Effectiveness of calcium and sodium hypochlorite associated with passive ultrasonic irrigation on pulp tissue dissolution – An in vitro study

  • Matheus Albino Souza Universidade de Passo Fundo
  • Ana Paula Almeida Universidade de Passo Fundo
  • Vitória Menin Universidade de Passo Fundo
  • Daniel Lima Dalla Lana Universidade de Passo Fundo
  • Ana Paula Farina Universidade de Passo Fundo
  • Doglas Cecchin Universidade de Passo Fundo
Keywords: Calcium hypochlorite, Passive ultrasonic irrigation, Pulp dissolution, Sodium hypochlorite


Objectives: To compare, in vitro, the effectiveness of calcium hypochlorite and sodium hypochlorite associated with passive ultrasonic irrigation (PUI) on pulpal tissue dissolution.
Methods: The pulp tissue of forty-five bovine incisors was removed and each complete pulp was divided into two pieces of similar volume, resulting in 90 pieces distributed into nine groups (n=10), according to dissolution procedure: G1: distilled water; G2: 2.5% NaOCl; G3: 5.25% NaOCl; G4: 2.5% Ca(OCl)2; G5: 5.25% Ca(OCl)2; G6: 2.5% NaOCl+PUI; G7: 5.25% NaOCl+PUI; G8: 2.5%
Ca(OCl)2+PUI and G9: 5.25% Ca(OCl)2+PUI. Each sample was weighed on a high precision balance before and after the dissolution procedure. The differences in weights were calculated and the mean percentage loss was determined. The data were statistically analyzed using two-way ANOVA and Games-Howel tests at 5% significance level.
Results: Group 5 (5.25% Ca(OCl)2), 6 (2.5% NaOCl+PUI), 7 (5.25% NaOCl+PUI), 8 (2.5% Ca(OCl)2+PUI) and 9 (5.25% Ca(OCl)2+PUI) showed the highest mean percentages of weight reduction when compared to other groups (p<0.001). However, there was no statistically significant difference between them (p<0.001).
Conclusions: Ca(OCl)2 and PUI contributes significantly to dissolution of pulp tissue.


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;35:493-502. https://doi.org/10.1016/j. joen.2008.12.014

Peters OA, Laib A, Göhring TN, et al. Changes in root canal geometry after preparation assessed by high-resolution computed tomography. J Endod. 2001;27:1-6. https://doi.org/10.1097/00004770-200101000-00001

Siqueira J, Batista M, Fraga R, et al. Antibacterial effects of endodontic irrigants on black-pigmented gram-negative anaerobes and facultative bacteria. J Endod. 1998;24:414-6. https://doi.org/10.1016/S0099- 2399(98)80023-X

Niazi SA, Clark D, Do T, et al. The effectiveness of enzymic irrigation in removing a nutrient-stressed endodontic multispecies biofilm. Int Endod J 2014;47:756-68. https://doi.org/10.1111/iej.12214

Du T, Wang Z, Shen Y, et al. Effect of long-term exposure to endodontic disinfecting solutions on young and old Enterococcus faecalis biofilms in dentin canals. J Endod. 2014;40:509-14. https://doi.org/10.1016/j. joen.2013.11.026

Okino LA, Siqueira EL, Santos M, et al. Dissolution of pulp tissue by aqueous solution of chlorhexidine digluconate and chlorhexidine digluconate gel. Int Endod J. 2004;37:38-41. https://doi.org/10.1111/ j.1365-2591.2004.00749.x

Tanomaru-Filho M, Leonardo MR, Silva LA, et al. Inflammatory response to different endodontic irrigating solutions. Int Endod J. 2002;35:735-9. https://doi.org/10.1046/j.1365-2591.2002.00544.x

Moreira DM, Almeida JFA, Ferraz CCR, et al. Structural analysis of bovine root dentin after use of different endodontics auxiliary chemical substances. J Endod. 2009;35:1023-7. https://doi.org/10.1016/j. joen.2009.04.002

Santos JN, Carrilho MR, De Goes MF, et al. Effect of chemical irrigants on the bond strength of a self-etching adhesive to pulp chamber dentin. J Endod. 2006;32:1088-90. https://doi.org/10.1016/j.joen.2006.07.001

Farina AP, Cecchin D, Barbizam JV, et al. Influence of endodontic irrigants on bond strength of a self-etching adhesive. Aust Endod J. 2011;37:26-30. https://doi.org/10.1111/j.1747-4477.2010.00249.x

Whittaker HA, Mohler BM. The sterilisation of milk bottles with calcium hypochlorite. Am J Public Health (NY). 1912;2:282-7. https://doi. org/10.2105/AJPH.2.4.282

Twomey JO, Abdelaziz KM, Combe EC, et al. Calcium hypochlorite as a disinfecting additive for dental stone. J Prosthet Dent. 2003;90:282–8. https://doi.org/10.1016/S0022-3913(03)00412-8

Buchholz A, Matthews KR. Reduction of Salmonella on alfalfa seeds using peroxyacetic acid and a commercial seed washer is as effective as treatment with 20 000 ppm of Ca(OCl)2. Lett Appl Microbiol. 2010;51: 462-8. https://doi.org/10.1111/j.1472-765X.2010.02929.x

de Almeida AP, Souza MA, Miyagaki DC, et al. Comparative evaluation of calcium hypochlorite and sodium hypochlorite associated with passive ultrasonic irrigation on antimicrobial activity of a root canal system infected with Enterococcus faecalis: an in vitro study. J Endod. 2014;40: 1953-7. https://doi.org/10.1016/j.joen.2014.08.025

Dutta A, Saunders WP. Comparative evaluation of calcium hypochlorite and sodium hypochlorite on soft-tissue dissolution. J Endod. 2012;38: 1395-8. https://doi.org/10.1016/j.joen.2012.06.020

Moorer WR, Wesselink PR. Factors promoting the tissue dissolving capability of sodium hypochlorite. Int Endod J. 1982;15:187-96. https://


Stojicic S, Zivkovic S, Qian W, et al. Tissue dissolution by sodium hypochlorite: effect of concentration, temperature, agitation, and surfactant. J Endod. 2010;36:1558-62. https://doi.org/10.1016/j. joen.2010.06.021

Plotino G, Pameijer C, Grande NM, et al. Ultrasonics in endodontics: a review of the literature. J Endod. 2007;33:81-95. https://doi.org/10.1016/j.joen.2006.10.008

Grundling GL, Zechin JG, Jarduim WM, et al. Effect of ultrasonics on Enterococcus faecalis biofilm in a bovine tooth model. J Endod. 2011;37;1128-33. https://doi.org/10.1016/j.joen.2011.05.006

Grossman LI, Meiman B. Solution of pulp tissue by chemical agents. J Am Dent Assoc. 1941;28:223-5. https://doi.org/10.14219/jada. archive.1941.0060

Koskinen KP, Stenvall H, Uitto VJ. Dissolution of bovine pulp tissue by endodontic solutions. Scand J Dent Res. 1980;88:406-11. https://doi. org/10.1111/j.1600-0722.1980.tb01246.x

Beltz RE, Torabinejad M, Pouresmail M. Quantitative analysis of the solubilizing action of MTAD, sodium hypochlorite, and EDTA on bovine pulp and dentin. J Endod. 2003;29:334-7. https://doi.org/10.1097/00004770- 200305000-00004

Jungbluth H, Peters C, Peters O, et al. Physicochemical and pulp tissue dissolution properties of some household bleach brands compared with a dental sodium hypochlorite solution. J Endod. 2012;38:372-5. https:// doi.org/10.1016/j.joen.2011.12.013

Slutzky-Goldberg I, Hanut A, Matalon S, et al. The effect of dentin on the pulp tissue dissolution capacity of sodium hypochlorite and calcium hydroxide. J Endod. 2013;39:980-3. https://doi.org/10.1016/j.joen.2013.04.040

Nakamura H, Asai K, Fujita H, et al. The solvent action of sodium hypochlorite on bovine tendon collagen, bovine pulp, and bovine gingiva. Oral Surg Oral Med Oral Pathol. 1985;60:322-6. https://doi. org/10.1016/0030-4220(85)90317-2

Abou-Rass M, Oglesby SW. The effects of temperature, concentration, and tissue type on the solvent ability of sodium hypochlorite. J Endod. 1981;7:376-7. https://doi.org/10.1016/S0099-2399(81)80059-3

Clarkson RM, Moule AJ, Podlich H, et al. Dissolution of porcine incisor pulps in sodium hypochlorite solutions of varying compositions and concentrations. Aust Dent J. 2006;51:245-51. https://doi. org/10.1111/j.1834-7819.2006.tb00437.x

Estrela C, Estrela CR, Barbin EL, et al. Mechanism of action of sodium hypochlorite. Braz Dent J. 2002;13:113-7. ttps://doi.org/10.1590/S0103-64402002000200007

Van der Sluis LWM, Versluis M, Wu MK, et al. Passive ultrasonic irrigation of the root canal: a review of the literature. Int Endod J. 2007;40:415-26. https://doi.org/10.1111/j.1365-2591.2007.01243.x

Paiva SS, Siqueira-Júnior JF, Rôças IN, et al. Supplementing the antimicrobial effects of chemomechanical debridement with either passive ultrasonic irrigation or a final rinse with chlorhexidine: a clinical study. J Endod. 2012;38:38-9. https://doi.org/10.1016/j.joen.2012.06.023

Bhuva B, Patel S, Wilson R, et al. The effectiveness of passive ultrasonic irrigation on intraradicular Enterococcus faecalis biofilms in extracted single-rooted human teeth. Int Endod J. 2010;43:241-50. https://doi. org/10.1111/j.1365-2591.2009.01672.x

Huffaker SK, Safavi K, Spangberg LS, et al. Influence of a passive sonic irrigation system on the elimination of bacteria from root canal systems: a clinical study. J Endod. 2010;36:1315-8. https://doi.org/10.1016/j. joen.2010.04.024

Zehnder M, Kosicki D, Luder H, et al. Tissue-dissolving capacity and antibacterial effect of buffered and unbuffered hypochlorite solutions. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2002;94:756-62. https:// doi.org/10.1067/moe.2002.128961

Irala LE, Grazziotin-Soares R, Salles AA, et al. Dissolution of bovine pulp tissue in solutions consisting of varying NaOCl concentrations and combined with EDTA. Braz Oral Res. 2010;24:271-6. https://doi. org/10.1590/S1806-83242010000300003

Ordinola-Zapata R, Bramante CM, Aprecio RM, et al. Biofilm removal by 6% sodium hypochlorite activated by different irrigation techniques. Int Endod J. 2014;47:659-66. https://doi.org/10.1111/iej.12202

Thomas AR, Velmurugan N, Smita S, et al. Comparative evaluation of canal isthmus debridement efficacy of modified endovac technique with different irrigation systems. J Endod. 2014;40:1676-80. https://doi.org/10.1016/j. joen.2014.05.014.

Original Article