Dr. Eder has developed an innovative way - the JEDER System - of carrying out a crestal sinus lift that substantially reduces the risk of perforating the subantral membrane. This minimal- invasive way uses 2 newly developed and successfully patented instruments, the "Druckkammerknochenfräse" DKK and the "Sinusvibrationspumpe" SVP. Following JEDER Syst. the mucous membrane of the mouth is opened from the toothless part of the maxillary crest up to the bone and the bone is scraped by a cylindrical cutter in the shape of a tunnel up to slightly underneath the maxillary sinus membrane.