Erosion-Protective Benefit of Calcium Silicate Toothpaste on Natural Enamel Erosion

Objectives: To determine the erosive-protective properties of a calcium silicate, sodium phosphate and fluoride containing toothpaste on dental erosion in natural enamel in-vitro.
Methods: Natural human enamel specimens (n=30) were produced (5mm x 5mm x 3mm) and fixed to glass microscope slides using epoxy resin. Specimens (n=10/group) were randomly assigned to one of three pre-treatment groups: (1) calcium silicate and sodium phosphate salts toothpaste (1450ppm F as SMFP), (2) regular toothpaste (1450ppm F as SMFP), and (3) non-fluoride toothpaste. Pre-treatment consisted of toothpaste:water slurry (1:2) immersion (3 mins) followed by remineralisation (30 mins) in artificial saliva. Samples were taped and eroded (citric acid, 0.3% pH3.2) for 3x 5mins cycles (cumulative erosion times: 5, 10, and 15mins). Resulting lesions were measured/characterised quantitatively using changes in surface form (mean 3D step height change) and surface roughness (mean Sa), and qualitatively using tandem scanning confocal microscopy (TSM), and optical coherence tomography (OCT). Statistical analysis was conducted with two-way repeated measures ANOVA and post-hoc Tukey’s multiple comparisons.
Results: Treatment group (1) demonstrated lower mean(SD) 3D step height(μm) vs group (2) after 10 (1.08(0.27) vs 1.77(0.49), p<0.01) and 15 (1.96(0.40) vs 2.75(0.49), p<0.001) minutes, and group (3) at all erosion time points (p<0.01). Whilst for surface roughness, group (3) showed increased surface roughening compared with groups (1) and (2) after 10 and 15 minutes (p<0.001). Qualitative image analysis indicated group (1) after 5 and 10 minutes erosion demonstrated improved surface reflectivity properties and less evidence of surface destruction compared to groups (2) and (3).
Conclusions: Calcium silicate-based toothpaste provided longer lasting erosion-protective benefits with fewer erosive destructive features in natural enamel versus SMFP and non-F toothpaste groups.