FLUORIDE PENETRATION DEPTH AND ITS IMPACT ON WHITE SPOT LESIONS AND MOLAR INCISOR HYPO-MINERALIZATION: A LITERATURE REVIEW

Background: Fluoride (F) is an effective anticaries agent and can be delivered through various mediums at
different concentrations. A pivotal aspect of fluoride’s effectiveness is its ability to penetrate enamel, impacting its
remineralizing potential but limited comparative data exists on their effects on lesion depth.
Objective: To evaluate the efficacy of topical fluoride on lesion depth specifically by comparing its effects on
white spot lesions and Molar Incisor Hypo-mineralization (MIH).
Material and Methods: Literature review included 16 references dated from 2021 to 2024. The articles were
divided into 6 clinical studies analyzing the Fluoride effect on enamel lesions and 4 articles treating its effect on
MIH lesions. In addition, 4 studies revealing depth of enamel lesions and a reviewing of EAPD and ICDAS
international guidelines.
Results: In healthy enamel and early carious lesions such as white spot lesions (WSLs), fluoride primarily acts on
the superficial layers, typically within the outer 30-50 μm, promoting remineralization and inhibiting
demineralization. However, deeper penetration is often limited, making fluoride less effective in reversing more
advanced subsurface demineralization. In contrast, molar incisor hypo-mineralization (MIH) affected enamel is
structurally compromised, with porosities extending much deeper (often beyond 300 𝜇m), making it less receptive to
conventional fluoride treatments.
Conclusion: Although Fluoride is frequently recommended, its remineralization effect on MIH lesions is limited,
whereas it has been proven effective on white spot lesions.