Protective benefits of a stabilised stannous-containing fluoride dentifrice against erosive acid damage

Abstract

Purpose: To assess the potential of a stabilised stannous (Sn)-containing NaF dentifrice (Oral B/blend-a-Med(®) Pro-Expert), in addition to a number of other marketed European dentifrices formulated with various fluoride actives and two control dentifrices, to protect enamel against erosive acid damage.

Methods: Cores of human enamel (four per group) were soaked in pooled human saliva, and then treated with a 1:3 slurry (dentifrice:saliva) using a standardised in vitro erosion model (5-day cycling) that includes 10-minute challenges with 1% citric acid applied 60 minutes after each dentifrice treatment. Enamel surface loss was measured using transverse microradiography (TMR).

Results: Specimens treated with the Sn-containing NaF dentifrice showed 6.5 μm of surface loss ± 1.2 (SEM), which was not significantly different (P < 0.05, Fisher LSD) from that of a clinically proven, stabilised SnF2 positive control [Crest(®) Pro-Health, 1,100 ppm F as SnF2 : 3.0 μm of surface loss ± 1.1 (SEM)]. The Sn-containing NaF dentifrice and the clinically proven positive control both provided significantly greater protection (P < 0.05, Fisher LSD) compared with all of the other products tested. Enamel loss (SEM) values for other European products and the reference control (active agents) were: Meridol(®) : (1,400 ppm F as AmF + SnF2 ) 12.0 μm (1.47); Colgate(®) Cavity Protection: (1,450 ppm F as SMFP + NaF) 12.9 μm (1.66); Odol med 3(®) (1,400 ppm F as NaF) 14.2 μm (1.49); Elmex(®) (1,400 ppm F as AmF) 14.5 μm (1.76); Colgate(®) Enamel Protect: (1,450 ppm F as NaF + KNO3 ) 16.3 μm (2.02); Lacalut(®) aktiv: (1,400 ppm F as AlF3 ) 18.5 μm (1.71); Sensodyne(®) ProNamel(™) : (1,450 ppm F as NaF + KNO3 ) 20.5 μm (1.26); Crest Cavity Protection (1,100 ppm F as NaF, reference control) 22.00 μm (2.04); and Mentadent(®) : (1,450 ppm F as NaF + Zn citrate) 22.3 μm (0.63).

Conclusion: These results support the potential for the stabilised, Sn-containing NaF dentifrice to provide erosion protection benefits that are not significantly different from the positive control benchmark for erosion protection (stabilised SnF2 ), and are significantly better than a broad range of dentifrice formulations available on the European market.

Keywords: Erosion; Sn-containing; dentifrice; fluoride; stannous.

Figure 1.

Visual description of the model. (a) example of a 3 mm core of human enamel removed from an extracted, human tooth; (b) 3 mm cores of enamel after mounting in ¼ inch (0.64 cm) diameter Lucite rods, then ground and polished in preparation for the study (left) and after placement of nail polish on the tooth surface, leaving a treatment window approximately 0.4 mm wide; (c) each group of four specimens was mounted in a holding appliance that enabled treatment of all specimens in the group at the same time; (d) the holding appliance with four rod-mounted specimens is attached to the bit of a controlled-speed motor and suspended for treatment; (e) after treatment, each group of specimens is suspended in pooled, human saliva using gentle agitation (stirring bars) over a multi-place stir-plate.

Table 2

Results and statistical analysis