Tomiyama Kiyoshi, Mukai Yoshiharu, Kumada Hidefumi, Watanabe Kiyoko, Hamada Nobushiro, Teranaka Toshio
Am J Dent. 2015 Feb;28(1):13-7.
To simulate an oral demineralization environment by multiple species of bacteria by inducing subsurface dentin lesions with a polymicrobial biofilm model.
Polymicrobial biofilms consisting of multiple species of bacteria were generated from stimulated saliva using a high-throughput active attachment model. Biofilms were grown on dentin specimens in McBain medium containing 0, 0.2 or 2.5 ppm F and on glass without fluoride for 192 hours. The medium was refreshed twice daily, after 10 and 14 hours, until 72 hours, followed by treatment for 5 minutes with 400 ppm fluoride. Specimens were recovered after 192 hours. The number of colony forming units (CFU) was measured, and integrated mineral loss (IML) was determined by transversal microradiography.
Mineral profiles in specimens grown with 0.2F and 2.5F revealed surface layers and initial lesions distinct from those grown with 0F. IML was significantly lower with 0.2F and 2.5F than with 0F (P < 0.05), although CFUs were similar. CFUs of biofilms grown on dentin in medium containing 0F were 10-fold higher than on glass (P < 0.05). Subsurface lesions on dentin formed consistently, with their growth progression inhibited by application of fluoride. To our knowledge, this is the first report describing the induction of subsurface dentin lesions by a polymicrobial biofilm model, and this model may be useful for studies of demineralization supporting in situ and in vivo models.
通过多菌种生物膜模型诱导牙本质深层病变，模拟多种细菌导致的口腔脱矿环境。
使用高通量活性附着模型从刺激唾液中生成由多种细菌组成的多菌种生物膜。生物膜在含有0、0.2或2.5 ppm氟的McBain培养基中的牙本质标本上以及不含氟的玻璃上生长192小时。在10小时和14小时后，每天更换两次培养基，直至72小时，然后用400 ppm氟处理5分钟。192小时后回收标本。测量菌落形成单位（CFU）的数量，并通过横向显微放射照相术确定累积矿物质损失（IML）。
在含0.2F和2.5F培养基中生长的标本的矿物质分布显示，其表层和初始病变与在含0F培养基中生长的标本不同。尽管CFU相似，但0.2F和2.5F组的IML显著低于0F组（P < 0.05）。在含0F培养基中牙本质上生长的生物膜的CFU比在玻璃上高10倍（P < 0.05）。牙本质上的深层病变持续形成，氟的应用抑制了其生长进程。据我们所知，这是第一篇描述多菌种生物膜模型诱导牙本质深层病变的报告，该模型可能有助于支持原位和体内模型的脱矿研究。
