Loss of hard tooth tissue

Although teeth are made from the hardest substances in the body, loss of hard tooth tissue still occurs in the course of life, primarily due to mechanical and/or chemical action. Nevertheless, teeth are a very durable tissue and, therefore, well suited to study the evolution of dental diseases such as caries. On the one hand, teeth are easily accessible in skeletal skulls for a paleontological examination; on the other hand, they can be visualized in mummies by means of imaging diagnostic techniques (conventional x-rays or CT).

Today, caries represent one of the widest spread infectious diseases worldwide. Bacteria in dental plaque process carbohydrate in food left on the teeth and change it to acids that attack the hard tooth structure. In prehistoric times, introduction of agriculture and the higher starch intake which resulted from this, led to a strong increase in caries. Due to hard food and the mineral particles it contained, there was an abrasion of the chewing surface. A similar loss of hard tooth tissue or abrasion is very seldom nowadays.

In the course of the history of Ancient Egypt, the frequency of caries varied particularly within the upper classes. This can be attributed to an increased consumption of sugary foods (fructose from dates, honey, sweetened beer, liquor). In Europe, import of sugar (saccharose) from overseas starting from the 17th century, but more particularly local production of sugar-beet from the 19^th century on, caused a dramatic increase in caries. Thanks to fluoric treatments and improved mouth hygiene, caries rates have dropped again in the recent past. Due to the consumption of (sour) soft drinks and fruit juices, there is, however, a new emergence of superficial loss of hard tooth substance as a result of chemical action (so called acid erosion).

Mummies allow researchers to study dental pathologies and their evolution over time.

Loss of hard tooth tissue is dependent on dietary customs, available resources, social context and the state of scientific knowledge. Loss of hard tooth substance, therefore, varies according to the historical context of each individual.