Objective To evaluate the protective effect of patient's protective mask on oral spray during periodontal scaling. Methods Ultrasonic scaling was simulated by simulated human in dental clinic to test the protective effect of a new protective mask for patients. The test was divided into six groups according to the teeth position and protective methods(group 1: Upper right anterior teeth + low volume saliva ejector; group 2: Upper right anterior teeth + low volume saliva ejector+ high volume saliva ejector; group 3: Upper right anterior teeth + low volume saliva ejector + new protective mask; group 4: Lower right anterior teeth + low volume saliva ejector; group 5: Lower right anterior teeth + low volume saliva ejector+ high volume saliva ejector; group 6: Lower right anterior teeth + low volume saliva ejector + new protective mask). The spattering range and percentage of spattering area during simulated ultrasonic scaling among groups were compared. Results The spattering range and the percentage of spattering area on white paper were both 0 in group 3 and group 6 (using low volume saliva ejector + new protective mask, whether it was upper right anterior teeth or lower right anterior teeth), while group 1, 2, 4 and 5 (only use low volume saliva ejector or combined with high volume saliva ejector) produced spatter of certain range, and percentage of spattering area were (1.34±0.56)%-(24.48±7.43)%. Conclusion The new protective mask can effectively stop oral spattering during ultrasonic scaling.