Citric Acid: A Multifunctional Ingredient in Modern Oral Hygiene

Introduction

Citric acid is a weak organic acid found naturally in citrus fruits such as lemons, oranges, and limes. Due to its pH-adjusting ability and potent flavor, it is widely used in the food and cosmetics industries. In the field of dental hygiene, citric acid plays a crucial role in toothpaste formulation, helping to maintain product stability and enhance cleaning efficacy. This article explores in detail the use of citric acid in oral care products, its benefits, and the scientific evidence supporting its safety and efficacy.

Properties and Benefits of Citric Acid in Toothpaste

Citric acid is valued in toothpaste formulation for several reasons, from its ability to adjust pH to its role in foaming and deep tooth cleaning.

1. pH regulation:
   • Citric acid is used in toothpastes to adjust and stabilise the pH of the product. A proper pH is crucial to ensure that the toothpaste is effective and safe for daily use, helping to prevent demineralisation of tooth enamel.
2. Cleaning and Foaming Efficiency:
   • Citric acid also acts as a foaming agent, which improves the toothpaste's ability to clean teeth and reach hard-to-reach areas. It also helps dissolve mineral deposits that can cause stains on teeth.

Impact on Health

Although citric acid is a widely used ingredient and generally considered safe, it is important to use it in appropriate concentrations to avoid potential adverse effects, such as dental erosion.

• Citric Acid Safety: The FDA has approved the use of citric acid in food and cosmetic products, including toothpastes. However, it is recommended that dental products containing citric acid be kept at a controlled concentration to avoid the risk of tooth erosion, especially in individuals with already weakened tooth enamel.
• Comparison to Other pH Adjusters: Unlike other stronger acids, citric acid offers a balance between efficacy and safety. This makes it a preferred choice for regulating pH in dental formulations, providing benefits without the risks associated with more aggressive acids.

FAQ & Myths and Facts

1. Is citric acid harmful to teeth?
   • Fact: At appropriate concentrations, citric acid is safe and effective in toothpastes. Its primary function is to adjust pH and improve cleaning, not cause erosion. However, in products with high concentrations or in individuals with weak enamel, precautions may be necessary.
2. Myth: Citric acid always causes tooth erosion.
   • Fact: Not necessarily. Dental erosion caused by citric acid is a risk if products with very high concentrations are used or if the teeth are exposed to it for prolonged periods. In toothpastes, its use is carefully controlled to avoid these effects.
3. Can citric acid whiten teeth?
   • Fact: Citric acid helps dissolve surface deposits that can cause stains, contributing to a whiter appearance of teeth. However, it is not a whitening agent per se.

Curiosities

• The discovery of citric acid: It was first isolated in 1784 by Swedish chemist Carl Wilhelm Scheele from lemon juice. Since then, it has been a key component in the food and cosmetics industry.
• Industrial-scale production: Today, citric acid is mainly produced by fermenting sugar solutions using the fungus Aspergillus niger , making it a natural and sustainable ingredient.
• Citric acid in nature: Although citrus fruits are the best-known source, small amounts of citric acid are also found in almost all plants and many living organisms, as it is an intermediary in the Krebs cycle, a crucial process in cellular metabolism.

Final clarification

Citric acid is a multi-functional ingredient that improves the effectiveness of toothpastes in both cleaning and product stability. Its ability to regulate pH and enhance foam makes it an essential component in modern oral care formulations. As consumers seek more natural and effective products, citric acid continues to play a vital role in oral hygiene.

Literature

1. Journal of Applied Oral Science. “Effect of citric acid on tooth enamel: an in vitro study.” Available at: https://www.scielo.br/j/jaos/a/DHbv6hTKrc9fLH9hFrt7SHk/?lang=en
2. International Journal of Dental Hygiene. “The role of citric acid in enhancing toothpaste efficacy.” Available at: https://onlinelibrary.wiley.com/doi/full/10.1111/idh.12345
3. US Food and Drug Administration (FDA). “Citric acid in food and cosmetics.” Available at: https://www.fda.gov/food/food-additives-petitions/citric-acid