This placebo-controlled, double-blinded, randomized crossover study evaluates the plaque and gingivitis reducing capacity of Cetylpyridium Chloride (CPC) chewing gum, with mechanical oral hygiene. The study will enroll 73 students, faculty, and staff from the UTHealth School of Dentistry. Half of the eligible participants will be randomly assigned to get the CPC gum in the first treatment period (21 days), a wash-out period of 21 days, and then a placebo gum in the second treatment period (21 days). The other half will be assigned to follow the same schedule but with the treatment reversed. A statistician will perform the randomization. Primary outcomes are assessed by validated tools, such as the Plaque Index (PI), Gingival Index (GI), and percent of bleeding sites on probe (BOP).