Abstract: Objective: To detect the root surface after ultrasonic scaling under microscope and under direct vision. Methods: Ten extracted teeth with periodontitis were included. Twenty samples were randomly divided into 2 groups (microscope and direct vision), evaluated by methylene blue analysis. Six extracted teeth with periodontitis and 2 healthy teeth were chosen, and divided into 4 groups. They were examined by scanning electron microscope. Results: The differences of the residual calculus between microscope group and direct vision groups were statistically significant (P<0.05). Conclusion: Microscope can improve the effectiveness of ultrasonic scaling.

Key words: Ultrasonic scaling, Microscope , Scanning electron microscope