In vitro evaluation of the effects of different particle types in toothpastes on the efficacy against enamel erosion and wear

Abstract

The effects of the particle fraction in toothpastes in the context of erosion and erosive tooth wear has not been fully elucidated. Thus, aim of this study was to investigate experimental toothpastes, each with one specific particle type. Toothpastes with seven different types of silica or alumina were prepared as slurry either with or without active ingredients (NaF or F/Sn). Human enamel samples were exposed to a cyclic erosion/abrasion model, and were either treated with the respective slurries only or additionally brushed in a brushing machine. Tissue loss was profilometrically monitored. After treatment with slurries without active ingredients or with NaF, tissue loss increased significantly within groups over time (p < 0.001 each). At the end of the trial, there were minor differences between groups (not exceeding 10–20%; p > 0.05 for most comparisons). After treatment with the F/Sn slurries, tissue loss stagnated completely over time, with the exception of one silica type and alumina, but both still reduced tissue loss by 40–50% (compared to control p < 0.001 each). Relative to the type of the active ingredient, the particle type seems to be a secondary factor for the efficacy of toothpastes on erosion and erosive tooth wear in enamel.

In vitro study on the preventive effect of children’s toothpastes on erosive tooth wear of primary bovine enamel and dentin

“…However, as relative rather than absolute values are of interest, it seems reasonable to use an in vitro design with artificial saliva to roughly assess the erosion-protective capacity of oral care products. Moreover, as commercially available toothpastes were analysed, we could not control for specific toothpaste characteristics, such as wettability, pH, size and mount of abrasive particles 37 , 38 .…”

“…Nevertheless, it has to be emphasized that even toothpastes with low fluoride concentration were effective in reducing erosive dentin loss, which might be of particular relevance for children suffering from severe erosive tooth wear already affecting dentin. Differences between toothpastes with the same fluoride concentration, but of different brands might be related to the abrasivity (RDA-value), particle type and further physical and chemical factors of the toothpaste, which can—at least partly—affect the protective properties of active ingredients 37 , 38 , 52 .…”

“…Interestingly, toothbrushing did not lead to a significant increase of surface loss compared to the erosion only groups (except for Splat Baby, Splat Kids and Splat Junior in enamel), although previous studies demonstrated that eroded primary and permanent enamel 22,[39][40][41] and dentin 23,42 as well as enamel presenting initial caries 43 are susceptible to brushing leading to an increased surface loss. However, under less exaggerated conditions with short brushing treatment simulating clinical conditions it was shown that the abrasive effect is less pronounced www.nature.com/scientificreports/ and even counteracted by the effects of fluorides 37,38,[44][45][46] . In the present study, each toothbrushing was performed for 15 s (equal to 20 brushing strokes) leading to an incomplete removal of the erosively softened surface layer resulting to less than 100 nm enamel loss loss 47 .…”

Effect of different brushing parameters on erosive tooth wear in primary bovine enamel and dentin

“…Confirming the results of previous studies [ 4 , 8 ], brushing with the fluoridated toothpaste was able to reduce erosive tooth wear in primary enamel and especially in primary dentin, while tooth loss was not different from the controls (erosion only) after brushing with the fluoride-free toothpaste. More recent studies on permanent dental hard tissue have already shown that the preventive effect by the application of fluoridated toothpastes exceeds potential adverse effects (abrasion) from toothbrushing as long as exaggerated brushing is avoided and short brushing treatment simulating clinical conditions is performed [ 9 , 30 ].…”

“…A recent study has shown that brushing with fluoride containing children's toothpastes was able to prevent erosive tooth wear in primary dental hard tissue, especially in dentin, where even toothpastes with a lower fluoride concentration (500 ppm) were effective in reducing erosive wear [8]. However, from studies performed in permanent teeth it is known that brushing as such might reduce the protective effect of fluoride toothpastes compared to the toothpaste application as slurry, as particle type and size, wettability or calcium and phosphate concentration of the toothpastes partly counteract the effects of fluorides [9][10][11]. Moreover, the toothbrush itself, filament stiffness and the applied brushing force might also modify the abrasion of eroded dental hard tissue [12][13][14][15].…”