Introduction: Modifications in the mechanical properties of dentin may reduce the fracture resistance of tooth, especially after endodontic treatment. The aim of present study was to evaluate the effect of the irrigation with different root canal irrigants on the microhardness of root dentin. Methods: The coronal portion of 60 single-rooted bovine incisors was sectioned and the pulpal tissue removed using endodontic K-files. The roots were cut transversely to obtain 2 fragments, which were embedded in acrylic resin and randomly distributed into six groups (n=20) according to the irrigation protocol: distilled water (DW) (control); 2% chlorhexidine solution (CHX); 6% sodium hypochlorite (NaOCl); 6% calcium hypochlorite (Ca[OCl]2); QMix; and 6.5% grape seed extract solution (GSE). The solutions were kept in contact with the root dentin specimens for 30 min. After that, irrigation with 5 mL of DW was performed. The Vickers microhardness was determined by performing three indentations in all specimens, using 300-g load and 20-second dwell time. The first indentation was made 1.000 µm from the root canal entrance, and two other indentations were made at a distance of 200 µm from each other. The microhardness value for each specimen was obtained as the average of the results for the three indentations. Data were statistically analyzed using one-way ANOVA with 5% significance level. Results: All the tested irrigant solutions maintained the same microhardness level of the root dentin when compared to the control group, with no statistically significant differences between them (p<0.05) Conclusion: The tested irrigant solutions did not present ability to modify the microhardness of root dentin.
Kakehashi S, Stanley HR, Fitzgerald RJ. The effects of surgical exposures of dental pulps in germ-free and conventional laboratory rats. Oral Surg Oral Med Oral Pathol. 1965 Sep;20:340-9.
Du T, Wang Z, Shen Y, Ma J, Cao Y, Haapasalo M. Effect of long-term exposure to endodontic disinfecting solutions on young and old Enterococcus faecalis biofilms in dentin canals. J Endod. 2014 Apr;40(4):509-14. doi: 10.1016/j.joen.2013.11.026.
Okino LA, Siqueira EL, Santos M, Bombana AC, Figueiredo JA. Dissolution of pulp tissue by aqueous solution of chlorhexidine digluconate and chlorhexidine digluconate gel. Int Endod J. 2004 Jan;37(1):38-41.
Moreira DM, Almeida JF, Ferraz CC, Gomes BP, Line SR, Zaia AA. Structural analysis of bovine root dentin after use of different endodontics auxiliary chemical substances. J Endod. 2009 Jul;35(7):1023-7. doi: 10.1016/j.joen.2009.04.002.
Marending M, Paqué F, Fischer J, Zehnder M. Impact of irrigant sequence on mechanical properties of human root dentin. J Endod. 2007 Nov;33(11):1325-8.
Patil CR, Uppin V. Effect of endodontic irrigating solutions on the microhardness and roughness of root canal dentin: an in vitro study. Indian J Dent Res. 2011 Jan-Feb;22(1):22-7. doi: 10.4103/0970-9290.79969.
Aslantas EE, Buzoglu HD, Altundasar E, Serper A. Effect of EDTA, sodium hypochlorite, and chlorhexidine gluconate with or without surface modifiers on dentin microhardness. J Endod. 2014 Jun;40(6):876-9. doi: 10.1016/j.joen.2013.10.041.
Ferraz CC, Gomes BP, Zaia AA, Teixeira FB, Souza-Filho FJ. In vitro assessment of the antimicrobial action and the mechanical ability of chlorhexidine gel as an endodontic irrigant. J Endod. 2001 Jul;27(7):452-5.
Böttcher DE, Sehnem NT, Montagner F, Fatturi Parolo CC, Grecca FS. Evaluation of the effect of Enterococcus faecalis biofilm on the 2% chlorhexidine substantivity: an in vitro study. J Endod. 2015 Aug;41(8):1364-70. doi: 10.1016/j.joen.2015.04.016.
Oliveira LD, Carvalho CA, Nunes W, Valera MC, Camargo CH, Jorge AO. Effects of chlorhexidine and sodium hypochlorite on the microhardness of root canal dentin. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2007 Oct;104(4):e125-8.
Stojicic S, Shen Y, Qian W, Johnson B, Haapasalo M. Antibacterial and smear layer removal ability of a novel irrigant, QMiX. nt Endod J. 2012 Apr;45(4):363-71. doi: 10.1111/j.1365-2591.2011.01985.x.
Saghiri MA, Delvarani A, Mehrvarzfar P, Malganji G, Lotfi M, Dadresanfar B, et al. A study of the relation between erosion and microhardness of root canal dentin. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2009 Dec;108(6):e29-34. doi: 10.1016/j.tripleo.2009.07.056.
Giardino L, Ambu E, Becce C, Rimondini L, Morra M. Surface tension comparison of four common root canal irrigants and two new irrigants containing antibiotic. J Endod 2006 Nov;32(11):1091-3.
de Almeida AP, Souza MA, Miyagaki DC, Dal Bello Y, Cecchin D, Farina AP. 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 Dec;40(12):1953-7. doi: 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 Oct;38(10):1395-8. doi: 10.1016/j.joen.2012.06.020.
Leonardo NG e S, Carlotto IB, Luisi SB, Kopper PMP, Grecca FS, Montagner F. Calcium Hypochlorite Solutions: Evaluation of Surface Tension and Effect of Different Storage Conditions and Time Periods over pH and Available Chlorine Content. J Endod. 2016 Apr;42(4):641-5. doi: 10.1016/j.joen.2016.01.006.
Blattes GBF, Mestieri LB, Böttcher DE, Fossati ACM, Montagner F, Grecca FS. Cell migration, viability and tissue reaction of calcium hypochlorite based-solutions irrigants: an in vitro and in vivo study. Arch Oral Biol. 2017 Jan;73:34-39. doi: 10.1016/j.archoralbio.2016.08.037.
Cecchin D, Farina AP, Souza MA, Albarello LL, Schneider AP, Vidal CM, et al. Evaluation of antimicrobial effectiveness and dentine mechanical properties after use of chemical and natural auxiliary irrigants. J Dent. 2015 Jun;43(6):695-702. doi: 10.1016/j.jdent.2015.03.013.
Aguiar TR, Vidal CM, Phansalkar RS, Todorova I, Napolitano JG, McAlpine JB, et al. Dentin biomodification potential depends on polyphenol source. J Dent Res. 2014 Apr;93(4):417-22. doi: 10.1177/0022034514523783.
Ørstavik D, Haapasalo M. Disinfection by endodontic irrigants and dressings of experimentally infected dentinal tubules. Endod Dent Traumatol. 1990 Aug;6(4):142-9.
Arends J, Ten Bosch JJ. Demineralization and remineralization evaluation techniques. J Dent Res. 1992 Apr;71 Spec No:924-8.
Panighi M, G’Sell C. Influence of calcium concentration on the dentin wettability by an adhesive. J Biomed Mater Res. 1992 Aug;26(8):1081-9.
Cruz-Filho AM, Sousa-Neto MD, Savioli RN, Silva RG, Vansan LP, Pécora JD. Effect of chelating solutions on the microhardness of root canal lumen dentin. J Endod. 2011 Mar;37(3):358-62. doi: 10.1016/j.joen.2010.12.001.
Pashley D, Okabe A, Parham P. The relationship between dentin microhardness and tubule density. Endod Dent Traumatol. 1985 Oct;1(5):176-9.
Zhang K, Kim YK, Cadenaro M, Bryan TE, Sidow SJ, Loushine RJ, et al. Effects of different exposure times and concentrations of sodium hypochlorite/ethylenediaminetetraacetic acid on the structural integrity of mineralized dentin. J Endod. 2010 Jan;36(1):105-9. doi: 10.1016/j.joen.2009.10.020.
De Deus G, Reis C, Fidel S, Fidel R, Paciornik S. Dentine demineralization when subjected to BioPure MTAD: a longitudinal and quantitative assessment. J Endod. 2007 Nov;33(11):1364-8.
Ari H, Erdemir A, Belli S. Evaluation of the effect of endodontic irrigation solution on microhardness and the roughness of root canal dentin. J Endod. 2004 Nov;30(11):792-5.
Doğan H, Qalt S. Effects of chelating agents and sodium hypochlorite on mineral content of root dentin. J Endod. 2001 Sep;27(9):578-80.
Breschi L, Mazzoni A, Nato F, Carrilho M, Visintini E, Tjäderhane L, et al. Chlorhexidine stabilizes the adhesive interface: a 2-year in vitro study. Dent Mater. 2010 Apr;26(4):320-5. doi: 10.1016/j.dental.2009.11.153.
Cecchin D, Soares Giaretta V, Granella Cadorin B, Albino Souza M, Vidal CMP, Paula Farina A. Effect of synthetic and natural-derived novel endodontic irrigant solutions on mechanical properties of human dentin. J Mater Sci Mater Med. 2017 Aug 17;28(9):141. doi: 10.1007/s10856-017-5960-1.
Ballal NV, Tweeny A, Khechen K, Prabhu KN, Satyanarayan, Tay FR. Wettability of root canal sealers on intraradicular dentine treated with different irrigating solutions. J Dent. 2013 Jun;41(6):556-60. doi: 10.1016/j.jdent.2013.04.005.
Abou-Rass M, Patonai FJ Jr. The effects of decreasing surface tension on the flow of irrigating solutions in narrow root canals. Oral Surg Oral Med Oral Pathol. 1982 May;53(5):524-6.
Bedran-Russo AK, Pauli GF, Chen SN, McAlpine J, Castellan CS, Phansalkar RS, et al. Dentin biomodification: strategies, renewable resources and clinical applications. Dent Mater. 2014 Jan;30(1):62-76. doi: 10.1016/j.dental.2013.10.012.
The Brazilian Journal of Oral Sciences uses the Creative Commons license (CC), thus preserving the integrity of the articles in an open access environment.