固化PMMA的弯曲强度产生显著影响。     

Addition of antibacterial agents to MMA-TBB dentin bonding systems--influence on tensile bond strength and antibacterial effect

To produce a bonding system which has both high bond strength and antibacterial properties, an antibacterial agent (vancomycin: VCM or metronidazol: MN) was added to the PMMA powder of 4-META/MMA-TBB resin (CB). The influence of the addition of an antibacterial agent on tensile bond strength to dentin and the antibacterial effect were investigated in this study. Forty-seven freshly extracted bovine first or second incisors were used to measure the tensile bond strength to dentin. The bond strengths to bovine dentin were not significantly decreased by addition of VCM (1%, 2%, 5%), or MN (1%) to CB (p < 0.05). The antibacterial effect of CB containing antibacterial agent on six strains of bacteria was investigated by the agar plate diffusion method, analyzing the appearance of the inhibition zone around a resin disk following anaerobic culturing. The resin disks containing VCM showed antibacterial effects on all of the strains examined; the widths of the inhibition zones were 4-15 mm. The resin disks containing MN showed antibacterial effects on three strains; the widths of the inhibition zones were 0-4 mm. It was thus possible to produce a bonding system with both antibacterial effect and high tensile bond strength by addition of VCM to PMMA powder.     

花多酚、鞣酸抗细菌生长、粘附能力的研究

目的：探讨茶多酚、鞣酸对致龋菌生长、粘附能力的影响。方法：参照已有的多酚、鞣酸溶液MIC,观察不同浓度药液中变边菌Ing、6715和粘放菌ATCC19246的生长、粘附情况。结果：茶多酚对变链菌lng的生长有较强的抑制能力,而鞣酸对三种受试菌的生长均有较强抑制能力,二药对变链菌Ing、6715有轻微的抗粘附活性。,对粘放菌19246则无作用。结论：茶多酚、鞣酸具有一定的抑制细菌生长能力,并变链菌Ing、6715有轻微的抗粘附活性。     

In vitro study of antibacterial and antiadhesive activities of fluoride-containing light-cured fissure sealants and a glass ionomer liner/base against oral bacteria

The aim of this study was to estimate the antibacterial and anti-adhesive properties of light-cured pit-and-fissure sealants containing fluoride (Teethmate F-1, TF; UltraSea-1 XT, US) or not containing fluoride (Teethmate A, TA)- and glass ionomer liner/base containing fluoride (Vitrebond, VB) against oral bacteria in vivo. VB inhibited the growth of S. mutans, S. oralis and L. casei aerobically and anaerobically, and TA and US inhibited the growth of only S. mutans aerobically. The numbers of adherent cells mediated by insoluble glucan for all materials were lower than that for the control tooth. The numbers of adhesional cells not mediated by insoluble glucan were larger than that for the control tooth. VB showed the highest concentration of fluoride released throughout the four-week observation period, and had the highest pH value. In this study, VB showed superior antibacterial action and fluoride-release compared with the other three materials.     

The influence of sucralose on bacterial metabolism

Sucralose (1',4',6' trideoxy-trichloro-galactosucrose) is a nontoxic, intensely sweet sucrose derivative that has been shown to be non-cariogenic in experimental animals. The purpose of this study was to determine whether certain oral bacteria could utilize sucralose. Sucralose, as a sole carbon source, was unable to support growth of ten strains of oral bacteria and dental plaque. When sucrolose was incorporated into a liquid medium containing glucose or sucrose, all organisms tested displayed similar pH falls, compared with controls. The incorporation of 126 mmol/L sucralose into glucose agar medium caused total inhibition of growth of Streptococcus sobrinus 6715-17, Streptococcus sanguis 10904, Streptococcus sanguis Challis, Streptococcus salivarius, and Actinomyces viscosus WVU627. Sucralose had no effect on IPS production. Sucralose was not bound to, nor taken up by, cells. Sucralose inhibited the formation of glucan and fructan polymers in proportion to the sucralose-to-enzyme ratio, but independent of the sucrose concentration in the assay mixture. No radioactive polymer was formed from 14C-U-sucralose added to mixtures containing glucosyltransferase (GTF) or fructosyl-transferase (FTF). Inhibition of GTF and FTF by sucralose was removed following dialysis of the enzyme/sucralose mixture. These results show that sucralose was not utilized by the oral bacteria tested and that the inhibitory effect of sucralose on GTF and FTF was non-competitive and reversible. The results further support the concept that sucralose is non-cariogenic.     

不同种类无机抗菌剂对口腔致病菌抗菌性能比较及其检测方法探讨

目的:比较无机抗菌剂对口腔致病菌的抗菌活性,并探讨不溶物质的优选测试方法。方法:采用试管液体稀释法和琼脂稀释法测试6种无机抗菌剂对6种口腔常见致病菌的抗菌活性。结果:试管液体稀释法测试结果显著低于琼脂稀释法。受试抗菌剂体外综合抗菌活性从高到低依次为:龙贝无机抗菌粉体、ZnOw AT-83、IONPURE-H、碱式次氯酸镁、ZnOw AT-88、安迪美-AMS2。结论:6种无机抗菌剂对实验菌株均有不同程度的抗菌活性。不溶性物质抗菌活性测试宜用液体稀释法。