No, fortunately, this has nothing to do with dentistry. One of the world's strongest wood varieties is the South American Kebraucho with the alternative common name of Kwebrahoe, literally — quiebra-hacha, or "break the ax". In 1928, the Russian sculptor Stepan Erzya became the first to use this variety of wood in his practice. In order to efficiently process material of such high density, because of which it does not burn or sinks — Erzya used a specific drill made by a German firm according to his blueprints. For the past time the machine has not lost the functionality and currently resides in the collection of the sculptor Mikhail Ilyaev, to whom she was presented by the pupil of Erzya — Julia Kuhn.