The purpose of this study was to assess the antimicrobial and clinical effects of acid water mouthrinse prepared by an electrolysis apparatus on chronic periodontitis and to evaluate the lasting period of these effects.

The change in the pattern of colonization of bacteria within the subgingival pockets was monitored by phase contrast microscopy, in 40 patients, over a period of 8 weeks.

In addition, changes in the clinical parameters of the diseased sites were also monitored.

Site of pocket ≥ 5mm was selected in each patient randomly divided into two groups.

As a test group, acid water mouthrinse was used twice a day in 20 patients.

As control, no mouthrinse was used in 20 patients

The results were as follows:

The suppression of motile bacteria was maintained for up to 3-4 weeks at test group.

Two groups did not differ significantly in proportion of bacteria in subgingival plaque over a period of 8 weeks.

Loss of attachment showed a significant difference in test group and in test group compared with control group (P<0.05), but there was no significant difference in control group.

No statistical difference was shown in two groups concerning the gingival index, plaque index, bleeding index.

The results suggest that acid water mouthrinse is effective for reducing subgingival bacteria.

It can be concluded that acid water may be useful as an mouthrinsing agent.