41 patients with sites having pocket depth of 4-6mm were selected for the study. We classified 2 groups which consisted of 21 patients in the test group(exp.) and 20 patients in the control(placebo) respectively. Following a baseline examination, plaque and calculus were removed and then the experimental gel were handed out to the patients and topical application regimens were initiated. During the 4-week experimental period, pocket depth, bleeding on probing, gingival index, plaque index as a clinical parameters were measured in the baseline, 2 weeks, 4 weeks respectively. A questionnaire was delivered to each patients in 2 weeks, 4 weeks respectively.

The results were as follows:

1.Probing pocket depth showed a significant difference in the Exp. group compared with the control group in the changes from baseline to 2 weeks(p<0.05), but there was no significant difference between the groups in the changes from baseline to 4 weeks, from 2 weeks to 4 weeks(p<0.05).

2.The Exp. group showed a significant difference compared with the control group in the changes from baseline to 2 weeks, from baseline to 4 weeks, from 2 weeks to 4 weeks in bleeding on probing(p<0.05).

3. The gingival index showed a significant difference compared with the control group in the changes from baseline to 2 weeks, from baseline to 4 weeks, from 2 weeks to 4 weeks after 4 weeks use of a gel(p<0.05).

4.The plaque index showed a significant difference in the Exp. group compared with the control group in the changes from baseline to 2 weeks(p<0.05), but there was no significant difference between the groups in the changes from baseline to 4 weeks, from 2 weeks to 4 weeks(p<0.05).

5.A questionnaire was consisted of 5 kinds as to bleeding, pus discharge, pain, burning sensation, patient's satisfaction and all of the questions showed a significant difference compared with the control group in the changes from 2 weeks to 4 weeks(p<0.05).

6.During the 4-week experimental period, important side-effects were not finded out, but each groups had one patient appealed nausea or discomfort respectively.

These results indicate that application of periodontitis-medical gel was useful as an additional aid of mechanical treatment.