Dental caries refers to hole or cavity in the teeth due to permanent damage to the hard surface of the teeth. These holes develop gradually and eventually become larger and deeper if not identified and treated early. Though no age grade is exempted, they are common among children, adolescent and older adults.

How Caries Develop

Plaque forms on the surface of teeth as a colourless sticky film. It contains food particles, bacteria and saliva. When the bacteria act on food particle content of the plaque, they convert the sugar content of the food particle into acid. The acid dissolves the mineral content of the enamel of the teeth, thus removing their protective layer and exposing the sensitive part of the teeth to corrosion and bacterial infection. 

Symptoms and Signs of Dental Caries

What someone with dental caries feels depends on the location and size of the cavity at a particular time. At the onset, the individual may not feel anything. This is because the hard layer of the teeth (enamel) is affected first. This layer is not sensitive and so the affected person does not feel pain. As the cavity gets larger and deeper, any of the following or a combination of them may be felt. They include:

1. Toothache occurring while eating, chewing and drinking cold or hot liquid (such as water).
2. Persistent toothache resulting in headache.
3. Black or brown stain on teeth.
4. Visible hole in the teeth.

Treatment of Dental Caries

Treatment option depends on how severe the cavity is. It could be any of the following:

1. Fluoride treatment – This is useful for early tooth decay which only involves demineralization of the teeth. Applied to the teeth in form of a gel, it helps to restore the enamel of the teeth and may reverse cavities in the early stage. This fluoride makes the enamel more resistant to acid produced by the bacteria in plaque.
2. Fillings (restorations) – Fillings are used for cavities that have progressed beyond the earliest stage, involving hole in the enamel. They are used to fill the defects / cavities in the affected teeth. The materials used have the same colour as the teeth.
3. Crowns – A crown is necessary when there is extensive damage to the teeth, involving the dentine (the layer of the teeth under the enamel). It replaces the natural crown of the teeth. To fit well, the decayed area is drilled away with some parts of the normal area, enough to accommodate the replacement crown. These crowns are made of materials that are resistant to corrosion.
4. Root canals – This method is used when the hole in the teeth has reached the innermost part (the root canal); and in some cases, with abscess formation. It is used as an alternative to extraction (removal) for badly damaged or infected teeth. It involves removal of the infected pulp, treatment of the root canal, replacement of the pulp with a filling and placement of a crown on the affected tooth. 
5. Tooth extraction – This method is used for severely damaged teeth (possibly with abscess / pus formation) which cannot be treated by other methods. The tooth removed can be replaced by a dental implant in order to avoid having a gap between the teeth which may make them shift. Antibiotic treatment may be necessary to kill the bacteria. 

Prevention of Dental Caries

Good oral (mouth) hygiene is central to preventing tooth decay. This can be achieved by:

1. Regular brushing of teeth – It is recommended that teeth are brushed, at least, twice a day. In addition to this, teeth should be brushed after every meal. This helps to remove every food remnant, which bacterial may act on, from the teeth.
2. Use of fluorinated tooth paste – Fluorine helps strengthens the teeth against corrosion.
3. Reduction in intake of sugary substances – These include sweets, biscuits, energy drinks. These substances leave high quantity of sugar on the teeth for bacteria to act on and convert to acid.