The present study investigate the effect of newly designed toothbrush(Chess tip : experimental group), conventional toothbrush(control group) on plaque control, gingivitis, and periodontitis. The results of 4weeks post-research by clinical comparison between the two groups are as follows. 1. In analysis of plaque index between groups there was Significant difference in the experimental group at 2,4 week. 2. In analysis of gingival index between groups there was significant difference in the experimental group at 1,2,4 week. 3. Both experimental group and control group showed decrease in periodontal pocket depth after 4week, but there was significant difference in the experimental group at 4 week. 4. Both experimental group and control group showed decrease in bleeding on probing after 4week, but there was significant difference in the experimental group at 4 week. These results indicate that newly designed toothbrush has beneficial effects as additional aid of mechanical treatment at the point of periodontal pocket, plaque control, and bleeding on probing.