Citation Information :
Vijayaraghavan S, Menon K. Comparative Evaluation of Human Pulp Tissue Dissolution by 500-ppm and 200-ppm Hypochlorous Acid and 5.25% Sodium Hypochlorite: An In Vitro Study. J Contemp Dent Pract 2023; 24 (2):103-106.
Aim: The aim of this study was to assess, in vitro, the human pulp dissolution capacity of 500 ppm and 200 ppm of hypochlorous acid in comparison with 5.2% sodium hypochlorite (NaOCl).
Materials and methods: Forty pulp tissue samples were standardized to a weight of 9 mg and divided into four groups according to the irrigating solution used: 5.25% NaOCl, 500 ppm hypochlorous acid, 200 ppm hypochlorous acid, and distilled water. Eppendorf tubes carrying 2 mL of the irrigants were taken and the pulp tissue samples were placed in the tubes for the specified time interval: Subgroup A: 30 minutes and subgroup B: 60 minutes. After the designated time interval, the solution from each sample tube was filtered using Whatman filter paper and left for drying overnight. The residual weight was calculated by filtration method. The mean dissolution time for each experimental group at the different time intervals was statistically analyzed.
Results: Mean tissue dissolution increases with an increase in the time period. Approximately 5.25% NaOCl was most effective at both time intervals followed by 500-ppm hypochlorous acid at 60 minutes. Least amount of tissue dissolution was shown by 200-ppm of hypochlorous acid at 30 minutes. Distilled water did not show the ability to dissolve human pulp tissue.
Conclusion: Within the limitations of the study, 5.25% NaOCl dissolved the pulp tissue most efficiently at both time intervals and both concentrations. Human pulp tissue dissolution by hypochlorous acid was found to gradually increase with time and with an increase in its concentration.
Clinical significance: With the basic information that hypochlorous acid does have the capacity to dissolve human pulp tissue, further research can be undertaken to assess methods to increase its efficiency. Sooner than later, hypochlorous acid may be able to completely replace the toxic NaOCl in clinical practice, as the irrigant of choice during root canal therapy.
Ricucci D, Siqueira JF Jr, Bate AL, et al. Histologic investigation of root canal-treated teeth with apical periodontitis: A retrospective study from twenty-four patients. J Endod 2009;35(4):493–502. DOI: 10.1016/j.joen.2008.12.014.
Cobankara FK, Ozkan HB, Terlemez A. Comparison of organic tissue dissolution capacities of sodium hypochlorite and chlorine dioxide. J Endod 2010;36(2):272–274. DOI: 10.1016/j.joen.2009.10.027.
Haapasalo M, Shen Y, Qian W, et al. Irrigation in endodontics. Dent Clin North Am 2010;54(2):291–312. DOI: 10.1016/j.cden.2009.12.001.
Iqbal A. Antimicrobial irrigants in the endodontic therapy. Int J Health Sci (Qassim) 2012;6(2):186–192. DOI: 10.12816/0005998.
Dube K, Jain P. Electrolyzed saline: An alternative to sodium hypochlorite for root canal irrigation. Clujul Med 2018;91(3):322–327. DOI: 10.15386/cjmed-863.
Hiebert JM, Robson MC. The immediate and delayed post-debridement effects on tissue bacterial wound counts of hypochlorous acid versus saline irrigation in chronic wounds. Eplasty 2016;1(16):e32. PMID 28123629.
Aherne O, Ortiz R, Fazli MM, et al. Effects of stabilized hypochlorous acid on oral biofilm bacteria. BMC Oral Health 2022;22(1):415. DOI: 10.1186/s12903-022-02453-2.
Taneja S, Mishra N, Malik S. Comparative evaluation of human pulp tissue dissolution by different concentrations of chlorine dioxide, calcium hypochlorite and sodium hypochlorite: An in vitro study. J Conserv Dent 2014;17(6):541–545. DOI: 10.4103/0972-0707.144590.
Andrés CMC, Pérez de la Lastra JM, Juan CA, et al. Hypochlorous acid chemistry in mammalian cells: Influence on infection and role in various pathologies. Int J Mol Sci 2022;23(18):10735. DOI: 10.3390/ijms231810735.
Robson MC, Steed DL, Franz MG. Wound healing: Biologic features and approaches to maximize healing trajectories. Curr Probl Surg 2001;38(2):72–140. DOI: 10.1067/msg.2001.111167.
Zehnder M. Root canal irrigants. J Endod 2006;32(5):389–398. DOI: 10.1016/j.joen.2005.09.014.
Wang L, Bassiri M, Najafi R, et al. Hypochlorous acid as a potential wound care agent: Part I. Stabilized hypochlorous acid: A component of the inorganic armamentarium of innate immunity. J Burns Wounds 2007;6:e5. PMID 17492050.
United States Environmental Protection Agency (homepage on the Internet), US. 2020. August 20 List N: disinfectants for use against SARS-CoV-2 (COVID-19). Available from: https://www.epa.gov/pesticide-registration/list-n-disinfectants-use-against-sars-cov-2-covid-19. Accessed March 2, 2023.
Drozdzik A, Drozdzik M. Oral pathology in COVID-19 and SARS-CoV-2 infection: Molecular aspects. Int J Mol Sci 2022;23(3):1431. DOI: 10.3390/ijms23031431.
Estrela C, Estrela CR, Barbin EL, et al. Mechanism of action of sodium hypochlorite. Braz Dent J 2002;13(2):113–117. DOI: 10.1590/s0103-64402002000200007.
Hand RE, Smith ML, Harrison JW. Analysis of the effect of dilution on the necrotic tissue dissolution property of sodium hypochlorite. J Endod 1978;4(2):60–64. DOI: 10.1016/S0099-2399(78)80255-6.
Gordon TM, Damato D, Christner P. Solvent effect of various dilutions of sodium hypochlorite on vital and necrotic tissue. J Endod 1981;7(10):466–469. DOI: 10.1016/S0099-2399(81)80308-1.