In vitro assessment of interaction between lidocaine hydrochloride and sodium hypochlorite on root canal dentin before and after chemomechanical instrumentation procedures

Comparative evaluation of effect of nisin-incorporated ethylenediamine tetraacetic acid and MTAD on endodontic biofilm eradication, smear layer removal, and depth of sealer penetration

OBJECTIVES

To comparatively evaluate the nisin-incorporated ethylenediamine tetraacetic acid (N-EDTA) and MTAD on cytotoxicity, endodontic biofilm eradication potential, smear layer removal ability, and sealer penetration depth.

MATERIALS AND METHODS

N-EDTA was prepared and characterized using high-performance liquid chromatography (HPLC). Minimum inhibitory, minimum bactericidal, and minimum biofilm inhibitory concentration (MBC, MIC, and MBIC) were determined on Enterococcus faecalis (E. faecalis) strain. The cytocompatibility of N-EDTA and MTAD was evaluated using 3,(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT)-based colorimetric assay. Dentin specimens (n = 88 for antibacterial analysis, n = 170 for sealer penetration depth) were prepared and subjected to the classical irrigating strategy and obturation, respectively. The scanning electron microscopic evaluation (SEM) was done for the evaluation of biofilm disruption and smear layer removal. Confocal laser scanning microscopy (CLSM) evaluation was done for determining percentage of bacterial viability and sealer penetration depth. Statistical analysis of one-way ANOVA and Tukey's HSD post hoc tests for bacterial viability and Kruskal-Wallis test and Mann-Whitney test for smear layer removal and depth of penetration were done with the significance level set at p < 0.05.

RESULTS

MTAD and N-EDTA showed cytocompatibility without any statistical differences from each other. For N-EDTA, the MIC and MBC values were 12.5 μg/ml (1:8), and MBIC values were 36 μg/ml. Biofilm disruption and killed bacterial percentage of N-EDTA was statistically higher than MTAD, whereas both the materials showed similar efficacy in the removal of the smear layer and sealer penetration depth.

CONCLUSION

N-EDTA had negligible cytotoxicity with similar smear layer removal ability, sealer penetration, and better antibiofilm potential than MTAD.

CLINICAL RELEVANCE

N-EDTA can serve as a viable alternative endodontic irrigant.

Influence of Lignocaine Hydrochloride with Adrenaline on Free Active Chlorine Content of Sodium Hypochlorite Solution Admixed in Various Proportions

Objective:

Local anaesthetic solution that is commonly employed for supplemental intrapulpal injection (IPI) may routinely come in contact with subsequently used sodium hypochlorite (NaOCl) during endodontic treatment of symptomatic irreversible pulpitis cases. This in vitro study investigated the available free active chlorine (FAC) content of 3% NaOCl after mixing with 2% lignocaine hydrochloride with adrenaline (LA) solution in three different proportions using iodometric titration analysis.

Methods:

Aliquots of 3% NaOCl (control) in different measures (30 mL, 27 mL, 21 mL and 15 mL) served as the effective concentrate of various proportions of NaOCl admixed with the test solutions, i.e., demineralised water (DM) and LA. The mixed aliquots containing NaOCl-DM and NaOCl-LA combination solutions admixed in various proportions (9:1, 7:3 and 1:1 w/v) respectively served as the experimental groups. Iodometric titration was performed to determine the FAC of each independent solution.The results were then evaluated using one-way ANOVA and Tukey’s post hoc analysis to determine the differences between various groups and amongst the individual admixtures. The level of significance was set at P<0.05.

Results:

Inter-group comparisons revealed statistically significant differences (P<0.05) between all the test groups. An intra-group analysis revealed significant differences (P<0.05) in group 2, whereas no differences (P>0.05) were observed in group 3. Further, there was a dose dependent reduction in FAC content in both the experimental groups with lowest FAC values were observed in 1:1 solution admixtures followed by 7:3 and 9:1 proportions.

Conclusion:

There was a significant reduction in NaOCl FAC content when admixed with lignocaine HCl even in small proportions. Hence, adequate measures should be taken to remove the residual LA from the pulpal space, before the use of NaOCl after IPI administration.

Efficient removal of 2,6-xylidine precipitate using different agitation protocols: An in vitro field emission scanning electron microscopic study

Background:

Aim:

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Conclusion: