Authors: Cunningham WT, Joseph SW.
Title: Effect of temperature on the bactericidal action of sodium hypochlorite endodontic irrigant.
Journal: Oral Surg Oral Med Oral Pathol
Date: Dec 1980
Citation: 50(6):569-71
Category: Irrigants and Medicaments
Evidence-based Ranking: 5
Purpose/Objectives: To compare the bactericidal ability of 2.6% NaOCl irrigating solution when used at room temperature (22 degrees C) and at body temperature (37 degrees C). Materials & Methods: Five test microorganisms, E. coli, S. sanguis, B. subtilis spores, P. vulgaris and S. aureus were cultured and added to glass tubes. 2.6 % NaOCl at either 22 degrees C or 37 degrees C was added to the test tubes and portions of the sample were taken from the tubes at 15, 30, 45, 60, 90, 120, 180, 240, 300 and 600 seconds and were incubated for 48 hrs at 37 degrees C and were examined for bacterial growth. Results: Table 1 shows that 2.6% NaOCl at 37 degrees C requires significantly less time to kill the microbial flora tested than 2.6% NaOCl at room temperature (22 degrees C). AuthorÂ’s Conclusion: The time interval for 2.6% NaOCl to produce sterility of in vitro bacterial cultures was found to be significantly reduced at 37 degrees C compared to 22 degrees C. Validity of Conclusion: Conclusions are valid. ReviewerÂ’s Comments: This paper indicates that heating NaOCl will kill bacteria at least twice as fast as room temperature. Previous studies by the same author indicate that heating the NaOCl significantly increases its ability to dissolve organic tissue as well. The paper also mentions that the vapors from heated NaOCl have strong antimicrobial activity as well and may enhance the overall effectiveness of the irrigant in clinical endodontics.