The effect of different fluoride application methods on the remineralization of initial carious lesions

Abstract

Objectives: The purpose of this study was to assess the effect of single and combined applications of fluoride on the amount of fluoride release, and the remineralization and physical properties of enamel.

Materials and methods: Each of four fluoride varnish and gel products (Fluor Protector, FP, Ivoclar Vivadent; Tooth Mousse Plus, TM, GC; 60 Second Gel, A, Germiphene; CavityShield, CS, 3M ESPE) and two fluoride solutions (2% sodium fluoride, N; 8% tin(ii) fluoride, S) were applied on bovine teeth using single and combined methods (10 per group), and then the amount of fluoride release was measured for 4 wk. The electron probe microanalysis and the Vickers microhardness measurements were conducted to assess the effect of fluoride application on the surface properties of bovine teeth.

Results: The amount of fluoride release was higher in combined applications than in single application (p < 0.05). Microhardness values were higher after combined applications of N with FP, TM, and CS than single application of them, and these values were also higher after combined applications of S than single application of A (p < 0.05). Ca and P values were higher in combined applications of N with TM and CS than single application of them (p < 0.05). They were also increased after combined applications of the S with A than after single application (p < 0.05).

Conclusions: Combined applications of fluoride could be used as a basis to design more effective methods of fluoride application to provide enhanced remineralization.

Keywords: Dental Caries; Electron probe microanalysis; Fluorides; Remineralization; Vickers hardness.

Figure 1. Mean Vickers microhardness of specimen surface after fluoride applications (n = 4). Bars indicate standard deviations. Non, Untreated; FP, Fluor Protector; FPN, Fluor Protector + 2% sodium fluoride (NaF); FPS, Fluor Protector + 8% tin(ii) fluoride (SnF₂); TM, Tooth Mousse Plus; TMN, Tooth Mousse Plus + 2% NaF; TMS, Tooth Mousse Plus + 8% SnF₂; A, 60 Second Gel; AN, 60 Second Gel + 2% NaF; AS, 60 Second Gel + 8% SnF₂; CS, CavityShield; CSN, CavityShield + 2% NaF; CSS, CavityShield + 8% SnF₂.

a - d, Groups with different letters were significantly different (p < 0.05). HV_0.2, Hardness values were determined using a digital microhardness tester with a load of 0.2 kg.

Figure 2. Fluoride release after fluoride applications (n = 5). Bars indicate standard deviations. Non, Untreated; FP, Fluor Protector; FPN, Fluor Protector + 2% sodium fluoride (NaF); FPS, Fluor Protector + 8% tin(ii) fluoride (SnF₂); TM, Tooth Mousse Plus; TMN, Tooth Mousse Plus + 2% NaF; TMS, Tooth Mousse Plus + 8% SnF₂; A, 60 Second Gel; AN, 60 Second Gel + 2% NaF; AS, 60 Second Gel + 8% SnF₂; CS, CavityShield; CSN, CavityShield + 2% NaF; CSS, CavityShield + 8% SnF₂.

Figure 3. Calcium content of specimens after fluoride applications by EPMA analysis. Bars indicate standard deviations. Non, Untreated; FP, Fluor Protector; FPN, Fluor Protector + 2% sodium fluoride (NaF); FPS, Fluor Protector + 8% tin(ii) fluoride (SnF₂); TM, Tooth Mousse Plus; TMN, Tooth Mousse Plus + 2% NaF; TMS, Tooth Mousse Plus + 8% SnF₂; A, 60 Second Gel; AN, 60 Second Gel + 2% NaF; AS, 60 Second Gel + 8% SnF₂; CS, CavityShield; CSN, CavityShield + 2% NaF; CSS, CavityShield + 8% SnF₂.

a - d, Groups with different letters were significantly different (p < 0.05).

Figure 4. Phosphorus content of specimens after fluoride applications by EPMA analysis. Bars indicate standard deviations. Non, Untreated; FP, Fluor Protector; FPN, Fluor Protector + 2% sodium fluoride (NaF); FPS, Fluor Protector + 8% tin(ii) fluoride (SnF₂); TM, Tooth Mousse Plus; TMN, Tooth Mousse Plus + 2% NaF; TMS, Tooth Mousse Plus + 8% SnF₂; A, 60 Second Gel; AN, 60 Second Gel + 2% NaF; AS, 60 Second Gel + 8% SnF₂; CS, CavityShield; CSN, CavityShield + 2% NaF; CSS, CavityShield + 8% SnF₂.

a - c, Groups with different letters were significantly different (p < 0.05).