In Vitro Study to Evaluate the Antibacterial Effect of an Oxidising Agent on Ex Vivo Biofilm

TL;DR

This study tested how well two oxidizing agents in mouth rinses can kill bacteria in dental biofilms compared to a salt solution and a standard antibacterial rinse.

Contribution

The study introduces two oxidizing agent-based mouth rinses and demonstrates their antibacterial efficacy in an ex vivo model.

Findings

BMmr and BMfl significantly reduced biofilm vitality compared to NaCl.

BMmr and BMfl showed antibacterial effects similar to chlorhexidine.

The results suggest oxidizing agents may be effective alternatives to traditional mouth rinses.

Abstract

To evaluate the antibacterial effect of a mouthrinse and a fluid, both containing an oxidising agent, compared with saline (negative control) and chlorhexidine (0.2%, positive control), after application to 24-hour-old biofilms.

After 24 participants had refrained from all oral hygiene measures for a period of 24 h, a voluminous biofilm sample was taken from the buccal sites of molars, smeared on a microscope slide and divided into four parts. The four samples were each coated with 5 µl of a mouth rinse solution (BMmr, blueM mouth rinsing solution, NL), a fluid (BMfl, blueM oxygen fluid, NL), chlorhexidine 0.2% (CHX) and NaCl. After 1 min, excess liquid was suctioned off, and biofilms were stained with vital fluorescent dyes for 2 min. The stained samples were covered with a cover slip, and four pictures per sample were recorded with a digital camera under the fluorescence microscope. A special image analysis program used the red and green pixels to calculate the percentage of metabolically active bacteria in the entire biofilm sample (dental biofilm vitality, VF%).

Both BMmr and BMfl reduced VF to 18.46 ± 9.59% and 19.53 ± 12.17% significantly (P < 0.001) compared to NaCl, with values of 59.88 ± 10.14%. CHX revealed values of 14.35 ± 6.56%, values that were not significantly lower (P < 0.001) than the other active solutions.

Both BMmr and BMfl demonstrated a statistically significant antibacterial effect compared to NaCl and showed a similar effect to CHX. However, clinical trials are needed to evaluate the efficacy of both products containing oxidising agents when used as oral rinses.

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