Dental Caries or Dental Cavity – Cause, Types & Treatment Options

Dental Caries or Dental Cavity – Cause Types and Treatment

Dental caries is a condition which affects a large section of our population. Dental caries is also known as a dental cavity, which is mostly caused due to poor oral hygiene practices.

Some people are more prone to dental caries due to preexisting deep grooves and crevices on the tooth surface. People with misaligned teeth are also prone to dental caries. Sticky sugary food and drinks also increase the likelihood of dental caries.

Depending on location and severity dental caries can be classified into different categories. Let us understand in detail about dental caries or dental cavity.

What is dental caries?

Also known as a dental cavity, or dental cavities, they occur when bacteria living in your mouth make acid that begins to decay your teeth (1). Bacteria in your mouth change the sugar and starches into acids.

The bacteria, acids, food particles and saliva combine to form plaque, which sticks to your teeth usually just above the gum line, within only 20 minutes after eating.

If not removed, this plaque turns into tartar. Both plaque and tartar can irritate your gums, causing gingivitis or eventually periodontal disease. The gums begin to harbor more bacteria.

The acids in plaque damage your enamel, creating cavities in your teeth (2). Untreated tooth decay produces infection, extreme pain and eventually loss of a tooth.

The decay process starts with the unnoticeable damage to the enamel of your teeth and then steadily progresses to dentinal layer, eventually leading to the pulp.

Dental Caries infographic

What causes dental caries?

Poor Oral Hygiene Practices

Poor oral hygiene is the leading cause of tooth decay. This includes irregular brushing, not flossing regularly, not cleaning your tongue, and not using mouthwash. Irregular misaligned teeth make it difficult to clean every surface (3).

Everyone should brush at least twice daily, but it is ideal to brush after every meal. Set a little time while you are brushing to ensure that you brush your teeth covering every area. Improper oral hygiene will ultimately lead to tooth decay which can be easily avoidable.

Deep Tooth Crevices

Individuals who have deep crevices in their teeth are more susceptible to tooth decay. This is because the deep crevices and fissures allow retention of food. This gives access to bacteria and plaque to easily form and produce decay.

Dental sealants also called pit and fissure sealants are used to prevent tooth decay in individuals with deep tooth crevices (4). A dental sealant is effective only for uninfected teeth and is a preventive measure to avoid tooth decay.

Eating habits

Processed food high in sugar and carbohydrates is the leading cause of tooth decay (5). Eating a healthy diet, which includes healthy fruits and vegetables can eliminate the risk of developing tooth decay.

The bacteria in your mouth thrive on the sugary food and produce damaging acid. This can occur several times over the course of meals, and the acid starts producing tooth decay.

Hence it is recommended to brush your teeth after each meal to eliminate this acid. Sticky sugary food like candies stick to the tooth and can cause damage over a prolonged period (6). Avoid any sticky sugary food and also limit snacking in between meals.


Sugary drinks such as juice and soda are also damaging to your teeth. Carbonated beverages such as soda, as well as processed fruit juice,  alter the ph of our mouth (7). These drinks immediately begin to damage tooth enamel with their acid.

Dry mouth issues

Saliva helps inhibit the growth of plaque. Individuals with dry mouth conditions are more likely to dental issues which lead to tooth decay. Certain prescription medications can also cause dry mouth. It may be systemic genetic diseases, diabetes can also cause dental caries (8).

Tooth grinding

Many people have a tooth grinding habit, and they do not even realize that they do this. Tooth grinding typically occurs when a person is asleep or when they are under immense stress.

Tooth grinding leads to tooth decay as it wears the outer layer of tooth enamel (9). Tooth grinding is easily preventable with the use of a bite guard also known as a night guard. Eliminating and preventing stress can also help.


With age, the outer layer of our tooth, the enamel starts to wear off. The inner layer, dentin, is softer than the enamel and more prone to caries (10). The recession of gums with age also makes the tooth susceptible to root caries.

What is the type of dental caries?

G.V. Black Caries Classification

Dr. G.V. Black developed a classification to categorize carious lesions based on the type of tooth affected and the location of the lesion. The six classes of carious lesions are as follows:

Class I

A dental cavity in pits or fissures on the occlusal surfaces of molars and premolars; facial and lingual surfaces of molars; lingual surfaces of maxillary incisors.

Class II

The dental cavity on the proximal surfaces of premolars and molars.

Class III

The dental cavity on the proximal surfaces of incisors and canines that do not involve the incisal angle.

Class IV

The dental cavity on the proximal surfaces of incisors or canines that involve the incisal angle.

Class V

The dental cavity on the cervical third of the facial or lingual surfaces of any tooth.

Class VI

The dental cavity on incisal edges of anterior teeth and cusp tips of posterior teeth.

Caries Classification According to Their Severity

The appearance of interproximal caries can be classified as incipient, moderate, advanced, or severe, depending on the amount of enamel and dentin involved in the caries process.

Incipient caries

Carious lesions which extend less than halfway through the enamel.

Moderate caries

A carious lesion which extends through enamel but does not cross the Dentino-enamel junction. Occasionally food can be stuck in such lesion.

Advanced caries

A carious lesion that extends through the DEJ but does not extend more than half the distance to the pulp. Food particles enter the dental cavity and need to be removed after every meal.

Severe caries

Carious lesion approaching the pulp and which causes sensitivity. A toothache can also develop in relation to such lesions.

Early Childhood Caries

It is also known as baby bottle tooth decay. Early childhood caries, as the name suggests occurs in young children, in the deciduous dentition. It develops when a baby is fed through a milk bottle at bedtime.

A few drops of milk remain in the mouth for a long time resulting in tooth decay. This type of dental caries causes yellowing of the teeth, inflammation of the gums and excessive pain in the teeth causing difficulty in eating, speaking and sleeping.

Usually, it begins in the upper front teeth and gradually involves other teeth. To avoid early childhood caries, night-time breastfeeding and bottle-feeding should be avoided once the first baby teeth begin to appear.

Secondary Caries

The typical locations of occurrence of secondary caries are the edges of restorations and fracture places in the mouth. This type of caries can result from an inappropriate adjustment of restoration or inadequate restoration extension.

For the complete treatment of secondary caries, there has to be complete removal of the original lesion, which may later appear as recurrent caries.

Acute Caries

Acute caries is a rapid process, which affects a large number of teeth. Lesions of acute caries are light brown or grey than the lesions caused by other types of caries.

The caseous consistency of acute caries makes the excavation of the infected teeth difficult. Common effects seen in patients with acute caries are pulp exposure and sensitive teeth.

What are the treatment options?

Pit and fissure sealants

This is a preventive option. Individuals with deep crevices and deep pits and fissures on the tooth surface can seal it, to avoid the risk of developing dental caries.


This is the most widely used restoration material. Composite are tooth-colored material, and it sets by light activation.

Glass ionomer cement(GIC)

It is a cement restoration and has a white appearance. GIC has less strength than other restorative materials, but it has sustained fluoride release properties.


Dental amalgam is an alloy used for restoration in the posterior tooth, which bears high masticatory forces. It is more sturdy than composite and GIC cement, but its appearance makes it a questionable choice.

Zinc Oxide cement

This is mostly used as a temporary restorative material and has low strength. When the cavities turn very deep, caries can extend to the innermost layer, which is the pulp of the tooth. In such case endodontic treatment is required.

How to prevent dental caries?

  • Brush your teeth twice a day
  • Floss daily. Your brushing is not complete without flossing
  • Skip the sugar
  • Swish with mouthwash
  • Use fluoride toothpaste
  • Brush your tongue
  • Pay attention to your mouth and gums
  • Visit the dentist every six months

Over to you

Development of dental caries is easily avoidable. After snacking or eating anything sweet drink water immediately to wash away the acid.

If you already are aware of your dental cavities get them filled at the earliest. Ask your dentist for restoration options and go for the ones indicated by the dentist.

If you have misaligned teeth consider the orthodontic option to prevent the risk of caries. Flossing helps prevent dental caries between teeth. Regular scaling and polishing of teeth prevent plaque buildup on teeth.

Nisha has done BDS. She is a dentist with an inclination towards blogging. Her life is governed by 3 lessons as there is no secret ingredient, everybody has a mission and everyone is meant to do more than what they can.