A comparison of protection given from toothpastes to erosion

Methods: Polished human enamel specimens (n=4/gp) were immersed in 20ml of human saliva for 60mins to formulate initial pellicle formation. Each group was subjected to erosion-cycling regimen consisting of 4 cycles/day over 5 days. Each cycle consisted of immersion in a toothpaste slurry for 2mins (1:3 toothpaste/fresh pooled human saliva), 60mins remineralisation in human saliva and 10mins in 1% citric acid at natural pH. Four enamel specimens were tested each with Crest Cavity (1100ppm F as NaF), Aquafresh White & Complete Care (1450ppm F as NaF) Sensodyne Pronamel (1450ppm F as NaF), Signal Integral 8 (1450 ppm F as NaF), Colgate Total (1450ppm F as NaF), GC Toothmouse (0ppm F), Rembrandt Complete (1450ppm F as NaF), Meridol (1400ppm F as 350ppm AmF+1050ppm SnF₂), Crest ProHealth (1100ppm as SnF₂) and Oral B ProExpert (1450ppm F as 350ppm NaF+1100ppm SnF₂). Specimens were analysed using transverse microradiography (TMR) and profilometry and mean surface loss calculated using previously validated methods.

Results: The mean step height for all pastes was 17.9um with the lowest being Oral B ProExpert but there were no statistically significant differences between the products. Data from microradiography using Fisher’s Least Significant Difference (LSD) test showed that the least protective toothpastes were: Crest Cavity, Aquafresh, Sensodyne Pronamel, Signal 8 and Colgate Total. There were no significant differences within this group. A signficantly increased protective effect (p < 0.05) compared to all other pastes was found for Crest ProHealth and Oral B ProExpert. 

Conclusions: Within the limitations of this study toothpastes with stabilised stannous technology appeared to offer significantly better protection of human enamel. Although not significantly different, the data from the profilometry showed a similar trend to the TMR.