Effect of toothpaste rinses compared with chlorhexidine on plaque formation during a 4-day period.

Abstract

Abstract Evidence suggests that brushing with a toothpaste may slow plaque reformation over 24 h. This study measured the effect of toothpaste alone on plaque regrowth over a 96 h period and compared the effect with water and the known antiplaque agent chlorhexidine. At 9 a.m. at the beginning of 7,4‐day no oral hygiene periods, 10 volunteers were scaled and polished. Al 5 p.m. subjects brushed their own teeth with water until plaque free. Each subject rinsed for I min with 10 ml of a randomly allocated rinse. Rinsing was repeated at 10 a.m. and 10 p.m. on subsequent days. The rinses were water, chlorhexidine 0.2% or 3 g/10 ml slurries of toothpastes containing (1) monofluorophosphate(MFP), (2) monofluorophosphate + sodium fluoride (MFP+NaF) (3) monofluorophosphate + zinc citrate (MFP+ZCT) (4) stannous fluoride (SnF2) (5) sodium fluoride (NaF). At 16, 24, 48 and 72 h plaque on the buccal surface of the upper and lower premolars, canines and incisors was scored by the Gingival Margin Plaque Index (GMPI) and gram films of plaque samples made. At 96 h plaque was recorded diagraromatically and areas of coverage measured visually (Debris Index) and by planimetry. Progressive plaque formation to a Gingival Margin Plaque Index of 100% at 72 h was observed for toothpaste and water rinses. For chlorhexidine the Gingival Margin Plaque Index at 72 h was 6%, At 96 h plaque areas were significantly less with toothpaste rinses compared with water. Chlorhexidine very significantly reduced plaque areas compared with toothpaste and water. The bacteriological assessment of smears revealed essentially similar plaque development during toothpaste and water rinses and was consistent with previous reports. However, with chlorhexidine the densities of organisms in the smears were greatly reduced. It was concluded that the small effect of toothpaste rinses on plaque accumulation compared with chlorhexidine would not alone represent a true antiplaque effect resulting in therapeutic benefit.