Exclusion Criteria:patients with cavitated caries, no periodontal pockets larger than 4 mm, orthodontic appliances or removable prostheses, allergies to cetyl pyridinium or CHX, use of antibiotics and anti-inflammatory drugs in the past 3 months that might alter normal gingival health, oral prophylaxis outside of study; use of oral chlorhexidine products or participation in an oral rinse study within 3 months prior to baseline examination, pregnancy or nursing, smoking.