What is Tooth Decay?
Tooth decay (cavities or dental caries) happens when acid formed by bacteria in plaque on the teeth damages the enamel. Sweet foods and drinks and poor dental hygiene contribute to this condition.
It is reported that almost 100 percent of adults worldwide will have tooth decay at some point. It also affects between 60 to 90 percent of school age children. (1)
This condition can cause pain, harm your teeth and eventually lead to tooth loss.
Symptoms
Teeth are made up of three layers. The hard outer layer which is visible is called the enamel. Beneath this is a softer substance similar to bone called dentin. These outer layers protect the central part of the tooth, the pulp, which contains blood vessels and nerves.
Teeth are held in place by roots which extend into the jaw bones and are protected by the gums. (2)
Plaque is a substance which builds up on the outside of the teeth. This can be felt as a fuzzy coating on the teeth and is made up of bacteria, mucus and other particles. If it is not removed by brushing and flossing it can harden and form tartar. (3)
When bacteria in plaque comes into contact with sugars and starches from substances we eat and drink, acid is formed. The acid then attacks the minerals in the enamel, causing it to weaken.
When we drink and eat sugary and starchy items frequently, acid attacks increase and the enamel is weakened further. Eventually, over time, it is destroyed and a cavity, or hole in the tooth, is the result. (4)
Left untreated, this cavity allows bacteria to infect the dentin below the enamel and eventually the pulp. When this happens infection can enter the bones and gums causing abscesses. The culmination could be loss of the tooth. (5)
While not as prevalent as it was, tooth decay still affects many people of all ages. The introduction of fluoridation in water has helped, along with a better understanding of oral hygiene. (6)
The symptoms associated with this condition include:
Blemishes on the Teeth
Brown, grey, white or black spots visible on the white enamel of the tooth are a sign of the start of tooth decay. (7)
Sensitivity
Often the teeth will be sensitive to drinks which are either cold, hot or sweet. Drinking hot coffee laced with sugar, or eating ice cream, will trigger this symptom. (8)
Pain
When tooth decay progresses to the dentin layer the teeth can become more sensitive and painful. The pain could be constant and enough to keep you awake at night. It could also be short lived and only noticed when you bite down on something or chew.
The pain could be localized in one area of the mouth or might extend to the jaw, cheeks and ears. It can also be described as a throbbing pain. (9)
There are times when it may be felt unexpectedly with no apparent trigger. (10)
Odor
Poor dental hygiene, and the resultant growth of plaque, is one of the major contributors to bad breath. There are over 500 species of bacteria in the mouth, the majority of which produce nasty smelling compounds. (11)
When we don’t clean teeth properly or floss, plaque can build up on the teeth and gums. These bacteria contribute to tooth decay which in turn leads to bad breath. (12)
Bad Taste
Again, poor dental hygiene and the resultant build up of bacteria can leave a bad taste in the mouth. (13)
Stages
Tooth decay is a progressive condition unless treated. There are four stages from onset. (14)
Stage One
The initial stage is the appearance of white, grey, brown or black spots of discoloration on the tooth. These spots are the result of the start of breakdown of the enamel (demineralization) from the acid produced by bacteria.
At this early stage the damage can be reversed with the use of fluoride treatments or dental sealants. The fluoride protects the teeth and allows the enamel to remineralize.
Flossing and cleaning the teeth regularly with fluoride toothpastes will also help. (15)
Stage Two
This stage sees the tooth enamel begin to break down and bacteria enters the tooth’s surface. Enamel is the most mineralized material in the body and is very strong and robust. It can however not withstand the constant onslaught from acid.
Once a break appears in the enamel it cannot remineralize. Tooth sensitivity is likely to manifest at this stage. (16)
Stage Three
As decay progresses untreated, it damages the enamel and eventually reaches the dentin. This substance is softer than enamel. While fed by the pulp in the center of the tooth, once infected it is not able to regenerate.
Dentin is more porous than enamel and bacteria can spread quickly. Sensitivity and pain will be more pronounced when tooth decay reaches this level. (17)
Stage Four
At the centre of the tooth is the pulp. This substance is made up of living tissue (blood vessels and nerves) and cells (odontoblasts) which produce and maintain the dentin. When infection from tooth decay spreads to the pulp pus can form which kills the blood vessels and nerves in the tooth.
When tooth decay reaches this stage, pain is likely to be constant and throbbing. It also leaves the base of the tooth open to the formation of abscesses.
A dental abscess is a collection of pus due to infection at the base of the tooth or in the gum. This infection, untreated, can spread to the jaw bone or other parts of the body. (18, 19)
Treatment
When tooth decay is detected in its earliest stage discolored spots appear on the teeth. Brushing regularly with fluoride toothpaste or fluoride treatment from a dentist might help reverse the damage caused.
Once a hole appears in the tooth, called a cavity, it will need to be filled by a dentist. This involves drilling the enamel to remove decay, and then filling the cavity. There are options available for the material used to fill the cavity which your dentist will consider and discuss with you.
They include: composite resins, a mixture of quartz filler and glass which are a similar color to the tooth; dental amalgam, made from a metals including silver, tin, mercury and copper; and gold or a composite of gold, copper and other metals. (20)
When damage is severe a full or partial crown might be needed. Crowns help strengthen a tooth which has a large filling and therefore not enough of the tooth remaining to hold the filling. They are also used to hold a bridge in place if a tooth has to be removed. (21)
When the pulp and nerves are infected a root canal treatment will usually be done. This removes the infected root and pulp which is then filled and the tooth is protected with a crown. (22)
There are occasions when the only option will be to extract the tooth which is decayed. If this happens it can be replaced with a bridge, denture or implant. (23)
FAQ
What is tooth decay? Tooth decay (cavities or dental caries) happens when acid formed by bacteria in plaque on the teeth damages the enamel. Sweet foods and drinks and poor dental hygiene contribute to this condition.
What are the signs of tooth decay? Discolored spots which may be white, grey, brown or black in color might be seen in the teeth. Pain or discomfort as well as sensitivity to heat and cold are further signs of this condition.
How do you develop tooth decay? Tooth decay is caused by acid formed by bacteria on the teeth. The bacteria, called plaque, can build up if good oral hygiene is not maintained. When this happens the enamel in teeth is compromised and breaks, allowing infection to progress through the layers of the tooth.
How are you diagnosed for tooth decay? A dentist will examine your teeth and be able to see tooth decay. They may also take dental x rays to establish the extent of the damage.
What is the best treatment for tooth decay? The extent of the decay will determine the treatment needed. Early decay can be treated with good oral hygiene, using fluoride toothpaste or having a fluoride treatment. Once it progresses, fillings, crowns, root canal treatment or tooth extraction might be necessary. Your dentist will discuss and decide the best course of treatment for you.
What are the long term complications of tooth decay? The long term complication of tooth decay is the loss of teeth.
Is tooth decay considered a disability? Tooth decay can be managed and treated and is not considered a disability.
Is there a cure for tooth decay? When caught early, tooth decay can be reversed. However if it progresses there are treatment options available to remove the infection and restore the teeth. These include using fillings, crowns, bridges, dentures or implants.
Is tooth decay life threatening? While tooth decay is not considered life threatening, when left untreated an abscess can form. This pus filled sac can cause further infections which could be life threatening. (24)
Summary
Tooth decay (cavities or dental caries) happens when acid formed by bacteria in plaque on the teeth damages the enamel. This preventable condition is caused by poor dental hygiene, or consuming many sweet foods and drinks.
The good news is that tooth decay can be successfully treated. Brushing your teeth daily and using dental floss, as well as avoiding sugary food and drinks, can help prevent this condition.