The purpose of this study was to determine the effect of chlorhexidine digluconate mouthrinses on the development of dental plaque in man. The dental plaques were formed on strips of triacetylcellulose film (TAC), which were attached to the lingual surfaces of the mandibular incisors by silk suture thread on 20 human volunteers.

Differences in the degree of plaque formation on TAC films after 2, 4 and 24 hours were observed in placebo vs. chlorhexidine treated samples using both scanning and transmission electron microscopy. It was found that (1) solutions containing chlorhexidine digluconate and lactic aluminum have an inhibitory effect of the development of dental plaque on the TAC film as evaluated by electron microscopy, (2) the TAC film was a convenient model for the study of early dental plaque formation by electron microscopy, (3) the three types of pellicle reported by Tryggve Lie (1977) were also observed, (4) the method enabled evaluation of the bacterial accumulation of TAC films. After 2 hours, there was no visible difference in the bacterial accumulations on placebo or chlorhexidine digluconate treated films. After 4 and 24 hours considerable differences were observed.