Causes and Effective Prevention
By Dr. Adrian Cano, DDS, Specialist in General Dentistry & Owner of Züri Zahni Dental Practice
Tooth decay is the most common infectious disease worldwide – but how exactly does it develop, and what can you do about it? In this article, you’ll learn how cavities form, how diet plays a role, and what measures you can take to keep your teeth healthy in the long term.
How does cavity develop?
Tooth decay, or dental caries, occurs when four key factors come together:
- A host – the person, or more specifically, their oral cavity
- Bacteria – which settle in dental plaque and food debris
- Sugar – as a food source for these bacteria
- Time – the longer sugar stays in the mouth, the greater the risk
The bacteria in our mouths metabolize sugar and produce acids. These acids attack the enamel and dentin, dissolving calcium and phosphate in a process called demineralization.
The difference between an initial lesion and advanced tooth decay / cavity
- Initial lesion: At this early stage, minerals have already been lost from the enamel, but the surface remains intact. It’s not yet a cavity and can often be reversed through fluoride use and improved oral hygiene. It typically appears as a white or chalky matte spot on the tooth surface.
- Advanced lesion: Once the tooth structure is weakened enough for the surface to collapse, a cavity forms. The crystalline structure is damaged, and remineralization is no longer possible. Bacteria become embedded in the cavity and can no longer be removed by regular brushing. As the lesion progresses, the chewing surface loses stability and breaks down, resulting in a visible hole with dark or brown discoloration.
Why untreated tooth decay / cavity is problematic
If left untreated, decay progresses quickly into the dentin, which is softer than enamel and contains many dentinal tubules – tiny channels leading to nerve endings. These tubules act like highways for bacteria on their way to the pulp (the tooth’s nerve).
That’s why cavities can cause pain: when bacteria reach the nerve, it leads to pulp inflammation and infection. At that point, only a root canal treatment or tooth extraction may be able to resolve the issue.
The impact of diet on tooth decay / cavity
It’s not just the total amount of sugar consumed that matters – the frequency of sugar intake throughout the day plays a crucial role. Every time sugar is consumed, acid production begins and attacks the enamel. Frequent sugar consumption can also harm the body overall and has addictive potential. That’s why it’s best to limit sugar as much as possible.
Think of frequent sugar intake like a fire that never goes out: constant snacking fuels continuous acid production. Avoiding sugar allows the pH level in the mouth to recover. Fluoride toothpaste acts like a fire extinguisher – strengthening enamel and supporting remineralization.
Tips to Reduce the Risk of Tooth Decay
- Limit sugar intake: Watch out for hidden sugars in processed foods and choose low-sugar alternatives.
- Drink water instead of sugary beverages: Water helps neutralize acids in the mouth. Sugar-free options like unsweetened teas or zero-sugar drinks can also be good choices.
- Brush teeth right after meals: While it was once advised to wait after eating, new studies show that brushing regularly after every meal is more important.
- Avoid sipping sugary drinks throughout the day: Juice, soft drinks, and sweetened coffee cause continuous acid attacks on the teeth.
How can remineralization be supported?
- Maintain good oral hygiene and remove bacteria: Regular brushing and cleaning between the teeth with floss or interdental brushes reduce bacterial buildup and make the surface more accessible to fluoride.
- Chew sugar-free gum with the “tooth-friendly” symbol: This stimulates saliva flow, which helps transport minerals back into the tooth structure.
- Eat calcium-rich foods: Dairy products, leafy green vegetables, almonds, sesame seeds, small fish with bones (like sardines), and legumes help strengthen teeth and support remineralization.
- Use fluoride products: Fluoride toothpaste and fluoride gels strengthen enamel and aid mineral uptake.
- Try xylitol as a sugar alternative: Xylitol fights cavity-causing bacteria by entering and destroying their cells. However, excessive intake can cause digestive issues, so it should be used in moderation.
- Avoid sticky foods and snacks between meals: These tend to stick to the teeth and provide bacteria with ideal conditions to produce acid.
Why is the risk of tooth decay higher at night?
During sleep, the body produces less saliva, which normally helps clean and protect the teeth. This is especially important for young children—nighttime breastfeeding or bottle-feeding with milk, chocolate milk, or formula can be harmful. The liquid stays on the teeth and acts undisturbed overnight.
Tip: After brushing in the evening, only water should be consumed.
Reminder: Good oral hygiene is key to prevention
- Brush regularly with fluoride toothpaste.
- Don’t forget between your teeth! Use interdental brushes or floss to remove hidden plaque.
- Regular dental check-ups help detect and treat tooth decay early.
Conclusion
Tooth decay is the most common infectious disease and is caused by acid-producing bacteria that metabolize sugar and attack the enamel. The frequency of sugar intake is just as important as the amount. A healthy diet, good oral hygiene, and promoting remineralization are key to keeping your teeth healthy. Through mindful eating, regular brushing, and routine dental visits, you can effectively prevent cavities and protect your dental health in the long term.
Dr. med. dent. Adrian Cano & the Züri Zahni Team
