The purpose of this paper is to compare the effect of daily consumption of two sugar-free chewing gum, one with Recaldent and one with Xylitol, added to traditional hygiene (brushing, fluoridated toothpaste and dental floss), in clinical features such as the accumulation of plaque and gingival inflammation, microbiological characteristics of saliva as the counts of cariogenic microorganisms and facultative anaerobes, and some physicochemical properties of saliva such as pH and concentrations of calcium and inorganic phosphate.