Tooth decay is the destruction of your tooth enamel, the hard, outer layer of your teeth & produced by oral bacteria. There exists an active relationship between sugars and oral health problems. Consumed sugar may occur naturally or be an additive. A multiple of factors in addition to sugar affect the tooth decay process. These include type of food and duration of exposure but sugar is the cornerstone of tooth decay. Medical research has shown a direct link between dietary sugar and tooth decay (dental caries).

Tooth decay has a huge financial and social burden. Tooth decay is common in developed nations due to the sugar-rich diet prevalent in those countries. The treatment cost of tooth decay accounts for 10% of total public health care expenditure in European countries. Tooth decay is characterised by destruction of the tooth enamel; it involves presence of oral bacteria and a sugar-rich diet. The degree of tooth decay is affected by the level of oral hygiene and genetic factors. Preventing tooth decay needs to focus on eliminating or minimising sugar consumption apart from having regular dental checkups.      

Examples of sugar-rich foods and drinks are:

  • Confectionary        
  • Cakes       
  • Biscuits      
  • Sweetened cereals       
  • Sweet desserts       
  • Sucrose       
  • Honey       
  • Sugar-sweetened beverages
  • Fruit-based and milk-based sweetened drinks.         

Studies linking tooth decay to dietary sugar come from:

  • Human intervention studies
  • Human  observational studies
  • Animal studies
  • Plaque pH experiments
  • Enamel slab experiments       

When you consume sugar it reacts with bacteria present in the dental plaque. This bacterial for example Streptococcus metabolises sugar to produce organic acids.    

 The ideal pH for normal teeth health is above 5.5. The organic acids produced from metabolism of sugar makes the pH of the teeth environment to fall below 5.5. This in turn causes demineralisation of the enamel leading to tooth decay.   

It is important to note that saliva offers a protective biological fluid in the oral cavity. This produces a buffer to any raise in pH level that may lead to demineralisation of the enamel and eventual tooth decay. Buffering action of saliva is on the surface of dental plaque. But dietary sugar produce acid high acid levels that the buffering effect of saliva cannot contain. Organic acids produced from metabolism of sugar diffuse faster to reach dental plaque and cause tooth decay. The higher the concentration of sugar present, the faster the rate of diffusion and hence the more tooth decay experienced.  

 In contrast, a low sugar diet favors remineralisation of the enamel hence helps prevent tooth decay. Sugar contains sucrose which increases colonisation of the teeth by Streptococcus bacteria thus increasing tooth decay.   

 Tooth decay is characterised by painful and sensitive teeth. Sensitivity may be experienced during biting or drinking cold/hot drinks. When tooth decay is not managed in time it leads to formation of cavities that expose the tooth pulp to bacterial infection. If this occurs, your dentist will give you a root canal treatment or extract the tooth if it’s extensively decayed.        Prolonged tooth decay leads to periodontal disease (gingivitis/gum disease). This is properly managed through good oral hygiene.

Advanced gingivitis will require dental treatment to prevent permanent teeth loss.   Children are more susceptible to tooth decay than adults; this is because their teeth are still growing hence the enamel is soft and easily corroded.      


In order to prevent tooth decay the following tips would help a great deal. Use fluoride toothpaste irrespective of whether you live in a fluoride-rich area or not. Eliminate or limit the amount and frequency of sweet drinks in order to minimise tooth decay. Don’t sip sugar sweetened drinks, instead drink it. Brush and floss your teeth twice daily. Visit your dentist regularly for checkups. Restrict the amount of sugary foods eaten and keep it to meal times rather than in regular snacks.

Chew sugarless gum between meals to increase saliva. Eat dairy foods like cheese after consuming fermented carbohydrates and others sugars. Refrain from putting a child to bed, with a feeding bottle having sugar-sweetened beverage or milk. Encourage a child to sip water in between meals to encourage saliva production.

You can help protect your oral health by seeing your dentist regularly for checkups every 6-12 months. Our teeth whitening packages in Sydney can also include a dental check-up. View our packages here.