Objectives: A medicated chewing gum is a solid, single-dose preparation intended to be chewed for a certain period of time and deliver the drug. It may contain one or more than one active pharmaceutical ingredient. Whithin this context, we formulated a medicated gum with three active pharmaceutical ingredients: Camphor, p-chlorophenol and hydrogen peroxide, to be evaluated as therapeutic agents in dental caries. The aim of this study was to compare the effects on salivary streptococcus mutans, pH, buffer capacity and secretion rate of three medicated gums containing chlorophenol / hydrogen peroxide, xylitol or chlorhexidine. Methods: Double-blind, randomized crossover treatment in 24 subjects. The patients were randomized and subjected to six different treatment sequences. The subjects used, 1 gum tablet three times a day for 20 minutes, morning, noon and night. At the beginning and end of the three experimental phases saliva samples were obtained for determining the pH, buffer capacity, salivary flow rate and quantitative enumeration of S. mutans. Results: The use of medicated gum with camphor/p-chlorophenol and hydrogen peroxide did not modify the salivary chemical parameters measured, and not significantly reduced the number of S. mutans, after 7 days. Chewing gums with chlorhexidine significantly reduced the quantitative counting of S. mutans salivary and flow rate in a period of 7 days. Conclusions: The use of medicated chewing gums based on camphor / p-chlorophenol and hydrogen peroxide does not alter the chemical salivary parameters and does not significantly reduce the number of S. mutans, after a use over a period of 7 days.