Protective effects of SnF2 – Part II. Deposition and retention on pellicle-coated enamel

Deposition of an acid-resistant barrier onto enamel represents a potentially superior means for delivering protection against dietary, erosive acid challenges.PurposeThe purpose of this study was to demonstrate the ability of a stabilised stannous fluoride (SnF2) dentifrice to: (1) deposit a SnF2 barrier layer onto pellicle-coated enamel surfaces; (2) increase the intensity of the barrier layer over time; and (3) be retained on the enamel surface for hours after product use.MethodsSquares of human enamel were exposed to pooled saliva for 1hour (pellicle formation) and separated into six sets. Set 1 was treated with the supernatant of a 1:3 slurry of the test dentifrice (Crest((R)) Pro-Health((R)): water for 2minutes), then rinsed. Set 2 was treated in the same manner and then placed into saliva (6hours). Set 3 was cycled through seven repeated treatments. Set 4 was treated for seven cycles and then placed into saliva (6hours). Set 5 was a water control, and set 6 was a water control that remained in saliva for 6hours. Surface analysis of specimens was done using laser ablation Inductively Coupled Plasma Mass Spectroscopy (ICP-MS).ResultsDeposition of a barrier layer was demonstrated, beginning with the initial treatment, with Sn (using isotopes Sn-117+Sn-120) measured on the enamel surface as the reference marker. Deposition of the barrier layer was greater after seven cycles, and the retention of this layer was highly significant (P=0.05, anova: 6hours).ConclusionsThis study confirms that: (1) the stabilised SnF2 dentifrice deposits a barrier layer onto the enamel surface, beginning with the first use of the product; (2) this barrier is enhanced following multiple treatments; and (3) the barrier layer is retained on the enamel surface for hours after product use.