Effect of a Sodium Fluoride-Releasing Rubber Cup on Hydroxyapatite Crystallinity of Human Enamel: FTIR Spectroscopy Analysis
Author(s): Giulia Orilisi, Riccardo Monterubbianesi, Vincenzo Tosco, Carla Conti, Maurizio Procaccini, Angelo Putignano, Giovanna Orsini
Fluoride application is an important strategy to reduce demineralization and enhance remineralization in human teeth. This study aimed to evaluate the effect on enamel hydroxyapatite (HA) crystallinity (C) of a sodium fluoride-releasing rubber cup compared to a non-fluoride rubber cup, using Fourier Transformed Mid Infrared Spectroscopy (FTMIR) analysis. First class direct composite restorations were performed in ten sound extracted molars. Teeth were then divided into two groups (n=5): Control group, polished with non-fluoride rubber cup (noFHA), for 10 s; Tested group, polished with a sodium fluoride-releasing rubber cup (FHA), for 10 s. Samples were scraped off on the treated surfaces with abrasive paper and the dust was analyzed using FTMIR. Spectra were acquired in the range of 4000-400 cm-1 and each spectrum represented the average of 5 measurements. Phosphate (PO4) vibration at 604 cm-1 was used to analyze C: the full width at half maximum (FWHM) of noFHA was lower than the one of FHA; thus, sodium fluoride, contained in the rubber cup, increased C. The absorption at 1090 cm-1 can be considered an additional marker of C, indeed the peak of FHA was higher than the one of HA and noFHA, thus suggesting increasing and stabilizing of the enamel C. In conclusion, the tested sodium fluoride-releasing rubber cup could be an effective polishing system since it not only allows to polish the tooth surface, but also improves the C of enamel HA, thanks to the quick bond done by fluoride.