Fluoride release from CaF2 and enamel demineralization.

Area of Science:

• Dental research
• Cariology
• Fluoride chemistry

Background:

• The anticaries mechanism of professional fluoride (F) application is often linked to calcium-fluoride-like deposits (CaF(2)) on enamel.
• Direct evidence demonstrating this link and its effect on demineralization has been limited.

Purpose of the Study:

• To investigate if CaF(2) formed on enamel by F application reduces subsequent enamel demineralization.
• To determine if increased F availability in plaque fluid, due to CaF(2) deposits, mediates this effect.
• To evaluate a dose-response relationship between CaF(2) levels and anticaries outcomes.

Main Methods:

• Created varying levels of CaF(2) on enamel blocks.
• Exposed enamel blocks to *S. mutans* test plaque in situ with 10 volunteers.
• Measured F released into the "plaque fluid" before a cariogenic challenge.
• Assessed enamel demineralization post-challenge.

Main Results:

• A strong positive correlation was found between enamel CaF(2) concentration and F released into plaque fluid (r = 0.96, p < 0.001).
• A strong negative correlation was observed between plaque fluid F concentration and subsequent enamel demineralization (r = -0.75, p < 0.001).

Conclusions:

• Fluoride released from CaF(2) deposits into plaque fluid plays a crucial role in the anticaries efficacy of professional fluoride treatments.
• The formation of CaF(2) on enamel enhances F availability, thereby inhibiting enamel demineralization.