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.     

丁酸对牙周炎的影响机制研究进展

牙周炎是由牙菌斑微生物引起的牙周支持组织慢性感染性疾病。牙菌斑生物膜是引发牙周炎的始动因子。近年来牙周致病菌通过代谢氨基酸、己糖或戊糖无氧酵解产生的代谢产物——丁酸,引起了学者们的广泛关注。研究发现,牙周炎患者龈沟液中丁酸浓度显著高于健康组,牙周炎患者口腔中高浓度丁酸可能破坏牙周上皮组织的结构和功能,在牙周炎发生发展过程中起重要作用。本文就丁酸对牙周炎的影响机制作一综述。     

纯钛表面改性对细菌粘附的影响

目的：研究氮离子溅射和氮等离子浸没注入对纯钛表面细菌粘附能力的影响。方法：制作纯钛试件288件,各随机选出96件,分别采用氮离子溅射和氮等离子浸没注入对其表面改性,纯钛组为对照组,氮离子溅射组为实验1组,氮等离子浸没注入组为实验2组。在实验1、2组和对照组试件表面粘附血型链球菌、粘性放线菌、白色念珠菌和金黄色葡萄球菌,分别进行细菌体外粘附实验。用菌落形成单位计数法统计分析氮离子溅射和氮等离子浸没注入对各种细菌粘附量的影响。结果：在细菌粘附24h、48h、168h后,上述4种细菌在氮离子溅射组和氮等离子浸没注入组表面粘附量较对照组表面粘附量显著减少（P〈0.001）,其中4种细菌在氮等离子浸没注入组表面粘附量明显少于氮离子溅射组（P〈0.001）。结论：纯钛表面氮离子溅射和氮等离子浸没注入均可抑制细菌粘附,氮等离子浸没注入较氮离子溅射抑制细菌粘附效果更明显。     

The war on fraud and its effect on dentistry

The fraudulent actions of a disreputable few people in the health care industry have caused enormous losses to government and private health care payers. Fraud can take a number of forms, but usually is based on some form of deceit. In response, law enforcement efforts have been aided by a number of recent anti-fraud statutes and significant new resources. The challenge to dentistry is to ensure that legitimate efforts to fight fraud do not unduly burden practitioners, the vast majority of whom are honest.     

派丽奥(PERIOCLINE)治疗牙周炎临床疗效分析

目的 观察牙周炎局部治疗药物“派丽奥”（主要成份为盐酸二甲胺四环素,ＭＩＮＯ）治疗牙周炎的临床效果。方法 瑚机将７５名牙周炎病人共２００个牙周袋分成“派丽奥”实验组和合氏液对照组。观察用药前后临床太和菌斑指数、牙龈指数、龈沟出血指数、牙周袋深度、附着水平、牙齿松动度的变化。结果 两组用药前牙周各项指数的平均值均无差异（Ｐ〉０．０５）。用药后１周、停药１周、停药１月后均有差异或显著性差异（Ｐ〈０．０