The effect of irrigation with chlorhexidine or saline on plaque vitality

24 adult patients suffering from Adult periodontitis were assigned to 4 groups: the 1st rinsed for 1 min with 0.2% chlorhexidine gluconate (CHX); the 2nd group were irrigated for 15 s with 0.2% CHX in a pulsed oral irrigator; the 3rd group rinsed for 1 min with saline and the 4th group were irrigated for 15 s with saline. Plaque vitality was measured after the 4 experimental procedures, using the method described by Netuschil et al. and scored using the method described by Rundegren et al. The results showed that a single rinse or irrigation with 0.2% CHX solution decreased the % of viable micro-organisms, but the vitality of the bacteria remained unchanged in saline groups. Statistical analysis indicated that irrigation with CHX was more effective at reducing plaque vitality than rinsing with CHX.