The purpose of this study was to observe the degree of surface obliteration of dentinal tubule using Gluma(R) desensitizer and MS coat(R) with 15 specimens made out of 15 extracted lower incisors. They were divided into Root planning group(control), Gluma(R) desensitizer group(test I ) and MS coat(R) group(test II). Degree of Obliteration was examined under the scanning electron microscope(${ imes}$2000). The following results were obtained: 1. In the root planning group(control), the complete open of dentinal tubule surface was accounted for 73.8%, the partial obliteration for 17.2% and the complete obliteration for 9.0%. 2. In the Gluma(R) desensitizer group (test I), the complete open of dentinal tubule surface was accounted for 23.6%, the partial obliteration for 42.8% and the complete obliteration for 33.6%. 3. In the MS coat(R) group (test II), the complete open of dentinal tubule surface was accounted for 19.2%, the partial obliteration for 45.6% and the complete obliteration for 35.2%. 4. The average number of open dentinal tubules in the control was significantly higher than in the test I and II (P<0.05), but there were no statistically significant differences between the test I and II. 5. The average number of the partially obliterated and the completely blocked dentinal tubules in the control was significantly lower than the test I and II(P<0.05), but there were no statistically significant differences between the test I and II. The results of this study suggest that Gluma(R) desensitizer and MS coat(R) is significantly effective on dentinal tubule obliteration, therefore they were effective on hypersensitivity caused by periodontal treatment