The Effect of Fluoridated Dentifrice Formulations on Enamel Remineralisation and Microhardness after in Vitro Demineralization

Purpose: The aim of this study is to assess the effect of commercially available dentifrices with different fluoride formula on remineralisation of enamel surface. Material and Methods: Enamel blocks were ground flat with water-cooled carborundum discs (320, 600 and 1200 grit) and randomly divided into seven groups. The specimens were subjected to a daily cycling regime comprising two one-minute brushing treatments ; one before and one after the demineralization period of 6 hours and 18 hours, and remineralisation in artificial saliva. During the pH cycling regimen each of those seven groups were treated with different dentifrices: fluoride dentifrice Sensodyne Rapid (1040 ppm NaF), Colgate Total (1100 ppm NaF), Parodontax fluoride (1400 ppm NaF), Sensodyne fluoride (1400 ppm NaF), Pronamel Sensodyne (1450 ppm NaF), Elmex-GABA International (1250 ppm F Amine fluoride), and fluoride free Detartrine Paste (Septodont). The surface microhardness (SMH) of those specimens was determined at baseline and after 12 days using HMV-2000 (50 g, 490.3 mN, 10 s) (Shimadzu, Japan). Results: All specimen groups treated with fluorides showed increase in SMH compared to control group. Pronamel, Sensodyne F, Sensodyne Rapid and Colgate Total were statistically superior to other fluoride dentifrices and a fluoride-free control after 12 days pH-cycling regime. Rates of enamel microhardness at baseline and after 12 days cycling treated with Parodontax obtained increase in SMH, but it was not statistically significant (p>0.05). Conclusion: The results obtained in the present study show that high fluoride toothpastes (1450 ppm) effectively inhibit demineralization under experimental conditions.