Sodium bicarbonate, commonly known as baking soda, has been used as a traditional household item for cleaning and as an ingredient in do-it-yourself dental remedies for generations. This practice often stems from its ability to neutralize odors and gently scrub surfaces. A frequent concern surrounding its use for oral hygiene is the possibility that this abrasive powder might physically damage the protective layer of tooth enamel. Understanding the true risks requires a closer look at the structure of the tooth and the scientific methods used to measure dental product safety.
Understanding Tooth Enamel
The outer layer of the tooth, known as enamel, is the hardest substance in the human body. Its composition is nearly entirely mineral, consisting of approximately 96% hydroxyapatite, a crystalline calcium phosphate structure. This highly mineralized shell is designed to withstand the pressures of chewing and act as a barrier against the oral environment.
Despite its strength, enamel is susceptible to two primary forms of wear that can lead to permanent damage. Abrasion is the physical wearing away of the tooth structure by friction, often caused by a toothbrush or abrasive particles. Erosion is the chemical dissolution of the mineral content caused by acids from foods, drinks, or stomach reflux. Once enamel is lost, the body cannot regenerate it.
Measuring Abrasiveness in Dental Products
The potential for a dental cleaning agent to cause physical wear is quantified using the Relative Dentin Abrasivity (RDA) scale. This standardized laboratory test measures the amount of wear a product causes to dentin, the softer material underneath the enamel, under controlled brushing conditions. The resulting RDA value provides a reliable metric for comparing the abrasiveness of different toothpastes and powders.
The RDA scale typically ranges from 0 to 250, with higher values indicating greater abrasivity. Products scoring below 70 are classified as low abrasive and are considered safe for daily use. Standard commercial toothpastes usually fall between 70 and 130. Highly abrasive whitening products can reach the upper limit of 250, which is the American Dental Association’s recommended maximum.
How Baking Soda Interacts with Enamel
Contrary to the common fear that it is too harsh, baking soda is among the least abrasive cleaning agents used in dental care. Plain sodium bicarbonate powder has an extremely low RDA value, typically around 7, which is only slightly higher than brushing with plain water (RDA of approximately 4). This low abrasiveness is attributed to the fine, soft structure of the crystals, which are also highly soluble and dissolve quickly during brushing. When dissolved by saliva and water, the abrasive particles rapidly lose their sharp edges, making the physical scrubbing action mild and gentle on the tooth surface.
Beyond its physical properties, baking soda provides a chemical benefit due to its alkaline nature. It helps to neutralize acids in the mouth by increasing the pH level, acting as a buffer against acidic challenges. Since acid is the primary cause of chemical erosion, this neutralizing effect helps to reduce the risk of demineralization. By shifting the mouth’s pH toward a neutral state, baking soda supports an environment where natural remineralization can occur.
Safe Practices for Using Baking Soda
To incorporate baking soda into a dental hygiene routine safely, attention should be paid to application technique. It is important to ensure the powder is fully dissolved into a paste with water before applying it to the toothbrush. Applying dry powder or using excessive amounts can increase the potential for abrasion.
While baking soda offers unique benefits, it should not fully replace a fluoride-containing toothpaste. Fluoride is scientifically proven to strengthen enamel and aid in the remineralization process. A soft-bristled toothbrush should always be used, as the mechanical action of the brush itself is often the greater source of abrasive wear. Using baking soda in moderation as a supplement allows a person to gain its cleaning and pH-balancing benefits.