Perio means around, and dontal refers to teeth. Periodontal diseases are infections of the structures around the teeth, which include the gums, periodontal ligament and alveolar bone. In the earliest stage of periodontal disease â gingivitis â the infection affects the gums. In more severe forms of the disease, all of the tissues are involved. For many years scientists have been trying to figure out what causes periodontal disease. It is now well accepted that various types of bacteria in dental plaque are the major villains. Researchers also are learning more about how an infection in your gums can affect your overall health.
Elephants are large mammals of the family Elephantidae and the order Proboscidea. Three species are recognised, the African bush elephant (Loxodonta africana), the African forest elephant (L. cyclotis), and the Asian elephant (Elephas maximus). Elephants are scattered throughout sub-Saharan Africa, South Asia, and Southeast Asia. Elephantidae is the only surviving family of the order Proboscidea; other, now extinct, members of the order include deinotheres, gomphotheres, mammoths, and mastodons.
The national and international trade in ivory of threatened species such as African and Asian elephants is illegal. The word ivory ultimately derives from the ancient Egyptian ab, Ã¢b (abu), Ã¢bu elephant Through the-latin ebor. or eburt has been valued since ancient times for making a range of items, from ivory carvings to false teeth, fans, and dominoes. Elephant ivory is the most important source, but ivory from mammoth, walrus, hippopotamus, sperm whale, killer whale, narwhal and wart hog are used as well.