Which of the following is the primary mechanism of action of fluoride on topical application?
The presence of fluoride reduces the solubility of enamel by promoting the precipitation of hydroxyapatite and phosphate mineral. Ca10(P04)6(OH)2 +2F- -> Ca10(PO4)6F2 + 2OH (OH ions are replaced) (hydroxy-apatite) (fluro-apatite) Ref: Essentials of Pedodontics By Tilakraj, Pages 182-3 ; A Textbook of Public Health Dentistry By Marya, Page 348
Forming a reservoir in saliva
Inhibition of plaque bacteria
Improvement in tooth morphology
Conversion of hydroxyapatite to fluorapatite by replacing the OH- ions