Are you sensitive? That is, suffering with dentine hypersensi-tivity (DH). It is an intense pain felt when the dentine of the teeth are exposed to hot or cold foods or drinks.

Hypersensitivity means that there is a painful response to stimuli which is not normally associated with pain. Beside hot or cold foods or drinks, stimuli that can trigger the acute pain associated with dentine hypersensitivity are:

1. Sweet or sour (acidic) foods

2. Overly aggressive brushing causing tooth abrasion

3. Receding gums

4. Plaque and bacteria

5. Gingivitis

6. Periodontal disease

7. Cosmetic whitening or bleaching

8. Teeth clenching or grinding

9. Dry mouth

10. Cracked or chipped teeth

11. Pressure

Dentine hypersensitivity is one of the most common painful conditions affecting the mouth. This pain is very sharp and short, arising from exposed dentine as a result of receding gum and subsequent loss of cementum on the root surfaces to the point where the dentrial tubules becomes opened. Once the dentrial tubules are disturbed, a rapid flow of liquids trigger nerves along the pulpal canal of the dentine causing pain.

One in five adults suffer from sensitive teeth. It can start as early as in your 20s and becomes more intense as you get older. The most common affected teeth are the upper canine and premolars on the outer surface to the neck of the teeth, where you have enamel loss.

Eating disorders

Dentine hypersensitivity is caused by erosive and abrasive factors. The erosive factors are intrinsic and extrinsic acids. Intrinsic disorders, for example, vomiting, regurgitation and eating disorders like anorexia and bulimia nervosa contribute to DH.

High intake or abuse of modern 'lifestyle drinks' (which often contain high amounts of titratable acid) or diets high in fruit drinks, vegetables or other acidic beverages and medicaments can contribute to erosive effect of removing the tooth structure thereby opening the dentine tubules.

For many years, clinicians have focused on physical factors like toothbrush abrasion and abrasive dentrices as contributing factors to DH. Excessive and improper brushing using toothbrushes which are too firm as well as abrasive toothpaste can contribute to DH. This erosive and abrasive effect is responsible for cervical enamel loss resulting in dentine exposure and a ready opening of dential tubules.

Treatment

In mild cases of DH, assisting the patient with educational advice, including proper brushing with a soft toothbrush, flossing and excluding all predisposing factors should be the primary aim to prevent recurrence. Also, the use of desensitising dentrifics, for example Sensodyne toothpaste containing either strontium salts (chloride or acetate) or potassium salts (chloride or nitrate) is very valuable in this stage.

In cases of moderate severity, the dentist will apply a varnish or lacquer containing high concentrate of fluoride and advise the patient to do follow-up care with home use of desensitising toothpaste as in mild cases.

In severe hypersensitivity cases, the treatment is semi-invasive or invasive. Semi-invasive treatment include use of filling, sealants and resin bonding agent. In invasive cases, the use of crowns, periodontal surgery - grafting, root canal therapy and in the worse case scenario, an extraction.

Reader's questions

Dear Dr Jones,

I read your article on the subject matter oral hygiene dated February 27. You gave a list of things that were myths and then things to be practised. My question to you is, what if someone has sinus troubles? Would this cause that person to have 'bad breath' as well? Seeing that the sinuses tend to drain, would this affect the person's mouth odour and what can be done in such cases?

I don't know if you are a dentist or a medical doctor, but what is your take on sinus rinses? Will they help with mouth odours as well? My mother is big on using hydrogen peroxide. Is this useful?

Thanks much.

Dear Reader,

Sinus troubles (sinusitis) is one of the general diseases that contribute to bad breath. Persons with sinusitis should go to the physician and, based on the severity, he/she will recommend a treatment plan which might be non-invasive or invasive. Once your sinusitis is cured, bad breath from this source will also go. The use of sinus rinses or mouth wash will only temporary relieve the problem of bad breath. Good luck.