Dental Caries : An Overview by Dr. Upasana Venaik

Oct 18, 2020

Dental hygiene and oral health are essential parameters but we tend to ignore them. Before we start on topics about how to practice good oral hygiene, it is important to understand what dental caries means.


Dental caries is a sugar dependent multifactorial, acid produced infectious disease, which is a byproduct of the metabolism of dietary carbohydrate by mouth bacteria resulting in a drop of pH level on your tooth surface.

Normally there is a fine balance between acid and alkali, therefore the pH is maintained near neutrality (6.7 – 7.3). As the pH in the mouth drops, which generally happens after intake of sugary food or drink, the acidic environment in the mouth stays for a longer duration. Due to this, calcium and phosphate ions diffuse out of the enamel (which is the outermost, protective covering of the tooth) resultingin demineralization. This process is reversed when the pH rises again. Dental Caries is therefore a dynamic process that is characterized by an episode of demineralization and remineralization occurring over time. If the dissolution of minerals predominates, cavitation occurs.

Three layers of the Tooth:

Enamel:The outermost layer is the strongest layer and is white-colored, made up of calcium, phosphate minerals and this is the layer of the teeth that you normally see when you smile. It is known as the Enamel.


Dentin: The middle layer is known as Dentin. It is not as strong as the Enamel and is yellowish and also sensitive if exposed.

Pulp:The innermost layer which forms the core of the tooth and is surrounded by the Enamel and Dentin is Pulp. The Pulp holds all the blood and the nerve supply of the tooth, implying that all the sensation that a tooth feels after eating hot or cold food is present in this layer. This makes it the most vulnerable part of the tooth if exposed due to caries.

Enamel being the hardest layer protects these underneath layers and thereby helps in chewing and enjoying the food we eat.

If the outermost layer of the Enamel is destroyed and the Dentin layer gets exposed, the caries progression is really fast. If the innermost core of the tooth gets involved,it can lead to infection causing unbearable pain and pus. The progression of caries depends upon the condition inside the mouth. If a person has no or very little sense of oral hygiene, then the carious lesion will progress very fast but if a person keeps a constant check on their oral hygiene, then the caries progression can be really slow.

Susceptible Sites on a Tooth

 Susceptible sites are the sites which are prone to decay. On these sites is where the food accumulation can occur easily, for example, proximal enamel surfaces (surfaces adjoining two teeth), cervical margins and pits and fissures (top surface of the tooth).


Saliva plays an important role in the progression of caries. It acts as an intraoral antacid due to its alkaline pH at a high flow rate and buffering capacity also decreases food accumulation and aids in the clearance of foodstuff. Saliva is a reservoir of calcium phosphate and fluoride ions thereby favoring mineralization. It also has an antibacterial action because of its enzymes content.

Caries Prevention

Classically three main approaches are possible:

  1. Tooth strengthening or protection
  2. Reduction in the availability of microbial substrate    
  3. Removal of plaque by physical or chemical means

In practice, this means dietary advice, fluoride, fissure sealing, and regular tooth brushing(which is also important in the prevention of gum disease).

The relative value of these varies with the age of the individual.

Recall Intervals

 The dental recall of a patient depends upon the risk assessment of existing disease of progression or new disease developing.

●     For healthy patients, the interval is once a year, but a person at higher risk often needs to be seen more frequently.

●     For adult patients, this interval can be anywhere between 3 and 24 months.

●     Forchildren the interval between 3 and 12 months.

 A child's first checkup should occur once the first teeth have erupted (that is usually between six months and one year of age). Oral hygiene is one of the important parameters for good quality of life. Make sure you and your children practice it thoroughly.