Neutralized ECAS Shows Strong Results in Fighting Biofilm in Dental Unit Waterlines
A new study found that neutralized electrolyzed chlorinated water solution (ECAS) effectively reduced planktonic bacteria and disrupted biofilm in contaminated dental unit waterlines. By combining shock and continuous treatment, ECAS demonstrated promising potential as a safer, lower-chlorine alternative to sodium hypochlorite.
Since Blake first identified contaminated dental unit waterlines (DUWLs) in 1963, concerns about microbial safety have persisted. Research has shown that bacterial counts can exceed 200,000 CFU/mL within just 5 days if untreated, far above the 500 CFU/mL threshold recommended by the American Dental Association (ADA) and United States Centers for Disease Control and Prevention (CDC). Despite decades of chemical treatment strategies, biofilm remains a persistent challenge, and occasional infection cases have underscored the importance of effective waterline management.
In a study published in the Journal of the American Dental Association, researchers evaluated neutralized electrolyzed chlorinated water solution (ECAS) as an alternative to sodium hypochlorite for managing DUWL contamination. ECAS, a chlorine-based disinfectant with a neutral pH, is composed mainly of hypochlorous acid. Unlike harsher chemical agents, ECAS is environmentally compatible, safe for tissues, and reverts to regular water after use. It has demonstrated broad microbicidal activity against bacteria, yeast, and fungi while minimizing toxicity and irritation.
Two treatment protocols were tested: Group A received periodic shock treatments with concentrated ECAS followed by daily maintenance using diluted ECAS, while Group B received more frequent shock treatments. Both approaches effectively lowered bacterial counts, but Group B consistently achieved ADA and CDC standards more quickly and maintained compliance over the study period. Scanning electron microscopy confirmed that ECAS not only reduced planktonic bacteria but also disrupted established biofilm structures, making them more vulnerable to ongoing treatment.
Importantly, ECAS achieved these results with chlorine levels significantly lower than those typically recommended with sodium hypochlorite, reducing the risk of equipment corrosion and enhancing safety. While long-term effects on older dental units require further study, ECAS demonstrated strong resistance compatibility with materials like stainless steel and copper.
These findings suggest that neutralized ECAS can be an effective and practical solution for dental practices struggling with DUWL contamination, especially in units where biofilm has proven resistant to traditional disinfectants. By combining shock and maintenance treatments, ECAS not only reduces bacterial load but also inhibits biofilm regrowth, supporting safer delivery of care. Click here to read more.
