Clinical Use of Periotomes :  By severing the PDL prior to extraction, the surrounding tissue is subjected to less trauma, and in many cases, allows for immediate placement of an implant.  To use a periotome, place the blade of the instrument down into the sulcus, severing the PDL.  Lift the blade out of the sulcus, and repeat the process, moving circumferentially around the tooth.  This will sever the PDL except for where it connects at the most apical part of the tooth.  Afterwards, use a periosteal elevator and extraction forceps in the usual manner.