# The Antimicrobial Effect of a Low-Frequency Square Wave Compared to Chlorhexidine

## TL;DR

This study compares the antibacterial effects of low-frequency electrical stimulation and chlorhexidine for oral hygiene in hospitalized patients.

## Contribution

The study introduces low-frequency square-wave electrical stimulation as a potential non-chemical alternative to chlorhexidine for oral hygiene.

## Key findings

- Electrical stimulation at 5V2H showed better antibacterial efficacy than 0.12% chlorhexidine.
- Chlorhexidine-treated specimens showed minimal bacterial presence and a dose-dependent response.
- Electrical stimulation effectiveness was limited by bacterial re-growth after 4 hours.

## Abstract

Background/Objectives: Oral health is critical for overall health, particularly in hospitalized patients whose weakened physical state can lead to oral changes, such as dry mouth and gingivitis due to anxiety and stress. Neglected oral hygiene can lead to infections and systemic complications. This study aims to evaluate the antibacterial efficacy of low-frequency square-wave positive voltage electrical stimulation compared to chlorhexidine and to assess its potential as a next-generation solution for preventing hospital-acquired infections. Methods: Sixty-three tooth specimens were randomly assigned to seven groups, including various concentrations of chlorhexidine and electrical stimulation with or without brushing. Biofilm formation was induced using saliva from healthy donors and standard strains of Streptococcus mutans and Aggregatibactor actinomycetemcomitans. Bacterial colony-forming units (CFU) and absorbance changes were measured post-treatment. Results: Significant reductions in CFU counts were observed in both the chlorhexidine and electrical stimulation groups compared to the control, with the 5V2H group showing superior antibacterial efficacy over 0.12% chlorhexidine. Chlorhexidine-treated specimens demonstrated a dose-dependent response and minimal bacterial presence, while electrical stimulation showed effectiveness but with re-growth observed after 4 h. Scanning electron microscopy revealed substantial biofilm on untreated and electrically stimulated specimens, whereas chlorhexidine-treated specimens exhibited minimal bacterial presence. Conclusions: Intermittent electrical stimulation shows promise as an alternative to chlorhexidine for oral hygiene management in critical care settings, though an optimization of electrical parameters is necessary for sustained effects. This approach could reduce hospital-acquired infections by providing an effective, non-chemical method for maintaining oral hygiene.