Antibacterial Efficacy of Irrigants with Varying Osmolarity on E. faecalis Biofilm: An In Vitro Study

AIM

To evaluate the role of the addition of different concentrations of sodium chloride salt to conventional intracanal irrigants to vary their osmotic values and thereby compare their antibacterial efficacy.

MATERIALS AND METHODS

In an active attachment biofilm model, Enterococcus faecalis (ATCC 29212) biofilms were grown. Sodium chloride salts were added to 100 mL of distilled water to make 6M (hyperosmotic), 0.5M, and 0.25M (hypoosmotic) sodium chloride solutions, respectively. The experimental groups were divided into three groups: Group I: 5.25% sodium hypochlorite, group II: 2% chlorhexidine, and group III: 2% povidone iodine, and four subgroups within these three groups, such as subgroup A (without salt solution), subgroup B (with 6M of hyperosmotic salt solution), subgroup C (with 0.5M of hypoosmotic salt solution), and subgroup D (with 0.25M of hypoosmotic salt solution), respectively. Biofilms were treated with all the subgroups for a contact time of 15 min. A crystal violet assay was done to estimate the bacterial cell biomass.

RESULTS

The results revealed that subgroups IIIB, IB, and IID, ID had a statistical reduction in bacterial biomass at p < 0.05. There were no significant differences between subgroups IC, IIC, and IIIC and subgroups IA, IIA, and IIIA.

CONCLUSION

The antibacterial efficacy of all three irrigants was significantly affected by varying the osmolarities.

CLINICAL SIGNIFICANCE

The results prove that the hyperosmotic and hypoosmotic salt solutions, along with irrigants, have enhanced antibacterial efficacy on E. faecalis biofilm due to its ability to vary the turgor pressure of cell wall, as well as the inherent properties of the irrigants such as hypochlorous acid formation, ionic interaction, and free radical interactions.

Comparative Evaluation of the Effects of Calcium Hydroxide Intracanal Medicament and Antibiotic Paste on Dentin Microhardness: A Systematic Review

An infectious environment is reported to hinder the process of pulp tissue regeneration by damaging the cells responsible for tissue formation, including stem cells in the periapical tissues. Therefore, a sterile environment is critical for pulp tissue regeneration, which can be achieved by copious irrigation and intracanal medicament (ICM) placement. This systematic review compares the effect of calcium hydroxide (Ca(OH)2) and various antibiotic pastes, such as triple antibiotic paste (TAP), modified triple antibiotic paste (MTAP), and double antibiotic paste (DAP), on dentin microhardness when used as ICMs. MeSH terms and specific keywords were used to search Scopus, EBSCOhost, Cochrane Library, and PubMed. In vitro studies that compared the impact of Ca(OH)2 and antibiotic pastes, such as TAP, MTAP, and DAP, on dentin microhardness were included. Data from the included articles were extracted, and their quality was assessed using the revised Quality Assessment Tool for In Vitro Studies (QUIN) tool. Seven articles were included for the qualitative synthesis, and data were extracted from each. Within the scope of this systematic review, Ca(OH)2, an alternative ICM recommended by the American Association of Endodontics Glossary of Endodontic Terms for REPs, showed a lesser reduction in microhardness than TAP. DAP and MTAP caused a reduction in dentin microhardness compared to that of Ca(OH)2.