AUTHOR=Nino Svanishvili , Marina Mamaladze , Labanca Mauro , Dea Vadachkoria 
  
TITLE=Elemental changes in tooth hard tissues during demineralization and fluoride-induced remineralization: an SEM-EDX study
  
JOURNAL=Acta Biochimica Polonica
  
VOLUME=Volume 73 - 2026
  
YEAR=2026
  
URL=https://www.frontierspartnerships.org/journals/acta-biochimica-polonica/articles/10.3389/abp.2026.16706
  
DOI=10.3389/abp.2026.16706
  
ISSN=1734-154X
  
ABSTRACT=BackgroundTooth enamel and dentin are the most highly mineralized tissues in the human body, and their structural stability depends on the balanced content of calcium (Ca), phosphorus (P), and fluoride (F). Demineralization leads to the loss of these ions, weakening the tooth structure and increasing susceptibility to caries.ObjectiveThis study aimed to evaluate elemental changes in Ca, P, and F in intact, demineralized, and remineralized teeth across the enamel, dentin–enamel junction and peripulpal dentin.Materials and methods45 extracted human teeth were longitudinally sectioned to yield 90 paired specimens. One half of each tooth served as a baseline (intact) control, while the corresponding half was subjected to acid-induced demineralization. Following demineralization, the experimental halves were randomly assigned to one of three remineralization protocols (n = 15 per group): fluoride varnish, fluoride toothpaste with rinsing, and fluoride toothpaste without rinsing. Elemental composition was analyzed using scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDX). Statistical analysis included paired t-tests for within-tooth comparisons and one-way ANOVA for treatment effects (p < 0.05).ResultsAt baseline, enamel exhibited significantly higher calcium and phosphorus levels compared to dentin regions. Demineralization resulted in a significant reduction in mineral content, particularly in dentin, along with complete loss of detectable fluoride (p < 0.0001). Remineralization increased calcium and fluoride levels across all groups. Fluoride varnish showed the highest fluoride retention trend, particularly in enamel; however, no statistically significant differences were observed among treatment groups for calcium and phosphorus.ConclusionFluoride-based treatments contributed to partial remineralization of tooth hard tissues. Fluoride varnish showed a tendency toward greater fluoride incorporation, particularly in enamel; however, statistically significant superiority over other treatment approaches was not demonstrated. These findings support the role of fluoride in remineralization while highlighting the need for further clinically relevant studies.