Abstract: OBJECTIVE To investigate the quality situation of dental impression in different levels of medical institutions in Hangzhou,so as to provide basic data for improving the disinfection quality of dental impression. METHODS The contamination situations of dental impressions were investigated in 36 general hospitals,16 stomatological hospitals and 15 dental clinics in this study from Mar. 2017 to Sep. 2017.RESULTS A total of 458 microbiological samples were collected from 58 medical institutions with dental impression disinfection,and 224 samples were qualified,with the qualified rate of 48.91%. The dental impression qualified rates in general hospitals, stomatological hospitals and dental clinics were 52.51%(136/259), 62.40%(78/125), and 40.54%(30/74), respectively,which were significantly different(P=0.011).The highest qualified rate was stomatological hospitals, and the lowest qualified rate was dental clinics(P=0.003). Nine medical institutions did not perform disinfection on dental impression, and 56 samples were collected,with the qualified rate of 0%. Disinfection qualified rate of dental impression by immersion method was 73.97%(108/146), which was significantly higher than 43.59%(136/312)by spray disinfection(P＜0.001).CONCLUSION The contamination situation of dental impression is serious in medical institutions in Hangzhou, and disinfection quality is different among different levels of medical institutions. We should strengthen the training of disinfection knowledge and monitoring of dental impression.