Phase I clinical trial of a chlorhexidine diacetate intraoral delivery system in medically healthy gingivitis subjects

Chlorhexidine diacetate (CDA) was incorporated into an ethylene vinyl acetate (EVA) mouthguard. This single center, 5-week, open-label trial, evaluated six medically healthy subjects with moderate gingivitis. Subjects wore the mouthguard 12 hrs/day for 21 days.; Adverse events were recorded and the pharmacokinetic profiles of CDA in serum and saliva were evaluated. Plaque samples were evaluated for changes in microbial susceptibility to CDA, bacterial counts characterized under aerobic and anaerobic conditions, and specific subgingival microorganisms.; Results show limited adverse events, minimal systemic exposure to CDA, prolonged intraoral delivery, and no evidence of microbial CDA resistance. A reduction in the total bacterial counts of aerobic and anaerobic microbes, and an improvement in clinical signs of periodontal inflammation occurred.; Data suggest that the CDA-EVA mouthguard is safe for human use with minimal systemic exposure. Additionally, CDA treatment does not alter the CDA-susceptibility of the oral flora and may reduce total bacterial counts.