Why are my teeth sensitive?

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Do hot, cold, sweet or acidic foods and drinks, brushing or sometimes even just breathing in air make your teeth feel painful or uncomfortable?  Then you have sensitive teeth.  Tooth sensitivity is very common, it is estimated that over half the population experiences some degree of tooth sensitivity.

Generally, sensitive teeth occur when the dentine (the soft inner layer of your tooth located underneath the hard enamel ‘shell’) becomes exposed due to the loss of its enamel protection allowing hot, cold or sweet foods to stimulate the nerve centre of the tooth causing pain and sensitivity.
However, there are many reasons why this may occur. It is very important to tell your dentist or hygienist if you are experiencing tooth sensitivity so that he or she can examine your mouth and determine the cause of your tooth sensitivity. Dental proplems develop over time, it’s important to catch them as early as possible.
Tooth sensitivity may be a generalised problem or can often be a symptom of more complex dental issues such as decay, gum disease or infections in the pulp or ‘nerve’ tissue inside your tooth

Generalised Sensitivity

Generalised tooth sensitivity is usually caused by exposed dentine on worn or eroded teeth, or root surfaces areas which have been exposed by gum recession.  Gum recession is extremely common and can be caused by gum disease or infection, incorrect brushing technique, clenching and grinding, or using abrasive whitening toothpastes. It may even indicate an underlying general health problem such as acid reflux.
Gum Disease – Bacterial infection of the supporting tissues of your teeth (gums, bone, ligament and root) which causes the gum to pull away from your teeth and expose the underlying sensitive dentine and root of the tooth.
Incorrect Brushing Technique – Repetitive damage over time to the gum and teeth from “scrubbing” your teeth or not using a soft bristled toothbrush. An incorrect brushing technique can cause the gums to recede, strip away the enamel near the gums and expose the sensitive dentine layer.
Teeth Grinding – Wear of the teeth resulting in the loss of enamel and exposing the dentine underneath, both on the biting surfaces of the teeth and near the gums. However, the damaging results of teeth grinding are not just limited to sensitivity.
Acidic drinks and foods – Frequent consumption of high acid containing foods and drinks such as citrus fruits, carbonated drinks etc can slowly wash away the enamel exposing the sensitive dentine layer.
Acid reflux – Stomach acid entering the mouth which washes away the enamel exposing the sensitive dentine layer underneath.
So what makes dentine and exposed root surfaces sensitive exactly?  Dentine contains thousands of tiny channels which are only visible with a microscope.  These channels run from the outer surface of your tooth, through the dentine to the pulp or ‘nerve’ tissue located in the centre of your tooth.  These channels contain fluid, which after eating, drinking, brushing or even breathing in air, the fluid in these tiny channels moves and irritates the nerve tissue inside your tooth resulting in pain.
You can greatly reduce your chances of experiencing tooth sensitivity by maintaining good brushing and flossing habits and a healthy mouth free from decay, erosion and gum disease.  Brushing and flossing daily as recommended by your dentist or hygienist with a low abrasive toothpaste is a great place to start.  Plaque (soft, sticky, bacteria infested film that grows on our teeth each day) produces acid which can make your teeth sensitive but also result in dental infections such as decay and gum disease if not removed daily.  A diet that is not high in acidic foods and drinks will also help to prevent erosion (acid dissolving tooth structure) and reduce tooth sensitivity.
To treat tooth sensitivity your dentist or hygienist may recommend a special toothpaste for you to use when brushing.  These toothpastes contain special ingredients which help to block up the dentine channels to stop you from experiencing pain or calm the nerve inside of your tooth.  Fluoride and mineral treatments may also be applied to your teeth during dental appointments to help treat sensitive areas which do not respond to using these special toothpastes.
Tooth sensitivity doesn’t have to spoil your appetite! Remember to discuss any sensitive areas you may have with your dentist or hygienist so that they can determine the cause of your discomfort and ensure that your mouth is healthy and free from more serious problems.

Single Tooth Sensitivity

Sensitivity that occurs with a single tooth tends to be associated with more serious conditions that have affected that one tooth. It may start as mild sensitivity or feel similar to the sensitivity described above, but usually increases in intensity over time to pain as the condition worsens.
Cavity/Decay – Bacterial infection burrows progressively deeper inside the tooth causing inflammation of the nerve centre (or “pulp”) of the tooth.
Chipped/Broken Tooth – Fluid moving in the cracks can stimulate the nerve (or “pulp”) especially when chewing, or eating or drinking hot or cold foods and drinks. The cracks can also act like a gateway for bacteria to burrow deeper into the tooth and cause infection of the nerve of the tooth. If the tooth breaks large amounts of dentine or even the nerve of the tooth can become exposed causing severe pain.
“Pulpitis”  – This is where the nerve (or “pulp”) of the tooth becomes inflamed and/or infected due to active deep decay or cracks, or a previous history of decay, trauma, or cracks in the tooth.
These types of sensitivity will not improve with sensitive toothpastes or resolve over time. Immediate treatment is required by your dentist to not only resolve the sensitivity or pain, but to reduce the risk of complications or more extensive treatment.