几种酸性胶液与蛋白水解酶在人工龋形成中的作用

作者用自然牙菌斑内存在的几种有机酸制成胶液,观察它们在形成人牙釉质人工龋中的破坏作用。结果表明:甲酸胶液的破坏作用大于乙酸、乳酸或混合酸胶液;木瓜酶、胶原酶和胰蛋白酶对这个破坏过程未显示明显的组织学变化的影响。     

鸡蛋黄抗体IgY对人工菌斑形成的影响

目的 :研究特异性抗致龋菌鸡蛋黄抗体IgY在人工菌斑形成过程中对菌斑形态的影响。方法 :将制备好的牙釉质块放入含混合细菌菌液的培养基中培养 ,使之形成人工菌斑。在菌斑形成过程中实验组给予特异性IgY处理。在菌斑形成的第 1,3,5 ,7,14 ,2 1,2 8d ,取样本在扫描电镜下观察菌斑的形态。结果 :各时期经特异性IgY处理的菌斑形态与对照组有明显差异。经特异性IgY处理的菌斑中细菌有凝结成片层状的趋势 ,且细菌间基质减少。结论 :特异性IgY可改变人工菌斑形成过程中的菌斑形态     

两种脱矿体系制备人工龋损的病理学比较

目的评价两种不同脱矿体系在人牙釉质与牛牙釉质形成人工龋样损害的情况,确定模拟早期龋实验研究的脱矿系统。方法两种脱矿体系：部分饱和酸缓冲溶液和酸性凝胶溶液,分别在人牙釉质与牛牙釉质制备人工早期釉质龋损,采用偏振光显微镜和扫描电子显微镜观察实验人工龋的组织病理学变化。结果部分饱和的酸缓冲体系制备的人工龋损都具有完整的表层和表层下脱矿,牛牙釉质除了脱矿深度大于人牙釉质外,其它病理学特点都类似于人牙釉质,与早期自然龋损相似。而凝胶液脱矿体系形成的人工龋损不管是人牙还是牛牙都没有明显的表层结构,实验牙表面多出现被腐蚀或溶解。结论部分饱和的酸缓冲液脱矿系统形成的人工龋损病理学变化更接近于自然龋;与人牙具有相似化学组成的牛牙很适合代替人牙来检测脱矿和再矿化的效果。     

人工菌斑致谢牙釉质早期龋的研究

The authors used the cariogenic bacteria isolated from human dental plaque to produce an artificial plaque which can produce carious lesion in vitro. Lesions on human enamel slabs produced by artificial plaque and single bacterium were observed under polarized light microscope and scanning electron microscope. The results showed that the characters of artificial carious lesions are very similar to natural enamel caries. It is very difficult to differentiate them under the microscopes. Compared with the lesions produced by single strain, the destructive fashion observed in lesions produced by artificial plaque is more similar to the changes produced by natural dental plaque.     

蛋白水解酶在牙釉质脱矿中的作用

Papain, trypsin and collagenase were used in the experiment for the study of their effects on the demineralization of enamel surface by organic acids in vivo. No effect of any of the enzymes was observed. The use of papain and trypsin in treating tooth surfaces in vitro, no matter whether sodium bisulfite was used, showed no effect on the demineralization of the enamel by mixed organic acids. But, by the analysis of amino acids in the enzyme solutions before and after treating tooth surface, it was shown that some proteinous substances were destroyed. Accordingly, it can be suggested that the enzyme takes no part in the destruction of the inorganic tooth substance.     

牙本质生物人工龋的实验研究

目的:探讨生物人工牙本质龋模型建立的方法。方法:采用混合致龋菌、人工菌斑并用的方式,在模拟口腔获得性膜的基础上建立牙本质龋损标本,标本培养至45d和108d时进行偏光显微镜、落射光显微镜观察,并采用显微放射成像测量牙本质总脱矿量及脱矿深度。结果:该条件下模拟出的龋样损害在光镜下难以与真实龋相区别。结论:运用适宜菌种和实验方法可以在离体条件下建立牙本质人工龋模型。     

蛋白水解酶在牙釉质脱矿中的作用

本文报道用木瓜蛋白酶、胶原酶和胰蛋白酶,处理活体人牙,用木瓜蛋白酶和胰蛋白酶处理离体人牙,结果这些酶对有机酸对牙釉质的脱矿作用无明显的影响,但木瓜蛋白酶和胰蛋白酶对人牙釉质内的蛋白质有溶解作用。作者认为,即使牙菌斑内有溶解牙釉质内蛋白质的物质存在,但对牙釉质的脱矿却无明显影响。     

Multibacterial artificial plaque. A model for studying carious process.

A multibacterial artificial plaque was established in vitro on enamel slabs incubated in mixed culture of Streptococcus sanguis, Streptococcus mutans (serotype c), Streptococcus salivarius, Lactobacillus casei and Actinomyces viscosus. Typical structure same as natural plaque was seen under microscope. The caries-like lesion produced under the plaque was observed in enamel sections. The lesion was similar in appearance to natural ones under optic and scanning electron microscopes. The acids produced in both culture media and artificial plaque were similar in composition and type to those produced in natural plaque after sugar attack. It is suggested that this kind of plaque model may be useful in studying carious process in vitro, because it is easily controlled either by changing the composition of bacteria or by adding different kinds of nutrient in the media. Moreover, the results will be easier to explain than those produced in natural ones.

     

儿童龋齿病因综合分析及防治

龋齿是临床上的多发病、常见病。目前婴幼儿龋齿的发病率日见增高,严重的威胁着青少年儿童的身心健康和生长发育。致病原因有机体内外多种因素。因而预防该疾病就需要从发病原因的各个方面着手。釉质是防御龋病的重要屏障,在此阶段严密控防龋病的发生更有利于提高对龋病的防治能力。牙釉质组织由于受到遗传或机体内外各种因素影响就可使牙釉质在发育期发生物理、化学的改变,使组织结构变异或畸形。先天的发育缺陷、个体内环境差异、生存环境、生活方式、卫生习惯等各种因素都对牙釉质龋的发病有影响。龋齿的预防要从各个致病因素着手。从牙胚在胚胎期生成就开始加强孕妇的孕期卫生健康保健知识的宣传教育,保证胎儿正常发育。哺乳期科学喂养,注意口腔护理,使儿童养成良好的饮食和口腔卫生习惯,提高牙齿抗病能力。牙齿萌出后要随时检查,采用综合防龋措施预防龋齿的发生。发现问题早治早防。     

建立铜绿假单胞菌肺部感染动物模型的两种方法

目的 用两种方法建立家兔铜绿假单胞菌肺部感染模型,并根据病理学、影像学等指标进行评价、比较.方法 48只健康清洁级新西兰大白兔随机平均分成A、B、C、D4组,A组采用经皮气管穿刺法,B组采用经鼻喷雾吸入法,分别隔日接种铜绿假单胞菌反复感染家兔,C、D组施以无菌生理盐水分别作为穿刺对照组和吸入对照组.接种后隔日1次行胸部CT扫描.待家兔感染死亡后取肺脏进行病理学检查.从病理学、影像学和实验室检查等方面验证动物模型并对经皮气管穿刺法和经鼻喷雾吸入法两种建模方法进行比较评价.结果 (1)病理学指标:接种感染后早期死亡动物肺部均有不同程度的水肿、出血、结节样脓肿、实变表现,镜下可见肺组织内大量中性粒细胞浸润,灶状脓肿形成;感染死亡较晚动物的肺部实变逐渐减少,以局部肺不张、纤维增生、肉芽肿形成、淋巴细胞浸润为主要表现.(2)影像学指标:A、B两组胸部CT均表现为双侧多发斑片状模糊影,部分可见实变及脓肿灶.A组于接种后第5天CT影像上首先发现病变,B组接种后第7天发现病变.结论 使用经皮气管穿刺法和喷雾吸入法接种铜绿假单胞菌至新西兰兔肺部,均可成功建立兔铜绿假单胞菌急慢性病程演变的原发肺部感染模型;两种方法在可操作性、可控性、可适性等方面各有优点.