Short-term relative antibacterial effect of octenidine dihydrochloride on the oral microflora in orthodontically treated patients

Summary Objective To evaluate the efficacy of common antiseptic mouth rinses and octenidine dihydrochloride (OCT). Methods The antibacterial activities of antiseptics against total and cariogenic bacteria ( Streptococcus mutans and Lactobacillus species) in saliva were studied in vitro and in vivo. After unstimulated saliva was collected, one of the mouth rinse solutions was applied for 30 seconds. Saliva samples were collected 15, 30, 60, and 120 min later and evaluated for their bacterial count. Results OCT had a significantly greater inhibitory effect on the studied bacteria than 0.2% chlorhexidine gluconate (CHX) and 7.5% polyvinylpyrrolidone–iodine complex (PVP–I) from 15 min to 120 min following the application ( p < 0.01). The antiseptic efficacy of 0.2% CHX on total bacteria and Lactobacillus species was very similar to the efficacy observed with 7.5% PVP–I mouth solution from 15 min up to 120 min. Streptococcus mutans was completely inhibited by 0.15 mg/ml PVP–I, 0.5 mg/ml CHX, and 0.1 mg/ml OCT concentrations, while Streptococcus salivarius was inhibited by 0.15 mg/ml PVP–I, 2 mg/ml CHX, and 0.8 mg/ml OCT concentrations. Lactococcus lactis subspecies lactis was inhibited with 0.00313 mg/ml OCT, 30 mg/ml PVP–I, and 0.0063 mg/ml CHX concentrations. Conclusions OCT compared favorably with CHX and PVP–I in its antibacterial effects, both in vitro and in vivo ( p < 0.01).