Evaluation of the antimicrobial efficacy of different concentrations of a novel root canal filling material for primary teeth ‑ An in vitro study

Abstract

Background: The demand for an ideal root canal filling material in primary teeth with maximum
antibacterial properties keeps escalating to improve the success rate of root canal treatment in
primary teeth. Hence, the present study was conducted to determine the antimicrobial efficacy of
the different concentrations of a novel root canal filling material.
Materials and Methods: An in vitro study was designed to compare the antimicrobial efficacy of
different concentrations of the novel obturating material for primary teeth. Different concentrations
of the novel obturating material were prepared using calcium hydroxide, zinc oxide cement, and
metronidazole and were tested for its antimicrobial efficacy against Streptococcus mutans and
Enterococcus faecalis using Mueller–Hinton Agar for 24 h at 37°C. The zone of inhibition was measured
in millimeters after 24 h. The values were entered into a Microsoft Excel spreadsheet and subjected
to statistical analysis. Descriptive statistics were used for data summarization and presentation.
Friedman test and Kruskal–Wallis test were used to compare the different concentrations of the
novel obturating materials against S. mutans and E. faecalis. P < 0.05 was considered to be significant.
Results: Against S. mutans at 1% concentration, the zone of inhibition was statistically greater at
50 μl and at 2% and 3%, the zone of inhibition was greater at 100 μl. Similarly, against E. faecalis,
the zone of inhibition was statistically greater at 100 μl at 2% and no significant difference was
noted at 1% and 3%. Comparison between the groups at 25, 50, and 100 μl shows no significant
difference against S. mutans between 1%, 2%, and 3% of 60–40 concentration. However, 3% 60–40
concentration at 50 μl shows significantly increased zone of inhibition against E. faecalis.
Conclusion: Two percentage metronidazole at 60–40 (calcium hydroxide–zinc oxide) concentration
of the novel obturating material at 100 μl has better antibacterial properties against both S. mutans
and E. faecalis.
Key Words: Child, deciduous, in vitro techniques, microbiology, pulpectomy, tooth