Comparison of the Antimicrobial Effect of Hydrogen Water and Chlorhexidine Mouth rinse in Toothbrush Disinfection Among Dental Students.
Vaishnavi C, Elangovan GP, Thirumal M, Prashanth SV, Deepika D, Pragathi TG. · Journal of Pharmacy and Bioallied Sciences. 2025;17:1565-24.
What kind of evidence is this?
Human
Parallel comparative study
Oral and dental health
Other forms
Positive laboratory signal with serious methodological limitations.
Laboratory microbial outcome; not a patient health outcome.
Methods at a glance
Dental students whose used toothbrushes were assigned to disinfection procedures.
30 students; 15 toothbrushes per intervention group.
Seven days.
Toothbrush immersion in freshly prepared hydrogen water for seven days of the study protocol.
H2 dissolved in water; not Brown's gas.
The hydrogen concentration was not reported.
Not applicable — toothbrush immersion.
No oxygen was co-delivered.
Chlorhexidine mouth-rinse solution.
Outcomes and reported result
Microbial colony-forming units recovered from toothbrushes.
The article reports lower recovered colony counts in the hydrogen-water group than in the chlorhexidine group.
The full article, methods and reported colony-count comparisons were checked.
A reported association, difference or mechanism is not automatically a clinical benefit. Null findings, outcome type, study design and precision all matter.
Cautions and applicability
Small study, unclear allocation and blinding, unreported hydrogen concentration and a toothbrush laboratory endpoint; it does not show a clinical oral-health benefit.
Toothbrush disinfection under the reported protocol.
ROBINS-I — preliminary
Serious concerns
Allocation procedures and blinding were unclear, and the endpoint was a laboratory surrogate.
Non-random selection or allocation · Confounding and co-intervention concerns · Attrition/reporting checked where stated · Some outcomes are subjective or laboratory-only · No outcome-level protocol comparison completed
No single-study GRADE certainty rating is assigned. Certainty is assessed by important outcome across a complete eligible evidence set, not by attaching a final grade to one source.
Sources and record status
PMID: 40511014 · DOI: 10.4103/jpbs.jpbs_1565_24
Free full article in PubMed Central.
PubMed record and PubMed Central full text; extraction checked 9 August 2026.
2026-08-10