Statistical analysis
After excluding subjects (1) with missing data from Day 0, Day 1, and after 3 weeks; (2) not satisfying the eligibility criteria; (3) orally or intravenously taking substances (e.g., antibacterial drug, antibiotics) potentially affecting the oral microflora during the study; (4) requiring dental treatment; and (5) showing poor compliance with CPC spray (use rate of less than 80%), the remaining subjects were included in statistical analyses. Age was analyzed by the independent‐samples 