Dental abrasion is the gradual wear on tooth structure, affecting the hard outer enamel and the softer dentin layer beneath it. This physical loss of material can lead to increased tooth sensitivity, gum recession, and changes in appearance. While several factors contribute to this condition, the cleaning agents within toothpaste are a common source of mechanical wear. Selecting a toothpaste with low abrasive properties is an important step in protecting long-term oral health.
Understanding Relative Dentin Abrasion (RDA) Scores
The abrasiveness of toothpaste is quantified using the standardized Relative Dentin Abrasion (RDA) score. RDA is a laboratory value determined by the amount of dentin removed during a controlled brushing simulation. This measurement compares the abraded material to a reference abrasive set at a value of 100.
This scale provides a reliable way to compare the physical harshness of different toothpaste formulas. The RDA scale typically ranges from 0 to over 250, where higher numbers indicate greater abrasiveness. The American Dental Association (ADA) considers any toothpaste with an RDA score of 250 or less to be safe for daily use.
Toothpastes with an RDA between 0 and 70 are classified as low-abrasive and are suitable for people with exposed roots or existing wear. A score between 70 and 100 is medium-abrasive, which is acceptable for most users for standard daily cleaning. Formulas exceeding 100 are highly abrasive and may be better suited for occasional use when targeting heavy surface stains.
Factors Influencing Toothpaste Abrasiveness
A toothpaste’s RDA score is primarily determined by the type, shape, and concentration of the abrasive materials added to the formula. Abrasives are included intentionally to help physically remove plaque, debris, and surface stains from the teeth. Common abrasive agents include hydrated silica, calcium carbonate, and dicalcium phosphate.
Hydrated silica is widely used because its particle size and shape can be modified to control the final abrasiveness. Generally, a high concentration of large, irregularly shaped particles results in a higher RDA score. Conversely, finer, more polished particles act as gentle polishing agents and contribute to a lower score. Whitening toothpastes often contain a greater quantity of abrasive agents to scrub away stains, which increases their RDA value compared to standard formulas.
Identifying and Selecting Low RDA Toothpastes
To find the least abrasive toothpaste, consumers should look for products with an RDA score under 70. This range offers effective cleaning while minimizing the risk of wear to the dentin and enamel, especially for those with existing recession or sensitivity. Many toothpastes formulated for sensitive teeth, such as certain gel or clear formulas, are designed to fall within this low-abrasive category.
Unfortunately, manufacturers are not required to print the RDA score on the product packaging, making direct comparison difficult. A reliable way to find this information is to consult publicly available RDA charts compiled by dental researchers or to contact the manufacturer directly. Looking for toothpastes that specifically market themselves for sensitive teeth or enamel protection is also a strong indication of a low-abrasive formulation.
The trade-off that exists with low-abrasive formulas is that they may be less effective at removing heavy, built-up surface stains compared to a high-abrasive whitening paste. Individuals with minimal staining and concerns about wear will benefit most from consistently using a low-RDA product. Sensodyne Pronamel, for example, is frequently cited as a low-abrasive option, often reported with an RDA score below 40.
Minimizing Wear Beyond Toothpaste Choice
While selecting a low-abrasive toothpaste is helpful, it is only one component of preventing dental wear. Mechanical factors related to brushing technique play a significant role in abrasion near the gumline. Using a soft-bristled toothbrush and applying gentle, circular motions rather than aggressive horizontal scrubbing is recommended to protect both the enamel and the gums.
Chemical factors also influence how vulnerable the teeth are to abrasion. Consuming acidic foods and drinks, such as citrus fruits, sodas, and sports drinks, can soften the enamel surface. This softened enamel is more susceptible to being worn away by the mechanical action of brushing, even with a low-abrasive toothpaste. Waiting at least 30 minutes after consuming acidic items allows saliva to naturally begin re-hardening the enamel.
Individuals noticing signs of wear, such as sensitivity or notches near the gumline, should consult their dentist to identify the specific causes and receive personalized guidance.