Weiger R, Netuschil L, von Ohle C, Brecx M
Department of Conservative Dentistry, University of Tübingen, Germany.
J Periodontal Res. 1995 May;30(3):204-9. doi: 10.1111/j.1600-0765.1995.tb01275.x.
Although vital plaque micro-organisms are part of the natural ecosystem in the oral cavity they are also the key factor in the development of diseases induced by the human dental plaque. In a previous study (9) the portion of vital bacteria related to the total number of plaque micro-organisms (i.e. the microbial vitality) appeared low in small plaque samples. The objective of this investigation was to determine the exact relationship of microbial vitality and age of supragingival plaque during the early phases of human dental plaque formation. Between intervals of optimal oral hygiene, thirteen participants refrained from all oral hygiene measures for periods of 1, 2, 4, 8, 24 and 72 h. Plaque was completely sampled from a defined area situated on the vestibular surface of the teeth 13, 14, 15, 23, 24 and 25. The pooled plaque from these areas was immediately processed. Total bacterial counts (BC) as enumerated by darkfield microscopy, and colony-forming units (CFU) were recorded. The microbial vitality was calculated indirectly as plating efficiency (PE = CFU per BC) and directly assessed using a vital fluorescence (VF) technique. In the 1 h old plaque samples the median values of PE and VF were 29% and 18%, respectively. Thereafter, the microbial vitality increased significantly with plaque age. The 24 h old plaque samples yielded values of 77% (PE) and 62% (VF). It was concluded that the microbial vitality of the early dental plaque investigated was considerably lower compared to that of a more mature plaque.
尽管活的菌斑微生物是口腔自然生态系统的一部分，但它们也是人类牙菌斑引发疾病的关键因素。在之前的一项研究中（9），在小的菌斑样本中，与菌斑微生物总数相关的活细菌比例（即微生物活力）似乎较低。本研究的目的是确定在人类牙菌斑形成早期，微生物活力与龈上菌斑年龄的确切关系。在最佳口腔卫生间隔期间，13名参与者在1、2、4、8、24和72小时内停止所有口腔卫生措施。从位于牙齿13、14、15、23、24和25前庭表面的特定区域完全采集菌斑。这些区域的混合菌斑立即进行处理。记录通过暗视野显微镜计数的总细菌数（BC）和菌落形成单位（CFU）。微生物活力通过间接计算平板效率（PE = 每BC的CFU）和使用活荧光（VF）技术直接评估。在1小时龄的菌斑样本中，PE和VF的中值分别为29%和18%。此后，微生物活力随着菌斑年龄显著增加。24小时龄的菌斑样本中，PE值为77%，VF值为62%。得出的结论是，与更成熟的菌斑相比，所研究的早期牙菌斑的微生物活力要低得多。
