Effect of pH of amine fluoride containing toothpastes on enamel remineralization in vitro.
Level 5 - mechanism / opinion, no new human data
In vitro bench research using extracted human teeth.
PubMed 17941981 · doi:10.1186/1472-6831-7-14
What was done
Forty caries-free extracted human premolars with a 5 x 5 mm enamel window were artificially demineralized in a hydroxyethylcellulose solution at pH 4.8. The teeth were allocated across 8 groups (n = 5 per group). Each specimen had a varnish-covered half acting as control and an exposed half immersed in an amine fluoride (1400 ppm) toothpaste slurry at pH 4.1, 4.5, 5.1, or 6.9, or a non-fluoridated control slurry at pH 4.3, 4.7, 5.3, or 7.0. Lesions were evaluated using polarizing light microscopy (PLM) to determine pore volume and energy-dispersive X-ray spectroscopy (EDX) for quantitative element analysis.
What was found
PLM analysis showed a decreased pore volume in the lesion body after incubation with fluoridated toothpaste at pH 4.53 and 5.16. No differences between the experimental and control windows were observed in the other fluoride groups (pH 4.1, 6.9) or in any of the non-fluoridated groups. Quantitative EDX elemental analysis showed no significant differences in elemental content across any group. No numerical values or p-values were reported in the abstract.
Why it matters
These findings suggest that slightly acidic formulations (pH ~4.5 to 5.2) may modestly enhance the remineralizing efficacy of amine fluoride dentifrices compared to neutral or more acidic preparations.
Limits
This was an artificial in vitro study on extracted teeth, which cannot replicate intraoral biological factors such as saliva flow, pellicle formation, or oral biofilm. The sample size was small (5 teeth per condition), and microscopic evidence of remineralization was not corroborated by elemental analysis. No exact numerical data or variance estimates were provided in the abstract.
Cited by
- supports Acidifying the mouth enhances the remineralization capacity of fluoride.