Cavities are one of the most common chronic diseases worldwide, yet they are largely preventable. The process that creates a cavity is well understood: bacteria in your mouth feed on sugars, produce acid, and that acid dissolves tooth enamel over time. Interrupt this process at any point and you reduce your risk.
This guide covers what works to prevent cavities, what the evidence supports, and what is largely marketing.
How Cavities Form
Your mouth contains hundreds of species of bacteria. Some of these bacteria, particularly Streptococcus mutans, thrive on sugar and produce acid as a byproduct. Every time you eat or drink something containing sugar or starch, these bacteria produce acid that lowers the pH in your mouth.
At a pH below approximately 5.5, enamel begins to dissolve. This is called demineralisation. Your saliva naturally buffers this acid and delivers calcium and phosphate back to the enamel surface (remineralisation). When acid attacks happen faster than your saliva can repair the damage, a cavity forms.
The key insight: it is not just how much sugar you consume, but how often. Sipping a sugary drink over two hours creates a prolonged acid attack. Drinking the same amount in five minutes creates a single, shorter attack that your saliva can manage more effectively.
Step 1: Reduce Sugar Frequency
This is the single most impactful change you can make. Reducing how often you expose your teeth to sugar matters more than reducing the total amount.
Practical steps:
- Drink water between meals rather than juice, soft drinks, or flavoured water
- Eat sugary foods as part of a meal rather than as standalone snacks
- If you drink coffee with sugar, have it in one sitting rather than nursing it over an hour
- Check labels. Many foods marketed as healthy (muesli bars, fruit yoghurt, dried fruit) contain significant sugar
- Brisbane tap water is fluoridated, which makes it a doubly beneficial choice
Read more about sugar and teeth for a deeper look at how different sugars affect decay risk.
Step 2: Brush Effectively, Not Just Often
Brushing twice a day is the standard recommendation, but technique matters as much as frequency. Common brushing mistakes that leave teeth vulnerable:
- Brushing too hard (damages gums but does not clean better)
- Missing the gum line (where plaque accumulates most)
- Brushing for less than two minutes
- Using a back-and-forth scrubbing motion rather than gentle circular or sweeping strokes
Use a soft-bristled toothbrush (manual or electric) and fluoride toothpaste. An electric toothbrush with a timer can help ensure you brush for the full two minutes. Position the bristles at a 45-degree angle to the gum line and use gentle pressure.
For a detailed guide, read how to brush teeth properly.
Step 3: Clean Between Your Teeth Daily
Your toothbrush cannot reach the surfaces between teeth, which is exactly where many cavities develop. Daily interdental cleaning removes the plaque your brush misses.
Options include:
- Traditional string floss
- Interdental brushes (often easier and more effective for people with gaps between teeth)
- Water flossers (helpful for people with braces, bridges, or dexterity issues)
The method matters less than consistency. Choose whichever tool you will use every day. Our flossing guide covers technique for each option.
Step 4: Use Fluoride
Fluoride strengthens enamel by incorporating into the crystal structure, making it more resistant to acid dissolution. It also promotes remineralisation of early damage and inhibits bacterial metabolism.
Sources of fluoride:
- Fluoridated water. Brisbane's water supply is fluoridated, which provides a low-level, continuous exposure that benefits teeth. This is one of the most effective public health measures for cavity prevention.
- Fluoride toothpaste. Use a toothpaste containing at least 1,000 ppm fluoride (standard adult toothpaste in Australia). Spit but do not rinse after brushing, so the fluoride stays in contact with your teeth longer.
- Professional fluoride treatment. Your dentist may apply a high-concentration fluoride varnish during your regular check-up, particularly if you are at higher risk for decay.
Read more about fluoride treatment for adults.
Book a check-up and cavity risk assessment. Call Ivy Dental on (07) 3266 7120 or book online.
Step 5: Address Dry Mouth
Saliva is your mouth's natural defence against cavities. It neutralises acid, washes away food particles, and delivers minerals back to enamel. When saliva flow is reduced (dry mouth, or xerostomia), cavity risk increases significantly.
Common causes of dry mouth include:
- Medications (antidepressants, antihistamines, blood pressure drugs, and many others)
- Mouth breathing
- Dehydration
- Medical conditions (Sjogren's syndrome, diabetes)
- Ageing
If your mouth frequently feels dry, mention it at your next dental appointment. Your dentist may recommend saliva substitutes, sugar-free gum to stimulate flow, or more frequent fluoride applications.
Read our detailed guide on dry mouth causes and treatment.
Step 6: Consider Dental Sealants
Sealants are thin protective coatings applied to the chewing surfaces of back teeth (molars and premolars), where deep grooves and pits trap food and bacteria. They are most commonly placed in children and teenagers, but adults with deep grooves and no existing fillings in those teeth can also benefit.
Sealant placement usually does not require drilling or local anaesthetic, although comfort and appointment time vary. Sealants reduce, rather than eliminate, cavity risk on treated surfaces. Learn more about dental sealants.
What About "Natural" Cavity Prevention?
You may have read about oil pulling, xylitol, hydroxyapatite toothpaste, or dietary supplements as cavity prevention strategies. Here is a brief, evidence-based assessment:
Xylitol. Sugar-free gum containing xylitol may reduce cavity-causing bacteria when chewed regularly. The evidence is supportive but modest. It is a useful supplement to standard hygiene, not a replacement.
Oil pulling. Swishing coconut or sesame oil for 15 to 20 minutes. Limited quality evidence. Not recommended as a substitute for brushing and flossing. Read more in our oil pulling guide.
Hydroxyapatite toothpaste. Emerging evidence suggests it may support remineralisation. Some studies show comparable results to fluoride for early lesions. Not yet endorsed as equivalent to fluoride by Australian dental authorities.
Probiotics. Early research is interesting but not yet sufficient to make clinical recommendations.
None of these approaches replace the fundamentals: reduce sugar frequency, brush with fluoride toothpaste, clean between your teeth, and see your dentist regularly.
How Often Should You Get a Check-Up?
For most adults, every six months. Your dentist can spot early signs of decay (white spot lesions, early enamel breakdown) that you cannot see or feel. Catching problems early means smaller, simpler, and less expensive treatments.
If you are at higher risk for decay, your dentist may recommend three-monthly or four-monthly visits.
At Ivy Dental, we see patients seven days a week at our Everton Park and Nundah clinics. A routine check-up and clean includes examination, X-rays (when due), professional cleaning, and personalised prevention advice.
Call (07) 3266 7120 or book online.
