Hypochlorite solution for root canal irrigation that lacks a chlorinated odor

ABSTRACT

Objectives: This is an in vitro study to develop a formulation of a hypochlorite solution for root canal irrigation that lacks a chlorinated odor. The antibacterial effect, tissue dissolution efficacy, and the cytotoxicity of the solution were assessed in cell culture and were compared with those of commercial sodium hypochlorite (NaOCl) solutions. Materials and Methods: Trichloroisocyanuric acid (TCA) was used as the source of hypochlorite ions in solution. All required properties of the NaOCl irrigant were evaluated and compared with those of original 2.5% NaOCl solutions currently in use. Results: Our results revealed that a TCA 3.5% + 1/6 Buffer-1 solution passed the short-term stability test. Moreover, no odor of chlorine gas was detected by three independent observers. The hypochlorite ion content and pH were stable over an incubation period of 4 weeks. The new solution did not differ from commercial products in terms of the dissolution property on bovine pulpal tissue (P > 0.05). Moreover, the antibacterial effect of this solution on Enterococcus faecalis did not differ from that of the commercial products (P > 0.05). In addition, our biocompatibility analysis demonstrated no difference among the tested solutions (P > 0.05). Conclusions: According to the results of all properties tested, TCA 3.5% + 1/6 Buffer-1 could be considered an option for NaOCl irrigation with the benefit of no detectable chlorine odor.

Key words:

Hypochlorite solution - lacks a chlorinated odor - root canal irrigant

• REFERENCES

• 1 Basvanis B, Haapasalo M. Update on endodontic irrigating solutions. Endod Topics 2012; 24: 74-102
• 2 Byström A, Sundqvist G. Bacteriologic evaluation of the efficacy of mechanical root canal instrumentation in endodontic therapy. Scand J Dent Res 1981; 89: 321-8
• 3 Byström A, Sundqvist G. Bacteriologic evaluation of the effect of 0.5 percent sodium hypochlorite in endodontic therapy. Oral Surg Oral Med Oral Pathol 1983; 55: 307-12
• 4 Bystrom A, Sundqvist G. The antibacterial action of sodium hypochlorite and EDTA in 60 cases of endodontic therapy. Int Endod J 1985; 18: 35-40
• 5 Podar R, Kulkarni GP, Dadu SS, Singh S, Singh SH. In vivo antimicrobial efficacy of 6% Morinda citrifolia, Azadirachta indica, and 3% sodium hypochlorite as root canal irrigants. Eur J Dent 2015; 9: 529-34
• 6 Goztas Z, Onat H, Tosun G, Sener Y, Hadimli HH. Antimicrobial effect of ozonated water, sodium hypochlorite and chlorhexidine gluconate in primary molar root canals. Eur J Dent 2014; 8: 469-74
• 7 Siqueira Jr JF, Rôças IN, Favieri A, Lima KC. Chemomechanical reduction of the bacterial population in the root canal after instrumentation and irrigation with 1%, 2.5%, and 5.25% sodium hypochlorite. J Endod 2000; 26: 331-4
• 8 Vajrabhaya L, Sangalungkan V, Kamolroongwarakul R, Apai W, Limmechongchai S, Yingtanothai M. Five EDTA formulae in smear layer removed in canal instrumentation. J Dent Assoc Thai 2004; 54: 112-220
• 9 Estrela C, Estrela CR, Barbin EL, Spanó JC, Marchesan MA, Pécora JD. Mechanism of action of sodium hypochlorite. Braz Dent J 2002; 13: 113-7
• 10 International Organization for Standardization. Dentistry-evaluation of Biocompatibility of Medical Device Used in Dentistry ISO 7405:2008. Geneva: International Organization for Standardization (ISO); 2008
• 11 International Organization for Standardization. Biological evaluation of medical devices – Part 5: Tests for In vitro cytotoxicity. ISO 10993-5:2009. Geneva: International Organization for Standardization (ISO); 2009
• 12 Koskinen KP, Meurman JH, Stenvall H. Appearance of chemically treated root canal walls in the scanning electron microscope. Scand J Dent Res 1980; 88: 505-12
• 13 Moore WR, Wesselink PR. Factors promoting the tissue dissolving capacity of sodium hypochlorite. Int Endod J 1981; 15: 187-96
• 14 Mehra P, Clancy C, Wu J. Formation of a facial hematoma during endodontic therapy. J Am Dent Assoc 2000; 131: 67-71