Periodontal disease is caused by accumulation of bacterial plaque. For the reason, plaque control is essential to control and prevent periodontal disease. Among the plaque control methods, mechanical plaque removal, tooth brushing is common and reliable. But it depends on individual habituation and their manner. To catch up the gap of effectiveness, lots of oral hygiene appliances have been developing. Powered toothbrush is the most interesting field and is showing on the market with various motion type. This study was performed to compare clinical effects of plaque removal between powered toothbrush and manual toothbrush. The results were as follows : 1. Plaque index was decreased statistically after the brushing than before the brushing in every group.(p<0.05) 2. Comparing plaque index among the three groups before and after brushing, there were no statistically significant differences. 3. Interproximal plaque index was decreased statistically after the brushing than before the brushing in every group.(p<0.05) 4. Comparing interproximal plaque index among the three groups before and after brushing, there were no statistically significant differences.