How does fluoride concentration in the tooth affect apatite crystal size?

Area of Science:

• Dental Research
• Materials Science
• Biomineralization

Background:

• Fluoride (F) is known for its caries prevention properties.
• The impact of varying fluoride concentrations on tooth apatite crystal structure remains largely uncharacterized.
• Understanding these effects is crucial for optimizing dental health strategies.

Purpose of the Study:

• To investigate the hypothesis that tooth fluoride concentration correlates with tooth crystallite size.
• To examine the relationship between environmental fluoride levels and the microstructural properties of enamel and dentin.

Main Methods:

• Analysis of 100 human unerupted third molars from regions with different water fluoride concentrations (Fortaleza, Brazil: 0.7 ppm; Toronto, Canada: 1.0 ppm; Montreal, Canada: 0.2 ppm).
• Fluoride concentration determined using Neutron Activation Analysis.
• Apatite crystallite size (length and width) measured by powder X-ray diffraction.

Main Results:

• A significant positive correlation was observed between dentin fluoride concentration and enamel crystallite length and width.
• Teeth from Fortaleza, with higher water fluoride, exhibited significantly greater enamel crystallite length and width compared to those from Toronto and Montreal.
• No significant differences in dentin crystallite size were found across the three regions.

Conclusions:

• Tooth fluoride concentration is directly correlated with enamel apatite crystallite size.
• Higher environmental fluoride exposure leads to larger enamel crystallite dimensions.
• These findings provide new insights into the structural effects of fluoride on dental tissues.