Influence of optimal and excluded oral hygiene on early formation of dental plaque on plastic films. A quantitative and descriptive light and electron microscopic study

Abstract

The influence of oral hygiene on early plaque formation was studied. The amount and structure of dental deposits formed on plastic films were determined at occasions with or without a preceding period of effective oral hygiene. Six human subjects developed plaque during 4 h on plastic films applied to the buccal surfaces of premolars and cuspids. The plastic films with adhering deposits were processed for EM. In the presence of healthy gingiva, the plastic films were covered by a surface coating of acellular material in or on which bacteria, epithelial cells and leukocytes were observed. The microorganisms were almost exclusively Gram-positive cocci. When plaque formation was preceded by a week of excluded oral hygiene, the deposits collected on the same teeth exhibited a 3-fold increase in the number of bacteria. The relative composition of the flora was altered, as evidenced by a higher number of Gram-negative cells as well as the occurrence of rods and filamentous organisms. Neglect of oral hygiene apparently favors an earlier establishment of a complex bacterial flora at the dento-gingival region of the buccal surfaces of premolars and cuspids.