Tooth Abrasivity and Tissue Loss using Surface Profilometry to Assess Oral Care Products

Assessment of oral care product tooth abrasivity through laboratory in vitro studies using surface profilometry to measure Relative Enamel Abrasivity (REA) and Relative Dentine Abrasivity (RDA) supporting oral care product development and marketing claims

Tooth abrasivity and tissue loss studies are important in determining the potential damage caused to enamel and dentine from oral care products such as toothpastes, tooth powders and even toothbrushes. Consumer and market trends towards specialised stain removal and tooth whitening products, has driven a growth in interest in this type of testing and the insight that can be gained from these studies supports product development (e.g. formulation development) or marketing claims.

Novel dentifrice formulations are constantly being developed to address the combined consumer need for improved tooth whitening combined with low abrasivity and minimal damage to enamel and dentine. Robust REA and RDA testing quantifies the potential for dentifrice products to abrade dental hard tissue.

Our in vitro clinical research scientists conduct abrasivity and tissue loss studies (REA and RDA) using surface profilometry providing key product development support or claims substantiation. Samples of human / bovine enamel or dentine are typically prepared in resin discs and polished to expose a flat and perfectly smooth surface. The edges of the specimen are masked off leaving the area of interest exposed. This area of the surface is then brushed using a mechanical brushing machine and a slurry of the test dentifrice under specific conditions of load, speed and duration.

Surface profilometry, either in two dimensions using a probe or in three dimensions using a laser scanner, is used to quantify the amount of tissue removed by the brushing process. At least six specimens are used for each test dentifrice and the mean depths are calculated. REA and RDA values are then calculated relative to a calcium pyrophosphate reference material as specified in ISO11609.

We present tooth abrasivity and tissue loss study data in professional laboratory reports which, depending on our knowledge of the formulation, may include a detailed interpretation of the results. We are also happy to engage with the client on how to improve their formulations or to suggest bespoke brushing experiments that seek a deeper understanding of abrasivity and tissue loss. We also have the capacity to investigate other surface properties using, for example, Scanning Electron Microscopy (SEM), Surface Microhardness (SMH), or a range of chromameters and gloss meters.

For over 20 years, our Clinical Research Services group has been a trusted partner for developers and manufacturers of oral care products offering Total Quality Assurance. We bring quality and safety to life by providing a one source solution for all of your oral care in vitro studies providing robust data to support the efficacy and safety of novel treatments. These in vitro studies can provide valuable information to support your product development process.