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Preventing Tooth Decay

What is Tooth Decay?


Tooth decay occurs when sugar in food and drinks reacts with the bacteria in plaque (the thin sticky film on your teeth), resulting in the formation of harmful acids. Theses acids attack the teeth and destroy the enamel and dentine of a tooth. After this happens many times, the enamel may break down, forming a hole or 'cavity' in the tooth. If the cavity is small it can usually be repaired with a filling.  As the cavity gets bigger it can lead to toothache and even an abscess, which may require a root canal treatment or even extraction.

What Causes Tooth Decay?

Sugary Diet

  • Eating food and drink rich in sugar causes the formation of plaque acids which can attack the teeth and so increases the risk of tooth decay.

  • It is not just the amount of sugar you consume, but more importantly how frequently you consume sugar. This is because the acid attacks only last for an hour after eating or drinking, before the natural salts in your saliva cause the enamel to ‘remineralise' and harden again. So if you only consume sugar occasionally, tooth decay will not have a chance to progress, but if you consume it frequently throughout the day, this will significantly increase the number of acid attacks, and so the teeth are much more likely to decay.

  • It's not just refined sugars in obvious things like fizzy drinks, sweets, chocolates, cakes etc that are harmful: other types of carbohydrate containing foods and drinks react with plaque and form acids. These are the ‘fermentable' carbohydrates: for example ‘hidden sugars' in processed food, natural sugars like those in fruit and cooked starches.


Poor Oral Hygiene

  • Not cleaning your teeth thoroughly will increase plaque build up and therefore can lead to tooth decay.

  • Plaque build up in between the teeth, on the biting surfaces of the teeth and by the gum poses the highest risk of tooth decay.

Dry Mouth

  • People who have lower levels of saliva in their mouth are at higher risk of developing tooth decay, because saliva helps to remineralise teeth after a sugar acid attack.

  • A number of medical conditions and medications can cause dry mouth.


  • Smokers have a higher chance of developing tooth decay as tobacco smoke interferes with the production of saliva, which helps to remineralise teeth after a sugar acid attack.

How do you Prevent Tooth Decay?

Healthy Diet

  • Avoid sugary foods and drinks such as fizzy drinks, tea/coffee with added sugar, sweets, chocolates and cakes. Avoid starchy foods containing high levels of carbohydrate such as crisps, white bread & biscuits.

  • Healthier alternatives include fruits and vegetables, cheese, nuts, and unrefined carbohydrates  such as wholemeal or brown bread, rice, pasta, potatoes and eggs.

  • Avoid  snacking in between meals. It's not just the amount of sugar you eat or drink, but also how often you consume it. It is better for your teeth to have 3 meals a day plus no more than 2 snacks, rather than having lots of snack attacks. If you do have a snack between meals, choose foods that don't contain sugar such as cheese, raw vegetables, nuts and breadsticks​​​​​​


Chewing Sugar-free gum

  • Chewing sugar-free gum for twenty minutes,  after you have eaten also helps prevent tooth decay. When you chew gum, your mouth produces saliva, which neutralises the acid in your mouth before it can damage your teeth.

  • Chewing gum containing xylitol, a natural sweetener, further helps to reduces tooth decay.

Fissure Sealants

  • One of the most common areas for tooth decay to occur is in the small grooves (fissures) on the biting surfaces of the back teeth.

  • Fissure sealants are protective plastic coatings that the dentist applies to these surfaces.

  • The sealant forms a protective barrier that stops food and bacteria getting into the fissures  thereby helping to prevent tooth decay occurring in these sites.

  • They are normally applied in children who are at high risk of tooth decay


Fluoride toothpaste and fluoride mouthwash

  • Fluoride helps to strengthen teeth, and protects them from tooth decay

  • You should brush your teeth thoroughly with a fluoride toothpaste for 2 minutes twice daily.

  • Children up to 3 years old, should use a smear of toothpaste with a fluoride level of no less than 1000ppm (parts per million).

  • Children aged  3 to 6 years old, should use a pea- sized amount of toothpaste that contains 1350ppm - 1500ppm fluoride.

  • Adults should use a toothpaste that contains at least 1450ppm fluoride.

  • Some patients who have a high risk of developing  tooth decay, may be advised by their dentist to use a toothpaste with an even higher level of fluoride

  • Using a fluoride mouthwash containing 225ppm fluoride, on a daily basis, can also help to prevent tooth decay. The mouthwash should not be used directly after toothbrushing, but at a different time, such as after lunch. You should avoid eating or drinking for at least 30 minutes after using a fluoride mouthwash. Mouthwash is not suitable for children under 7 years of age.


  • How long to brush for: You should brush your teeth thoroughly for 2 minutes twice a day.

  • When to brush: The best time to brush is in the morning before breakfast and last thing at night before you go to bed. Avoid brushing straight after a meal as it can damage your teeth, especially if  you've had fruit, fizzy drinks, wine or any other foods that contain acid.

  • Manual or electric: tests have shown that electric brushes are more effective at removing plaque than manual brushes. They are particularly useful for people with limited movement, such as disabled or elderly people who find it difficult to clean thoroughly with a manual brush. It is however possible to brush effectively with a manual brush as long as a good technique is employed.

  • Use a brush with a small to medium-sized head, small enough to reach into all parts of the mouth.

  • It should have soft to medium multi-tufted bristles. Hard-bristled brushes should be avoided as they can cause the tooth enamel to be worn away.

  • Brushing technique

    • Place the head of your toothbrush against your teeth, then tilt the bristle tips to a 45 degree angle against the gumline. Move the brush in small circular movements (for manual brushing).

    • Brush the outer surfaces of each tooth keeping the bristles angled against the gumline.

    • Use the  same method on the inside surfaces of all your teeth.

    • Brush the biting surfaces of the teeth.

    • To clean the inside surfaces of the front teeth, tilt the brush vertically and make several small  circular strokes with the front part of the brush.

Interdental cleaning

  • It is important to clean in between your teeth at least once a day using either interdental brushes or dental floss

  • Interdental brushes are good for wide gaps in between your teeth, or if you find flossing difficult. They come in different sizes for different sized gaps.

  • Flossing is good for narrower gaps where teeth are closer together. Correct flossing technique:

  • Break off about 18 inches of floss, and wind most of it around one of your middle fingers. Wind the remaining floss around the middle finger of the other hand.

  • Then hold  the floss tightly between your thumb and forefingers, with about an inch of floss between them, leaving no slack.

  • Use a gentle 'rocking' motion to guide the floss between your teeth.

  • When the floss reaches the gumline, curve it into a C-shape holding it against the side of one of the teeth in the gap. Gently scrape the side of the tooth, moving the floss away from the gum. Repeat on the other side of the gap, along the side of the next tooth.

  • Flossettes are an alternative to flossing which many patients find easier to use. They consist of a piece of floss on a small plastic handle.

Regular Dental visits

  • It is important to visit the dentist regularly for check-ups  - your dentist will advise you as to how often you need to attend.

  • If you are at low risk of developing tooth decay you may only need to come once every 1 - 2 years. However if you are at higher risk they may suggest you visit as frequently as every 3 months.

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