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. 2022 May 9;12(1):7595.
doi: 10.1038/s41598-022-11780-x.

Effect of calcium hydroxide on morphology and physicochemical properties of Enterococcus faecalis biofilm

Mahere Momenijavid  1 , Himen Salimizand  2 , Aazam Korani  3 , Omid Dianat  4 , Bijan Nouri  5   6 , Rashid Ramazanzadeh  2 , Amjad Ahmadi  7 , Jino Rostamipour  1 , Mohammad Rastegar Khosravi  8
Affiliations

Effect of calcium hydroxide on morphology and physicochemical properties of Enterococcus faecalis biofilm

Mahere Momenijavid et al. Sci Rep. .

Abstract

Calcium hydroxide Ca(OH)2 has been used as an intracanal medicament to targets microbial biofilms and avert secondary infection in the root canal system. This study evaluated the effects of this material on the morphology and physicochemical properties of an established in-vitro biofilm of Enterococcus faecalis. A biofilm of E. faecalis was grown in multichannel plates. The chemicals including Ca2+, OH-, and saturated Ca(OH)2 (ie 21.6 mM) were prepared in order to evaluate which component eradicated or amplified biofilm structure. Various biochemical and microscopic methods were used to investigate the properties of the biofilm. Biofilms treated with Ca(OH)2 absorbed more Ca2+ because of the alkaline pH of the environment and the ions affected the physicochemical properties of the E. faecalis biofilm. A denser biofilm with more cavities and a granular surface was observed in the presence of Ca2+ ions. This resulted in a decrease in the surface-to-biofilm ratio with increases in its biomass, thickness, colony size, and volume. Calcium hydroxide did not destroy E. faecalis biofilms but rather contributed to the biofilm structure. This in-vitro study sheds light on a missing link in the formation of E. faecalis biofilm in which the Ca2+ in Ca(OH)2.

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Conflict of interest statement

The authors declare no competing interests.

Figures

Figure 1
Figure 1
SEM images of E. faecalis mature biofilm treated with (a), Ca(OH)2; (b), Ca2+; (c), OH- for 7 days. The control group, d, was original biofilm without any treatment. The scale bar is 1 µm.
Figure 2
Figure 2
CLSM images of 21-day biofilm of E. faecalis that had been treated with solutions for 7 days. The control group was not treated with chemicals. (A), control group; (B), Ca(OH)2; (C), Ca2+; D, OH-.
Figure 3
Figure 3
Calculated amount of CLSM parameters and related P value. (A) Maximum thickness; (B) Average thickness; (C) Colony volume; (D) Biomass; (E), Average colony size; (F), Surface to biomass ratio. Significant token: *, 0.05; **, 0.01; ***, 0.001; ****, 0.0001. No significant results were not illustrated.
Figure 4
Figure 4
AFM images of a 21-day biofilm of E. faecalis after 7 days under different solutions, at a scale of 10 µm2. (a) control (43.4); (b) Ca(OH)2 (52.6); (c) Ca2+ (56.7); (d) OH-(42).
Figure 5
Figure 5
Light microscopy images of stained 21-day biofilm polysaccharides of E. faecalis after 7 days of contact with solutions. (a), Control, no solution; (b), Ca(OH)2; (c), Ca2+; (d), OH-.
Figure 6
Figure 6
Measured polysaccharide concentrations by groups. Significance token: *, 0.05; **, 0.01; ***, 0.001; Non-significant results are not shown.
Figure 7
Figure 7
Ca2+ concentration of biofilm in different groups (P < 0.05). Significance: *, 0.05; **, 0.01; ***, 0.001; ****, 0.0001. Non-significant results are not shown.
Figure 8
Figure 8
Quantitation of viable cells under different solutions. Abbreviations: Negative control, NC; Positive control, PC.
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References

    1. Georgiou AC, Crielaard W, Armenis I, de Vries R, van der Waal SV. Apical periodontitis is associated with elevated concentrations of inflammatory mediators in peripheral blood: A systematic review and meta-analysis. J. Endod. 2019;45:1279–1295.e1273. doi: 10.1016/j.joen.2019.07.017. - DOI - PubMed
    1. Ørstavik D. Endodontic treatment of apical periodontitis. Essen. Endodontol. 2019 doi: 10.1002/9781119272014.ch11. - DOI
    1. Haapasalo M, Endal U, Zandi H, Coil JM. Eradication of endodontic infection by instrumentation and irrigation solutions. Endod. Top. 2005;10:77–102. doi: 10.1111/j.1601-1546.2005.00135.x. - DOI
    1. Ricucci D, Siqueira JF. Biofilms and apical periodontitis: Study of prevalence and association with clinical and histopathologic findings. J. Endodon. 2010;36:1277–1288. doi: 10.1016/j.joen.2010.04.007. - DOI - PubMed
    1. van der Waal SV, et al. The effects of hyperosmosis or high pH on a dual-species biofilm of Enterococcus faecalis and Pseudomonas aeruginosa: an in vitro study. Int. Endod. J. 2011;44:1110–1117. doi: 10.1111/j.1365-2591.2011.01929.x. - DOI - PubMed

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