Overview
What is it?
Hypochlorous acid (HOCl) is a mild acid naturally produced by neutrophils as part of the innate immune response. It is available as a stabilized rinse for oral use at concentrations of 0.01–0.02%.
How does it work?
HOCl is a powerful oxidizing agent that penetrates bacterial cell walls and damages proteins, enzymes, and nucleic acids. It is effective against bacteria, fungi, and viruses while being non-toxic to human tissues at physiological concentrations.
When is it commonly used?
Used as a daily mouth rinse for plaque and gingivitis management, as a subgingival irrigant during periodontal therapy, and for management of oral mucositis. Suitable for long-term use due to its biocompatibility.
Mechanism of Action
HOCl is a neutral molecule that easily penetrates microbial cell membranes (unlike the negatively charged hypochlorite ion in bleach). Inside the cell, it oxidizes sulfur-containing amino acids (cysteine, methionine), disrupts iron-sulfur clusters, and damages DNA. This causes rapid bacterial cell death. HOCl is produced naturally by myeloperoxidase in neutrophils, making it an endogenous antimicrobial that oral bacteria have limited resistance mechanisms against.
Organisms Studied
| Organism | Abbr. | Research Finding |
|---|---|---|
| Porphyromonas gingivalis | Pg | HOCl reduces Pg in biofilm models and as a subgingival irrigant. |
| Fusobacterium nucleatum | Fn | Sensitive to HOCl irrigation in periodontal pocket models. |
| Streptococcus mutans | Sm | HOCl reduces Sm biofilm on enamel surfaces. |
| Candida albicans | Ca | Effective against Ca biofilms, including denture stomatitis. |
Evidence Summary
Benefits
- Highly biocompatible — naturally produced by immune cells
- No tooth staining or taste alteration
- Broad-spectrum antimicrobial
- Suitable for long-term use
- No known resistance mechanisms
Limitations
- Limited clinical trial data compared to CHX
- Stability of HOCl solutions can be challenging (degrades with light and heat)
- Less potent than chlorhexidine in some studies
- Standardized protocols are still being developed
Quality of Evidence
Emerging evidence from in vitro studies and small clinical trials. Larger RCTs are needed.
Key Clinical Takeaways
- 1Promising biocompatible alternative to CHX
- 2May be particularly useful for patients with staining concerns or sensitivity
- 3Needs more high-quality clinical data
Evidence Meter
Early studies and pilot data show promise, but larger trials are needed.
Frequently Asked Questions
References
Hypochlorous acid: A potential adjunctive therapy for periodontal disease
Kshirsagar AV et al. (2020)
DOI: 10.4103/2278-9626.201253Antimicrobial efficacy of hypochlorous acid in oral care
Pahwa N et al. (2020)
DOI: 10.1111/jcpe.13298Organisms Studied with This Therapy
Related Therapies
Educational use only. This page provides general information and does not recommend this therapy over others or provide medical advice. Always consult a licensed dental or medical professional for diagnosis and treatment decisions.