RESUMEN
Introduction: A thorough endodontic files decontamination protocol, prior to sterilization, is extremely important. Retentions existing in the files active part hinder asepsis, and inadequate cleaning interferes with the sterilization process. Thus, the aim of this study was to evaluate the endodontic files contamination used by undergraduate students from the University Southern Santa Catarina (Unisul), after cleaning and sterilization process. Materials and Methods: Dentistry undergraduate students from the 6th to the 10th period at Unisul, Pedra Branca unit, participated in the research. Endodontic files, caliber # 40, # 45 or # 50, were collected from the sterile metal box and then incubated in a broth culture medium, at 37ºC, in aerobiosis. After 48 hours, the culture medium was evaluated for turbidity, which would indicate the instrument contamination. The total number of contaminated samples for each period was computed and the data statistically analyzed by the chi-square test (α = 5%). Results: A total of 98.46% of the files were sterile. Only 1 file, from a 10th period student, showed contamination. There was no association between the contamination presence and course period (P > 0.05). Conclusion: The endodontic files cleaning and sterilization process is being carried out effectively by dentistry undergraduate students from the 6th to the 10th period at Unisul, Pedra