Inhibitory Effect of Yellow He-Ne Laser Irradiation Mediated by Crystal Violet Solution on Early Plaque Formation in Human Mouth

Abstract

. The purpose of this study was to evaluate the effect of yellow He-Ne laser irradiation in the presence of crystal violet (CV) solution on dental plaque formation in the human mouth. Four enamel specimens were fixed on a retainer, one of which was placed on both maxillary buccal sites of four subjects. The retainers were assigned randomly to 3- or 7-day experimental periods and the right or left buccal sites for the evaluation of plaque formation on the specimens. Then, the specimens were assigned randomly to four treatments as follows: A, laser irradiation; B, CV application; C, CV application and laser irradiation and D, no treatment (control). At three and seven days after the treatments, the inhibitory effects of plaque formation on the specimens were evaluated by measuring the thickness of the plaque on each section. Analysis of the plaque formation scores revealed that treatment C had a significantly greater inhibitory effect on plaque formation than treatment A, B and D after 3 days, however there were no significant differences among the plaque formation scores of the four treatment groups after 7 days. Analysis of the plaque thickness revealed that at both 3 and 7 days after treatment, the plaque layers after treatment C were significantly thinner than those after treatments A, B and D. These results indicated that yellow He-Ne laser irradiation in the presence of CV had an inhibitory effect of plaque formation in human mouth.