Dental Decay

How to assess risk of dental decay and what can be done to prevent it?

What is dental decay?

Dental decay is an infection process which occurs through an interaction between bacteria and carbohydrates in the oral cavity, and if left untreated, leads to pain and tooth loss. It is one of the most common of diseases, coming only second to the common cold. Dental decay begins as bacteria attach themselves to the thin film that coats the surface of teeth over time due to ineffective oral hygiene practices. These bacteria interact with sugar in the diet, releasing acid which leads to demineralisation of the tooth structure and may be visible on the tooth as a small white spot. A buffering action of the saliva leads to eventual remineralisation, thus this can be described as a dynamic process of the two.

Risk assessment:

Each patients risk assessment varies and is determined by the patients history, their oral hygiene practices, habits, medical history and these are then put in line with their needs and preferences. While plaque and calculus are the basic risk factors of periodontal disease, some individuals with large amounts of plaque may still not have periodontal disease.

The dental decay imbalance model highlights three important risk factors:

  • Acidogenic, Gram negative bacteria
  • Salivary function
  • Habits, including amount of sugar consumption, smoking, poor oral hygieneThe microbial flora of an individual’s mouth is a big determinant in this progression, with Streptococcus Mutans and Lactobacili being predominant. There is a positive correlation between these bacteria and plaque biofilm accumulation. These bacteria interact with the tooth structure leading to eventual demineralisation and if it is not countered by remineralisation, cavitation results.The protective function of saliva helps get rid of the acidic environment in the mouth induced by eating sugary foods and inadequate salivary production induces dental decay. Salivary function can be assessed by history taking, or chair side tests to evaluate salivary flow, consistency and buffering capacity of the saliva.Diet is directly linked to the PH of the mouth. Salivary enzymes break down carbohydrates and lower the PH.


Protective action can be taken in several ways to arrest dental decay and prevent gingivitis and periodontitis incurred by it.
Basic preventive measures include dietary modifications, patient education, good oral hygiene practices which induce plaque removal like anti-bacterial mouth rinses, regulation of salivary flow, use of sugar-free xylitol gums.

While efficient brushing and oral hygiene are routine dental practices to be incorporated, a few additional ways to combat dental decay are as follows:

  • Topical fluoride application – low doses are effective and have a protective action against decay
  • Pits and fissure sealants to prevent plaque accumulation in deeper areas, which are also more decay prone.
  • Anti microbial agents including chlorhexidine rinses, and varnishes to balance the microbial flora of the mouth and neutralise the pH.The strategy used for each patient is focused to the patients need but it’s important to identify high risk individuals after careful oral examination and history taking. For low risk patients, education and remineralisation should be considered whereas for high risk patients, dental intervention must be done to stop progression of decay.