Influence of pre-soaking and different time intervals in ultrasonic cleaner on sterilization of endodontic files

Endodontic treatment may directly involve contact with saliva, blood and infected pulp tissue. So, cross infection is the major issue in endodontic treatment. All instruments should be cleaned prior to sterilization using methods like pre-soaking and ultrasonic cleaning. Contaminated instruments are pre-soaked prior to ultrasonic cleaning. This study investigated the effect of pre-soaking of instruments prior to ultrasonic cleaning on sterilization. Endodontic files were divided into 10 groups. Group 1 to Group 4 includes pre-soaking and ultrasonic cleaning with different time intervals. Group 5 to Group 8 includes no pre-soaking but ultrasonic cleaning with same time intervals as above groups. Group 9 and 10 were control groups. Group 1-4 instruments were pre-soaked before ultrasonic cleaning. Then all instruments from Group 1-8 were subjected to ultrasonic cleaning. Then all instruments were sterilized using autoclave. Visualization and scoring of debris is done at tip and blade of the file. There was no significant difference with pre-soaking of instruments before ultrasonic cleaning but ultrasonic cleaning has significant effect on cleanliness of files with time intervals of 5-10 mins. There were no further improvement upto 1 hr. This was concluded that there is no improvement in cleanliness of instruments with pre-soaking and optimum ultrasonic cleaning time was 5-10 mins.