The conical shape is the basis of the system of conometry and was envisaged by professor Karlheinz Körber at the end of the 1960‘s to retain removable prosthetics. He definitely had the theoretical idea because in the past the fit of telescopic crowns was often too tight due to expansion troubles with investments and casts. This made the handling of a telescopic denture difficult for the patient. At worst, the periodontal structures were damaged and the support teeth sometimes were lost through an unintentional extraction.