pH and Erosive Potential of Commonly Used Oral Moisturizers.
Level 5 - mechanism / opinion, no new human data
In vitro bench research on human dentin specimens without clinical trial data.
PubMed 26216576 · doi:10.1111/jopr.12324
What was done
The pH of seven commercial oral moisturizers was measured in triplicate across three bottles per product. Human dentin blocks were submerged in 5 ml of each moisturizer, tap water (control), or citric acid (control) for 15 days, with gravimetric measurements recorded at baseline, 24 hours, 48 hours, 96 hours, 1 week, and 15 days to quantify dentin structure loss.
What was found
Average pH values were: citric acid 1.33, Mouth Kote 3.0, Biotène Moisturizing Mouth Spray 6.1, Oasis 6.3, Thayer's 6.3, Biotène Oral Balance 6.6, tap water 6.99, Rain 7.1, and CTx2 Spray 9.1. After 2 weeks, dentin loss was: citric acid 18.8%, Mouth Kote 9.6%, Biotène Moisturizing Mouth Spray 4.6%, Oasis 3.2%, Thayer's 2.0%, and 0.0% for Biotène Oral Balance, Rain, CTx2 Spray, and tap water. There was a significant negative correlation between pH and erosive potential (rs = -0.73; P ≤ 0.0001).
Why it matters
Patients with dry mouth rely on oral moisturizers for symptomatic relief but are already susceptible to erosion. Choosing acidic formulations could inadvertently accelerate demineralization and dental tissue loss.
Limits
The study was entirely in vitro using continuous 15-day submersion, which does not reflect dynamic oral conditions such as intermittent exposure, saliva clearance, or salivary pellicle buffering. The abstract does not state the total number of dentin blocks tested.
Cited by
- contradicts Biotene dry mouth rinse had a pH of approximately 4.5 for years.