摘要：An appliance model was used in this study to determine the predominant cultivable microflora involved in early dental plaque formation on human enamel surfaces. Twelve enamel slabs were mounted on either side of an intraoral appliance, and the device was worn for periods of 48 h under (1) 'normal' conditions, and (2) with extraoral sucrose applications, nine times daily. Plaque samples were removed from the surface of different slabs at various time-periods, and the bacterial composition determined, with the 4036 isolates being expressed both as percentage and absolute counts. Streptococcus species dominated the plaque microflora at all sampling times, with S. oralis and S. sanguis predominating. A significant increase in total bacterial counts per mm2 enamel occurred from 2 to 48 h, and although sucrose had little effect on the percentage counts of organisms, most genera and species were present in significantly higher numbers per mm2 enamel in sites exposed to sucrose. This study demonstrates the importance of expressing results as absolute as well as proportional counts. Furthermore the appliance appears to offer some advantages over previously used models since (1) the use of multiple slabs allows longitudinal studies to be performed and (2) two experimental conditions can be investigated simultaneously, one on each side of the mouth.Keywords: Intraoral appliance; Enamel slabs; Dental plaque.
