Toothpaste Abrasion and Abrasive Particle Content: Correlating High-Resolution Profilometric Analysis with Relative Dentin Abrasivity (RDA)

Abstract

In this in vitro study, the influence of the concentration of abrasive particles on the abrasivity of toothpastes was investigated using laser scan profilometry on polymethyl methacrylate (PMMA) surfaces with the aim of providing an alternative method to developers for screening of new toothpaste formulations. PMMA plates were tested in a toothbrush simulator with distilled water and four model toothpastes with increasing content of hydrated silica (2.5, 5.0, 7.5, 10.0 wt%). The viscosity of the model toothpaste formulations was kept constant by means of varying the content of sodium carboxymethyl cellulose and water. The brushed surfaces were evaluated using laser scan profilometry at micrometer-scale resolutions, and the total volume of the introduced scratches was calculated along with the roughness parameters Ra, Rz and Rv. RDA measurements commissioned for the same toothpaste formulations were used to analyze the correlation between results obtained with the different methods. The same experimental procedure was applied to five commercially available toothpastes, and the results were evaluated against our model system. In addition, we characterize abrasive hydrated silica and discuss their effects on PMMA-sample surfaces. The results show that the abrasiveness of a model toothpaste increases with the weight percentage of hydrated silica. Increasing roughness parameter and volume loss values show good correlation with the likewise increasing corresponding RDA values for all model toothpastes, as well as commercial toothpastes without ingredients that can damage the used substrate PMMA. From our results, we deduce an abrasion classification that corresponds to the RDA classification established for marketed toothpastes.

Caries Etiology and Preventive Measures

“…50,63 In contrast 24 to the toothbrush filaments (millimeter scale), state-of-theart toothpaste abrasives such as hydrated silica have a specific microscopic structure (nanometer to micrometer scale) that can help clean even pits and fissures. 64 Calciumcontaining toothpaste abrasives (e.g., dicalcium phosphate dihydrate, calcium carbonate, calcium pyrophosphate, and hydroxyapatite) can also support the tooth remineralization process. Abrasives that are soft or have a medium hardness are often preferred since they are not harmful to exposed dentin and gingiva.…”

“…In general, the abrasion (and consequently the cleaning efficacy) is increased with increasing concentration of abrasives. 64 Notably, the amount of toothpaste used for tooth brushing has a significant impact on the cleaning efficacy. 65 Fluoridated toothpastes for children have to be used in small amounts only, due to regulatory and toxicological reasons.…”

“…In general, the abrasion (and consequently the cleaning efficacy) is increased with increasing concentration of abrasives. 64 …”

Effect of Whitening Toothpastes with Different Active Agents on the Abrasive Wear of Dentin Following Tooth Brushing Simulation

“…Quantitative evaluation of abrasive dentin wear after brushing with whitening toothpastes can be implemented by measuring the amount of dentinal tissue that was removed. The standard approach involves assessing the relative dentin abrasivity (RDA) of the toothpaste, which can be measured using either the radiotracer (Rt) method or the profilometry equivalent method (RDA-PE) [16] in accordance with the guidelines set out in ISO 11609:2017(E) [17]. Nevertheless, the complexity of the method and the time-consuming and cost-intensive procedure, as well as its sensitivity to various factors such as dentinal substrate and reference abrasives, have led to modifications of this testing.…”

Effect of Different Whitening Toothpastes on Surface Roughness of Young Human Enamel

“…In accordance with the present study, Schwarzbold et al (2021) and de Moraes Rego Roselino et al, (2015) have demonstrated that simulating 3,600 brushing cycles over three months, with a focus on minimizing the toothbrush effect by using a soft bristle toothbrush, respectively. www.ijmsdh.org 92Similarly other studies, the mixture used during brushing was prepared by homogenizing 25 grams of toothpaste with 40 ml of distilled water for each group in our study(Enax et al, 2023;Vieira Vilhena et al, 2022). The combination represents the test mixture specified by ISO standards (ISO 11609-2017).…”