Tap water filtration and purification usage and their impact on the concentrations of fluoride and other minerals - A community-based study.
Level 4 - case-series / case-control
Cross-sectional survey and water sampling study
PubMed 39349095 · doi:10.1016/j.jdent.2024.105377
What was done
Researchers surveyed 101 residents in central Indiana (USA) regarding demographics, water sources, and use of water filtration and purification systems (WFPS). Participants provided water samples from their tap or WFPS. Water samples were tested for fluoride using ion-specific electrodes, and for calcium, magnesium, potassium, and sodium using atomic absorption spectrometry. Mineral concentrations and questionnaire data were analyzed using non-parametric tests, chi-square tests, and correlations.
What was found
Among the 101 participants, 71% reported using a WFPS. Usage was higher among individuals with a bachelor's degree or higher (p = 0.003) and lower among Black participants compared to Asian or White participants (p = 0.045). Pitcher filters were the most commonly used system (31%), followed by water softeners (21%), reverse osmosis (11%), faucet-mounted filters (4%), and whole-house carbon filters (1%). Reverse osmosis systems produced the lowest median mineral concentrations (fluoride: 0.08 ppm, calcium: 2.30 ppm, magnesium: 0.46 ppm, sodium: 4.60 ppm, potassium: 0.35 ppm). Pitcher filters yielded mineral concentrations comparable to unfiltered tap water, while water softeners produced the highest sodium levels (median 78.40 ppm).
Why it matters
Patients using reverse osmosis systems may deplete protective fluoride and essential minerals from their drinking water, informing dental caries risk assessments and the need for supplemental fluoride.
Limits
The study had a small sample size (n = 101) restricted to a single geographic area (central Indiana), limiting generalizability. Specific device brands, filter ages, and maintenance schedules were not detailed in the abstract, and baseline source water mineral levels before filtration were not paired across all individual samples.
Cited by
- supports Reverse osmosis water filtration removes essential minerals and trace elements such as phosphorus, manganese, and iodine from drinking water.