Nyvad B, Fejerskov O
Department of Oral Anatomy, Royal Dental College, Aarhus, Denmark.
Caries Res. 1989;23(3):151-8. doi: 10.1159/000261169.
This study describes the ultrastructure of dental plaque and the plaque-enamel interface after 2 and 3 weeks' exposure to a cariogenic challenge. Five dental students carried a total of 25 specimens of smooth surface enamel in intraoral acrylic appliances. During the initial 3 days the volunteers refrained from oral hygiene and performed nine daily mouthrinses with 10% (w/v) solutions of sucrose. After the 3rd day the volunteers cleaned their natural teeth, whereas the experimental sites were left undisturbed except for nine daily extraoral 5-min immersions in 5% (w/v) solutions of sucrose. Clinically, three patterns of colonization were observed after 3 days. At the histological level the experimental bacterial deposits also exhibited three distinctly different structural patterns after 2 and 3 weeks. Individual patterns consistently differed with regard to the microbial composition, the structural organization of the deposits, and the presence or absence of crystal-like material. However, in all individuals a layer of densely packed gram-positive bacteria resembling Actinomyces was consistently present close to the enamel surface. In 1 individual the microbial deposits were dominated by large bacteria, the ultrastructure of which conformed to the description of Stomatococcus mucilaginosus. These findings may partly explain pronounced individual variations in the rate of caries lesion development and progression in vivo.
本研究描述了在遭受致龋挑战2周和3周后牙菌斑及菌斑 - 牙釉质界面的超微结构。五名牙科学生在口腔内丙烯酸装置中总共携带了25个光滑表面牙釉质标本。在最初3天，志愿者不进行口腔卫生护理，每天用10%（w/v）蔗糖溶液进行9次漱口。第3天后，志愿者清洁其天然牙齿，而实验部位除每天9次在5%（w/v）蔗糖溶液中进行5分钟口外浸泡外，保持原状。临床上，3天后观察到三种定植模式。在组织学水平上，实验性细菌沉积物在2周和3周后也呈现出三种明显不同的结构模式。个体模式在微生物组成、沉积物的结构组织以及晶体样物质的有无方面始终存在差异。然而，在所有个体中，靠近牙釉质表面始终存在一层密集排列的革兰氏阳性菌，类似于放线菌。在1名个体中，微生物沉积物以大型细菌为主，其超微结构符合粘液性口腔球菌的描述。这些发现可能部分解释了体内龋损发展和进展速度明显的个体差异。
