To ascertain effectiveness of pre-sterilization cleaning of endodontic instruments before placement in glass bead sterilizer – An in vitro study

Introduction: In endodontics, reuse of sterilized endodontic instruments is a common practice. During biomechanical preparation of root canal, various organic and inorganic residual debris accumulates on working sections of endodontic instruments. This debris may act as potential antigens or infectious agents, hence cleaning of contaminated endodontic instruments play a vital role in effectively sterilizing the instruments. Aim: Evaluation of pre-sterilization cleaning of endodontic instruments by using 3% H2O2 & 2% glutaraldehyde manually & with ultrasonic bath. Methodology: Fifty, K files (15 No.) were contaminated by preparing canals of extracted human mandibular teeth. Instruments were divided in five groups of 10 instruments each and different cleaning protocols were applied to each group. The selected endodontic instruments were then immersed in Van-Gieson’s stain and debris was evaluated under stereomicroscope for scoring .The data obtained was statistically analysed using Kruskal- Wallis Test, Wilcoxon Rank Sum Test & Pearson Chi-square Test. Results:  81% of the selected samples showed residual debris. Combination of mechanical and chemical (2% glutaraldehyde) cleaning procedure followed by ultrasonic bath was found to be an effective method of removing debris from endodontic instruments. There was a statistically significant difference in the mean values with respect to the various cleaning protocol applied (P < 0.001). Conclusion: The effect of immersing endodontic instruments in 3% Hydrogen Peroxide & 2% glutaraldehyde was comparable. The ultrasonic method was found to be more effective than chemical & mechanical methods. Keywords: Biological debris, Endodontic instruments, Infection control, Pre-sterilization