The effect of fluoride on the developing mineralized tissues

Area of Science:

• Biomineralization
• Dental Research
• Skeletal Biology

Background:

• Fluoride is a common environmental ion with known effects on calcified tissues.
• Understanding non-cytotoxic fluoride concentrations is crucial for assessing its biological impact.
• Previous research has focused on high fluoride levels, necessitating investigation into lower, physiologically relevant concentrations.

Purpose of the Study:

• To investigate the effects of non-cytotoxic fluoride concentrations (up to 1-2 µmol/L) on tooth and bone development.
• To explore the mechanisms by which fluoride influences cellular and matrix processes during biomineralization.
• To determine the reversibility and potential implications for enamel and bone maturation.

Main Methods:

• Analysis of plasma and cellular fluoride concentrations.
• Examination of gene expression related to odontogenesis and bone development.
• Assessment of extracellular matrix protein processing and mineral phase interactions.
• Utilizing explant studies to evaluate reversibility of fluoride effects.

Main Results:

• Gene expression modulation in odontogenesis was minimal.
• Evidence suggests fluoride may possess osteogenic properties in both embryonic and adult tissues.
• Subtle alterations in enamel matrix composition and impaired matrix removal/maturation were observed.
• Explant studies indicated that fluoride's effects on calcified tissues may be reversible.

Conclusions:

• Non-cytotoxic fluoride concentrations can subtly alter calcified tissue development, particularly affecting matrix processing and maturation.
• Fluoride's primary site of action appears to be the matrix or mineral-matrix interactions, rather than direct gene expression modulation.
• Inhibition of proteolysis during enamel maturation is a likely mechanism for impaired crystal growth, suggesting caution in interpreting animal models of enamel dysplasia.