Tooth decay

Bacteria constantly multiply in food particles in the mouth, particularly on the teeth and trapped between the teeth. When bacteria build up, they form a sticky, colourless substance called plaque (pronounced 'plaak'), which is the main cause of tooth decay and gum disease. Bacteria produce acids that destroy tooth enamel, enabling the bacteria to penetrate into the internal structure of the tooth (look back at Figure 6.2) and cause decay. When plaque is not removed by brushing, it hardens into tartar (or calculus), which is very difficult to remove. The growing layer of tartar pushes the gums away from the tooth and in time it may become loose and fall out.

Certain foods contribute to plaque formation. A diet high in sugar and starch will eventually result in tooth decay. Today, in most parts of Ethiopia, sugar appears to play a key role in the increasing rates of tooth decay. Sugar cane, soft drinks, biscuits, candy, other sweets and refined sugars are readily available in every corner of the country, and the use of sugar as a sweetener in tea and coffee is now universal in both urban and rural Ethiopia. This is having a negative impact on the dental health of the population.

Using tobacco also increases the risk of developing gum disease. Smoking and chewing tobacco and khat contribute to plaque and tartar build up, as well as causing oral cancer (see Section 6.2.4).