One of the early uses of materials in humans was in dentistry. Neanderthals and modern humans used toothpicks made of wood or bones. Even before humans started farming 10,000-15,000 years ago, more sophisticated forms of tooth-digging methods using sharp objects made of Flint were explored.
These methods involved scratching or levering of the tooth, and were neither superficial like using a toothpick to remove food nor deep-drilling to remove the decaying tooth.
Oral cavities bear a resemblance to holes created in wood by worms. Thus, tooth worms were thought to be the cause of tooth decay from ancient times in various cultures (Indian, Sumerian, Egyptian, Japanese, and Chinese) until the early part of the millennium (the 1300s).
Of course, now we know, oral bacteria, such as Streptococcus mutans are one of the causes. These bacterias convert carbohydrates into enamel-destroying acids. Scientists think that increase in the use of a carbohydrate-rich diet that started before the advent of farming and grew as agriculture became more common as a cause for the rise in tooth decay.
During the Indus valley civilization (7,500-9,000 years ago), Flint-based drill heads were used in drilling deep (up to 3 millimeters wide, and 3.5 millimeters deep) into rotten dental tissues to perhaps relieve pain or treat infections. Bead artisans were thought to be suppliers of these drill bits. The scientists who conducted this study speculated that given the extent of the drilling, some filling must have been placed in the cavity.
Beeswax, embedded in a deep tooth cavity of 6,500-year-old jawbone recovered near Italy, is one of an oldest documented case of material used to fill tooth cavity. The beeswax was probably used as filler to mitigate pain and swelling.
Sidenote for students: When you read the above research articles that provided the evidence for the presence of materials in ancient human specimens, please pay particular attention to the analytical methods.
Similar analytical methods are used to study the surface properties of modern biomaterial implants as well as in implant retrieval and evaluation. More on this in later blogs.