The effect of toothbrushing regimens on the plaque inhibitory properties of an experimental cetylpyridinium chloride mouthrinse.

OBJECTIVE: The objective of this study was to determine the effect of various toothbrushing regimens with a standard fluoride dentifrice on the plaque inhibitory properties of an alcohol-free, high bioavailable 0.07% cetylpyridinium chloride (CPC) mouthrinse.

MATERIALS AND METHODS: The study was a randomized, single-centre, examiner blind, four-period cross-over study involving 29 healthy subjects. Four treatment regimens were evaluated: (1) Toothbrushing with dentifrice followed by a water rinse (B-W, negative control); (2) Toothbrushing with dentifrice followed by a CPC mouthrinse use (B-CPC); (3) Toothbrushing with dentifrice followed by a water rinse and then a CPC mouthrinse use (B-W-CPC); and (4) Toothbrushing with dentifrice and waiting 60 min. prior to a CPC mouthrinse use (B-60 min.-CPC). Three days before the baseline exam of treatment periods, subjects were instructed to brush only the lingual surfaces of their teeth for up to 60 s twice daily. At baseline, subjects received a plaque exam using the Turesky modification of the Quigley-Hein index (MQH) followed by a polishing on the lingual and buccal surfaces of their teeth. During treatment periods, subjects were asked to brush only the lingual surfaces of their teeth with a standard fluoride dentifrice. Rinsing with 20 ml of the experimental CPC solution was done for 30 s twice daily. The evening before the last day of treatment periods (Day 4), subjects were asked to refrain from any oral hygiene, eating, and drinking after brushing. On Day 4, plaque was scored using the MQH Index. A 10-day wash-out of normal oral hygiene was allowed between each of the four treatment periods. The data were analysed using analysis of covariance for cross-over designs.

RESULTS: Twenty-five to 29 subjects were evaluable at any given visit. With respect to unbrushed buccal and brushed lingual surfaces, all three CPC regimens had highly significantly (p < or = 0.0006) lower mean plaque scores than the B-W regimen, reductions ranging from 20% to 38% in magnitude. With respect to unbrushed surfaces, there was a significant difference between the B-CPC regimen and the B-60 min.-CPC regimen (p < 0.01) in favour of the latter regimen. No other pairwise treatment comparisons were statistically significant for unbrushed sites. Results for brushed surfaces and all sites combined showed that both the B-W-CPC and the B-60 min.-CPC groups reduced mean plaque levels significantly (p < or = 0.013) more than B-CPC. There were no statistically significant differences between B-W-CPC and B-60 min.-CPC for measurements of brushed, unbrushed, or all sites combined.

CONCLUSIONS: Results show that the alcohol-free, 0.07% high bioavailable CPC rinse provides an additive anti-plaque benefit beyond toothbrushing with a standard fluoride dentifrice regardless of the regimen. Of the regimens, a water rinse between toothbrushing and CPC rinsing enhances therapeutic efficacy while fitting into the patient's typical oral hygiene routine.