[Reading Science] 'Does Drinking Cola Cause Tooth Decay?' It Was True Then, But Not Now

KAIST-Seoul National University Researchers Demonstrate Prevention Method for Tooth Decay Using Nanotechnology

Carbonated beverages like cola are loved by many. However, carbonated drinks have long been criticized for threatening not only obesity but also dental health. Cola, which combines acidity and sugar, is known to erode tooth enamel, leading to cavities and tooth damage.

There are ways to protect your teeth even while drinking cola. Using a straw can reduce the time cola directly contacts the teeth. Rinsing your mouth with water after drinking cola can help neutralize some of the acidity. However, these methods alone are insufficient.

Recently, sugar-free "Zero Cola" has gained popularity, but concerns about tooth damage remain. In this context, researchers from KAIST and Seoul National University have scientifically demonstrated an effective method to prevent tooth erosion caused by cola using nanotechnology, drawing significant attention. On the 5th, KAIST announced that Professor Hong Seung-beom’s team from the Department of Materials Science and Engineering, in collaboration with Seoul National University’s School of Dentistry, discovered that Silver Diamine Fluoride (SDF), widely used as a dental treatment for cavities, forms a protective film on the tooth surface that prevents tooth erosion. This study not only confirmed the effectiveness of SDF but also analyzed the process at the nanoscale, presenting a more detailed mechanism.

(From left) Professor Seungbeom Hong, Department of Materials Science and Engineering, KAIST; Aditi Saha, PhD candidate; Professor Hyeryeong Byun, Department of Chemistry; Professor Gakgyun Kim, Seoul National University School of Dentistry. Photo by KAIST

SDF is a dental agent used for the prevention and treatment of cavities. It forms a thin protective film on the tooth surface, shielding teeth from acidic environments and bacteria. SDF strengthens cavity-affected areas, inhibits bacterial growth, and effectively halts the progression of cavities.

The research team revealed that SDF forms a protective layer called fluoroapatite on the tooth surface. Fluoroapatite is an inorganic mineral similar to the components of tooth enamel and effectively protects teeth in acidic environments. The team used Atomic Force Microscopy (AFM) and X-ray Photoelectron Spectroscopy (XPS) to precisely observe the chemical and physical changes on the tooth surface before and after SDF treatment.

Experimental results showed that teeth treated with SDF exhibited almost no change in surface roughness and maintained stable elastic modulus even when exposed to cola. In contrast, untreated teeth showed surface roughness increasing by more than three times and elastic modulus dropping to one-fifth within five minutes, clearly indicating the effects of erosion. This is attributed to the protective film formed by SDF on the tooth surface effectively defending against the acidity of cola.

The achievement by KAIST and Seoul National University researchers is regarded as a significant turning point in the field of tooth erosion prevention. While conventional dental treatments mainly relied on surgical methods to address cavities and erosion, SDF demonstrates effectiveness through a non-invasive approach. Applying SDF is a simple procedure that can greatly reduce pain and costs while effectively strengthening teeth.

The KAIST research team emphasized, "Dental health is closely linked not only to aesthetics but also to an individual's overall quality of life," adding, "This research outcome has great potential for broad application in dental treatment." The study was supported by the National Research Foundation of Korea and published in the international journal Biomaterials Research.

Professor Hong stated, "Dental health is a crucial factor directly connected to quality of life," and explained, "This study demonstrated the potential to prevent early tooth erosion through a non-invasive method." Professor Kim Young-jae of Seoul National University’s Department of Pediatric Dentistry evaluated, "This technology using SDF will become an effective and accessible dental treatment for both children and adults."

The negative impact of cola on teeth is not merely a folk remedy story. Highly acidic cola erodes the enamel on the tooth surface, promoting the proliferation of cavity-causing bacteria. The pH of a glass of cola is about 2.5, which is over 1,000 times more acidic than neutral water with a pH of 7. In such an environment, tooth surface damage can occur within minutes. In experiments by the KAIST research team, the surface roughness of teeth exposed to cola sharply increased within just 10 minutes.

Alongside domestic research achievements, overseas studies to protect dental health are actively underway. A study in the UK reported that milk proteins play an important role in preventing tooth erosion. Proteins found in dairy products such as milk and cheese neutralize acids that cause cavities, thereby protecting teeth. Additionally, research in the United States emphasized that fruit juices can also cause tooth erosion and warned against excessive consumption.

Acidic beverages like cola and fruit juices should be consumed in moderation to reduce their negative effects on dental health. Experts recommend avoiding brushing teeth for at least 30 minutes after drinking such beverages, instead rinsing the mouth with water and waiting before brushing. This allows the weakened tooth surface in the acidic environment time to recover.