用激光共聚显微镜研究菌斑生物膜的结构

目的：研究菌斑生物膜的结构。方法：从牙齿表面获得完整的菌斑生物膜标本,运用激光共聚焦显微镜对其进行断层扫描和分析。结果：菌斑生物膜是由分布不均匀的细胞、基质和空隙构成的复杂结构。结论：应用激光共聚焦显微镜技术研究菌斑生物结构是一种可行的方法。     

五倍子对菌斑生物膜内细菌的抑制作用

目的:应用人工口腔观察五倍子对菌斑生物膜内细菌的抑制作用。方法:采用液体二倍稀释法测定与致龋病关系较密切的4种细菌的最小抑菌浓度,并进一步在人工口腔中形成各实验菌的单一细菌菌斑生物膜,应用菌落计数技术观察五倍子水提取物对菌斑生物膜内细菌的抑制作用。结果:五倍子水提取物对变形链球菌、粘性放线菌、血链球菌、口腔链球菌的生长均有抑制作用,其中对变形链球菌、粘性放线菌和血链球菌的最小抑菌浓度(MIC)为64mg/ml,口腔链球菌为8mg/ml;不同浓度的五倍子水提取物对各实验菌形成的单一细菌菌斑生物膜均有一定的抑制作用,并呈浓度依赖性;即使采用大于MIC的浓度,也不能把釉质表面形成的生物膜完全抑制,釉质表面仍有细菌生长。结论:五倍子水提取物对菌斑生物膜内细菌具有良好的抑制作用;与浮游细菌相比,生物膜中的细菌对五倍子水提取物具有较强的抵抗力。     

三种漱口液对早期原位菌斑生物膜形成的影响

目的:应用口内牙菌斑生物膜模型评估替硝唑漱口液、西吡氯铵漱口液与氯己定漱口液对早期原位牙菌斑生物膜形成的影响.方法:在专业洁治后,志愿者佩戴一种上颌装置,6 个玻璃片置于装置内以形成口内菌斑生物膜.志愿者用指定漱口液每天漱口2 次,每次15 ml含漱1 min.48 h后样本从装置中移出,立即用2 种荧光染料染色,分别将死菌染成红色,活菌染成绿色,在激光共聚焦显微镜下观察,进行三维扫描,评估菌斑生物膜的厚度和活菌比率.在14 d洗脱期后,再应用另一种漱口液.结果:与清水相比, 3 种漱口液作用下的48 h菌斑生物膜平均厚度及平均活菌比率均有显著降低(P<0.001),且3 组之间有显著差异(P<0.05).结论:对于早期原位菌斑生物膜, 3 种漱口液均显示有抑制菌斑形成及抗菌的作用.     

菌斑生物膜原位干预模型的建立

目的 通过对原位菌斑生物膜发育过程及早期成熟菌斑生物膜的观察,探讨所建立的菌斑生物膜模型用于菌斑化学干预研究的可能性.方法 建立原位菌斑生物膜模型,运用激光共聚焦扫描显微镜结合荧光染色技术观察原位菌斑生物膜0～48 h的发育过程及48 h菌斑生物膜的活性和厚度.结果 可观察到0～48 h菌斑生物膜从无到形成到成熟,细菌排列趋于密集,菌斑厚度逐渐增加的过程.48 h的菌斑生物膜活性和厚度可检测.结论 建立的菌斑生物膜模型可观察原位菌斑的形成过程、形态及活性,适用于菌斑化学干预的研究.     

五倍子水提取物对菌斑生物膜形成过程中表面形态的影响

目的：研究五倍子水提取物在菌斑生物膜动态形成过程中对菌斑生物膜表面形态的影响。方法：采用液体二倍稀释法测得五倍子水提取物对变形链球菌、血链球菌、黏性放线菌标准株的MIC值分别为8、8、4mg／mL。在人工口腔环境下，用以上3种标准菌株在羟基磷灰石（HA）表面形成混合菌斑生物膜。在生物膜形成过程中，实验组以2mg／mL（低于3种菌株MIC值）的五倍子水提取物处理，对照组以生理盐水处理；在第6、24、48、72小时和第7天，通过扫描电镜（SEM）观察菌斑生物膜的表面形态。结果：各时期菌斑生物膜形态，实验组与对照组相比有明显差异。随着时间的变化，实验组HA表面细菌由散在分布逐渐聚集，形成简单的团块状或片状结构，而对照组细菌由疏松逐渐密集并增厚，形成较为典型的生物膜立体结构。结论：五倍子水提取物可以改变菌斑生物膜形成过程中的菌斑形态。     

刷牙及精油漱口液作用牙菌斑生物膜的体外观察

目的：建立体内收集牙菌斑生物膜的模型,比较刷牙及漱口液对不同时间形成的牙菌斑生物膜作用效果。方法：按纳入标准选取6名实验对象,配戴刻有凹槽的菌斑收集盘,6h、24h、48h分别取出,于激光共聚焦显微镜下观察并检测刷牙及精油漱口液作用后,原始生物膜厚度及其中活菌百分比的变化。结果：刷牙后6h、24h、48h菌斑生物膜的厚度均有减少,24h、48h生物膜厚度改变有显著性,且48h生物膜中活菌百分比由原来的51．03％降低至20．42％,差异有统计学意义（P〈0．05）。单纯使用漱口液可显著降低6h、24h、48h生物膜的活菌百分比（P〈0．05）,但与刷牙组比较,无显著性差异。对于48h生物膜,刷牙后使用漱口液可使生物膜中活菌百分比降低至3．25％,较单纯使用漱口液或单纯刷牙均有显著性降低（P〈0．05）。结论：刷牙能有效减少各时期形成的生物膜的厚度,漱口液可显著降低其中活菌百分比,但二者的作用效果无显著差别,刷牙后使用漱口液有助于提高漱口液的渗透杀菌效果。     

种植体愈合帽表面细菌生物膜结构初探

目的：研究口腔内纯钛种植体短期内表面细菌生物膜的结构，并探讨细菌生物膜结构与口腔卫生环境的相关性。方法：从12例种植患者获得术后6周复诊时取下的12枚完整的ITI种植体愈合帽，运用激光共聚焦显微镜对愈合帽表面生物膜的结构、分布等性质进行定性观察和定量分析，并分析了与牙菌斑指数的关系。结果：种植术后6周的12枚种植体愈合帽表面均广泛存在细菌生物膜，但分布不均，与愈合帽表面的位置有关。生物膜的厚度及范围与牙菌斑指数呈正相关。结论：术后短期内种植体愈合帽表面细菌生物膜的结构与口腔临床指标间存在一定的相关性。     

比较6种口腔材料对体外生物膜形成的影响

目的比较体外混合菌在不同充填材料表面形成早期生物膜的能力,探讨生物膜状态下不同充填材料细菌形成的差异。方法用6种不同修复材料按临床比例制成试件各3件,将各试件放入国际标准菌株牙龈卟啉单胞菌、具核梭杆菌、伴放线放线杆菌、粘性放线菌、血链球菌、变形链球菌混合培养24h,使之在试件表面形成生物膜。在激光共聚焦扫描显微镜(LCSM)下观察生物膜厚度和平均荧光强度,比较不同充填材料表面生物膜细菌形成的差异。结果形成的生物膜平均厚度依次为聚羧酸锌水门汀>磷酸锌水门汀>玻璃离子体水门汀>复合树脂>银汞合金>富士Ⅱ型玻璃离子水门汀。组间比较发现:四种充填材料生物膜厚度无统计学的差异,富士Ⅱ型玻璃离子水门汀、银汞合金的生物膜厚度与两种垫底材料之间都有显著性差异,复合树脂、玻璃离子体水门汀、磷酸锌水门汀的生物膜厚度与聚羧酸锌水门汀有显著性差异。结论材料表面形成的不同生物膜厚度提示:富士Ⅱ型玻璃离子水门汀、银汞合金具有较强的抑制生物膜形成的能力。     

自然牙菌斑生物膜模型的构建及应用

目的:构建人体内牙菌斑生物膜模型,观察不同时间自然形成菌斑生物膜的特点,体外观察精油成分漱口液对生物膜的渗透及杀菌效果。方法:按纳入标准选取6名志愿者,将刻有凹槽的羟基磷灰石圆片固定于活动夹板,配戴夹板,分别于6、24、48h取出圆片,于激光共聚焦显微镜下观察生物膜结构,检测总生物膜厚度,以及其中活菌厚度(μm)和荧光强度百分比(%)。观察各个时期形成的生物膜经漱口液作用1、5、15和30min后生物膜中活菌厚度及荧光强度的变化。应用SPSS13.0软件包进行随机区组单因素方差分析,SNK法进行均数两两比较。结果:6、24、48h形成的菌斑生物膜厚度分别为(11.92±4.63)μm、(18.63±4.66)μm和(27.55±6.35)μm,48h内菌斑生物膜逐渐增厚(P<0.05),尤以6h内增厚速度最快。不同时间形成的菌斑生物膜中,活菌厚度、荧光强度无显著差异(P>0.05)。6h形成的生物膜经漱口液作用,5min后活菌厚度和荧光强度即明显降低,15min后降至最低(P<0.01);24h和48h的生物膜则在漱口液作用15min后出现活菌厚度和荧光强度明显降低(P<0.05)。结论:本实验建立了体内收集...     

激光共聚焦扫描显微镜及其在牙菌斑生物膜研究中的应用

激光共聚焦扫描显微镜是近年来发展起来的一种激光扫描、计算机自动化分析与显微镜技术相结合的医学图像分析仪器,具有图像清晰、特异性高、敏感性强、三维重建、空间定位、精确定量等优点,成为形态学、分子细胞生物学、遗传学等领域中新一代强有力的研究工具.本文就激光共聚焦扫描显微镜基本原理及其应用于口腔牙菌斑生物膜的研究作一综述.     

五倍子水提取物对LPS抑制PDLC的ALP活性的影响

目的：观察五倍子水提取物对LPS抑制牙周膜细胞(Periodontal ligament cell，PDLC)的ALP活性的影响。方法：本实验采用细胞培养技术和酶联免疫技术，对LPS抑制PDLC的ALP活性的影响进行观察。结果：100μg／mL LPS可显著抑制ALP活性。加入五倍子水提取物后，对LPS抑制ALP活性有拮抗作用，该作用随五倍子水提取物浓度增加而增加，到10μg／mL时，达到峰值。另外，培养液中先加入不同浓度的五倍子水提取物溶液，培养24h后再加入LPS时(A组)，与LPS和五倍子水提取物溶液同时加入组(B组)相比，除对LPS抑制ALP活性有同样拮抗趋势外，A、B两组间比较，B组效果更佳。结论：五倍子水提取物对LPS抑制ALP活性具有保护作用。     

五倍子水提取物抑制LPS对牙周膜细胞附着牙骨质片表面的影响

目的观察五倍子水提取物对LPS抑制PDLC在牙骨质片表面附着的影响。方法采用细胞培养技术,细胞计数法及扫描电镜进行观察。结果加入五倍子水提取物溶液后,对LPS抑制PDLC在牙骨质片表面的附着有明显拮抗作用,该作用随五倍子水提取物浓度增加而增加,到10μg/mL时,达到峰值。另外,培养液中先加入不同浓度的五倍子水提取物溶液,培养24h后再加入LPS时(A组),与LPS和五倍子水提取物溶液同时加入组(B组)相比,除对LPS抑制PDLC在牙骨质片表面附着有同样拮抗趋势外,当五倍子水提取物浓度为10μg/mL、20μg/mL时,A组的细胞附着数明显高于B组。扫描电镜显示,A组与B组牙骨质片表面细胞数量较多,细胞形态丰满,细胞胞突伸展明显,并相互交织成栅栏状、网状结构,部分细胞呈叠层生长,其中A组效果更明显。结论五倍子水提取物对LPS抑制PDLC在牙骨质片表面附着有拮抗和保护作用。     

Effect of fluoride sustained slow-releasing device on fluoride, phosphate and calcium levels in plaque biofilms over time measured using ion chromatography

Objectives

To determine whether there are any differences in fluoride (F), calcium (Ca) or phosphate (PO₄) concentrations in natural plaque biofilms between the upper right and left quadrants using a fluoride sustained slow-releasing device (FSSRD) placed in the upper right quadrant after 7 and 21 days. To report and validate a new methodology in measuring very low concentrations of F in dental plaque and saliva using ion chromatography.

Methods

Twenty-one participants were divided into two groups with 11 participants in group one and 10 in group two. Each participant had a FSSRD attached to the upper right second permanent molar and two plaque generating devices (PGDs) attached to the upper right and left first permanent molars. The PGDs were recovered after 7 days in group one and 21 days in group two.

Results

At both 7 and 21 days (right, left), F (1.081 ± 1.517 ppm, 0.736 ± 0.840 ppm) and (0.459 ± 0.888 ppm, 0.203 ± 0.139 ppm), PO₄ (1053 ± 533 ppm, 654 ± 246 ppm) and (865 ± 1099 ppm, 474 ± 304 ppm) and Ca (136 ± 132 ppm, 74 ± 36 ppm) and (130 ± 109 ppm, 77 ± 24 ppm), were higher in the quadrant containing the FSSRD but not significantly so (p > 0.05). Fluoride and PO₄ fell in both quadrants between 7 and 21 days, though not significantly.

Conclusions

Intriguingly while not statistically significant, 21 day plaque contained less fluoride than those investigated after 7 days. While the data was not statistically significant, it seems possible that F, Ca and PO₄ accumulated around the device to a limited extent but were washed away fairly quickly and distributed around the oral cavity.

Clinical importance

The FSSRD was found to reduce dmfs/DMFS by 76% and raise salivary F levels by ∼10 folds. This device is very helpful in reducing dental decay where compliance is impaired such as in patients with special needs. This study further investigates the anti-cariogenic effect of this device.     

中药牙粉对龈上菌斑的控制效果

目的 探讨中药牙粉对龈上菌斑的控制效果。方法 符合纳入标准的35例患者随机分为实验组和对照组,检查口内每颗牙齿的牙龈指数、菌斑指数,洁治、抛光,统一刷牙方法,实验组用中药牙粉刷牙,对照组用安慰剂牙粉刷牙,3、7d复查牙龈指数和菌斑指数,实验结果秩和检验。实验设计为随机双盲平行对照。结果 实验组与对照组3d牙龈指数和菌斑指数都明显下降,实验组菌斑指数下降幅度高于对照组。7d多数受试者牙龈指数和菌斑指数有轻度上升,但实验组菌斑指数上升幅度低于对照组,且实验组7d菌斑指数与对照组相比有统计学差异,显著低于对照组。结论 在牙周基础治疗后,使用中药牙粉配合有效刷牙,可提高控制龈上菌斑的效果、减缓菌斑堆积。     

The effect of partial dentures and chlorhexidine gluconate gel on plaque accumulation in the absence of oral hygiene

A study was made of the effect of wearing partial dentures upon plaque accumulation in a group of 24 partial denture wearers, when oral hygiene procedures were withdrawn. The modifying effect of a 1% chlorhexidine gluconate gel on this plaque accumulation was measured. Plaque accumulation was measured at the end of four different denture-wearing regimens each 3 days in length. The wearing of a partial denture either day only or day and night, significantly increased plaque accumulation over not wearing a denture. There was no significant difference between plaque accumulation with day wear and day and night wear. The increase in plaque accumulation with day and night wear resulted from an equal and significant increase in both buccal and lingual plaque accumulation. Chlorhexidine gluconate in the form of a gel significantly reduced plaque accumulation during daytime wear. These results tend to confirm that plaque control is a major factor in determining the long-term effects of partial dentures upon the periodontal structures and emphasize the importance of oral hygiene in partial denture wearers.     

Effects of heat-inactivated Bifidobacterium BB12 on cariogenicity of Streptococcus mutans in vitro

ObjectiveSince some probiotic bacteria are cariogenic themselves, their suitability for caries management is questionable. Inactivated bacteria or their supernatants have been found to exert probiotic effects, whilst having several advantages compared with living bacteria. We hypothesized that viable and heat-inactivated Bifidobacterium animalis BB12 reduces the cariogenicity of Streptococcus mutans (SM) in vitro.DesignWe assessed mono- and mixed species biofilms of SM and viable or heat-inactivated BB12. Biofilms were grown in a continuous-culture-system under cariogenic conditions on smooth proximal enamel or cavitated dentine. For each of eight experimental subsets (4 biofilms × 2 hard-tissue conditions), a total of 32 specimens was used. After 10 days, bacterial numbers of 12 biofilms per group were analysed, and all specimens submitted to transversal microradiography.ResultsMineral loss was higher in cavitated dentine than smooth enamel for all biofilms (p < 0.001, t-test). BB12-monospecies biofilms induced significantly less mineral loss than SM in both enamel (p < 0.05) and dentine (p < 0.001). Viable BB12 did not significantly reduce cariogenicity of SM (p > 0.05), whilst heat-inactivated BB12 decreased cariogenicity of SM in dentinal cavities (p < 0.01). Bacterial numbers were higher on dentine than enamel (p < 0.05), but not significantly influenced by biofilm species (p > 0.05).ConclusionsHeat-inactivated BB12 reduced the cariogenicity of SM in dentinal cavities in vitro. Inactivated probiotics might be suitable for caries control.     

The in vitro effects of chlorhexidine on subgingival plaque bacteria

The purpose of this study was to determine the susceptibility to chlorhexidine of a range of bacteria which may be isolated from subgingival plaque. In addition, the effect of chlorhexidine on the survival of bacteria in subgingival plaque samples from patients with chronic inflammatory periodontal disease was investigated. The minimum inhibitory concentration (MIC) of chlorhexidine for 52 strains of bacteria ranged from 8 to 500 micrograms/ml. The modal value of the MIC was found to be 62 micrograms/ml, 64% of the strains tested being inhibited at this concentration. A concentration of 250 micrograms/ml of chlorhexidine inhibited the growth of all bacteria in the 25 subgingival plaque samples investigated. The MIC of chlorhexidine for the samples ranged from 31 to 250 micrograms/ml, the modal value being 125 micrograms/ml.