Objectives: The aim of this in vivo study was to compare the anti-plaque effect of warm and cold chlorhexidine gluconate irrigation on matured human plaque.
Methods: In a split-mouth design, the antibacterial effect of 47 degrees C "warm" 0.2% chlorhexidine solution was compared with that of 18 degrees C "cold" rinse at the same concentration on newly-formed supragingival plaque that had been left undisturbed for 72 h. Before and 1 h after a 1-min rinse procedure, plaque was sampled from 10 test persons and vitality determined using vital fluorescence technique.
Results: Cold and warm 0.2% chlorhexidine solution reduced plaque vitality significantly from 99.63% to 77.81% (p=0.014) and from 98.98% to 51.77% (p<0.001), respectively. Rinsing with warm chlorhexidine solution reduced plaque vitality to a significantly greater degree (p=0.003) than did cold chlorhexidine.
Conclusion: In this study, warm 0.2% chlorhexidine rinse showed a significantly more intensive anti-plaque effect than cold chlorhexidine solution at the same concentration.