The comparative study was carried out on a sample of 15 patients treated with two mouthwashes both containing 0.2% chlorhexidine, but different in that the first does not contain ADS, which is instead present in the second, a new product. The results obtained show that in the 15 patients treated, there is no statistically significant difference in the ability of the mouthwash to prevent bacterial plaque, however evidence of the stain was much less with the new mouthwash.