Matharu S, Spratt D A, Pratten J, Ng Y L, Mordan N, Wilson M, Gulabivala K
Department of Conservative Dentistry, Eastman Dental Institute for Oral Health Care Sciences, University College London, UK.
Int Endod J. 2001 Oct;34(7):547-53. doi: 10.1046/j.1365-2591.2001.00475.x.
The aim of this study was to develop an in vitro model to replicate microbial microleakage at a tooth/ restoration interface using a constant depth film fermentor (CDFF).
Amalgam restorations were placed in machined bovine dentine cylinders and sealed externally with varnish, leaving a 1-mm perimeter exposed around the tooth/restoration interface. The dentine cylinders were housed in a CDFF and 300-microm thick microcosm dental plaques were grown over their exposed surfaces. The biofilms were maintained with a mucin-containing artificial saliva for up to 8 weeks. Cylinders were aseptically removed from the CDFF (at 1, 2, 4, & 8 weeks) and surface-decontaminated with validated protocols prior to splitting and sampling of apposing amalgam and dentine surfaces. Scanning electron microscopy (SEM) was used to ascertain the position and structure of the bacterial aggregates. Bacterial viability was determined by vital staining of the bacteria in situ.
At all sampling times, SEM showed cocci, rods and filaments on both amalgam and dentine surfaces; some originated as cascades from the surface biofilm and extended into the tooth/restoration microspace. Vital staining showed the majority of bacteria from both dentine and amalgam surfaces to be viable.
This preliminary investigation showed that the CDFF may be a valuable tool for the in vitro study of the dynamics of microbial microleakage around dental restorations.
本研究的目的是开发一种体外模型，使用恒深膜发酵罐（CDFF）在牙齿/修复体界面复制微生物微渗漏。
将汞合金修复体置于加工过的牛牙本质圆柱体中，并用清漆进行外部密封，在牙齿/修复体界面周围留出1毫米的周边暴露区域。将牙本质圆柱体置于CDFF中，在其暴露表面生长300微米厚的微观牙菌斑。用含粘蛋白的人工唾液维持生物膜长达8周。在第1、2、4和8周时，将圆柱体无菌地从CDFF中取出，在劈开并对相对的汞合金和牙本质表面进行取样之前，用经过验证的方案进行表面去污。使用扫描电子显微镜（SEM）确定细菌聚集体的位置和结构。通过对细菌进行原位活染来确定细菌活力。
在所有取样时间，SEM显示汞合金和牙本质表面均有球菌、杆菌和细丝；一些起源于表面生物膜的级联，并延伸至牙齿/修复体微间隙。活染显示牙本质和汞合金表面的大多数细菌均具有活力。
这项初步研究表明，CDFF可能是体外研究牙科修复体周围微生物微渗漏动态的有价值工具。
