Dennis Wayne Cernicky;54;of The South Mountain Restoration Center;South Mountain;Pa.;formerly of Long Branch;died Tuesday;Nov.22;1994;at the Center after a lengthy illness.  Mr.Cernicky was born May 28;1940;in Belle Vernon;a son of the late David Cernicky and Helen Ann Cowan Cernicky;who survives.  He had been a patient at The South Mountain Restoration Center for the past 12 years and was a Catholic by faith.  Surviving are two sons;Dennis and Derrik Cernicky;both of Long Branch;a daughter;Mrs.Michael (Denise) Green of Fredericktown;a granddaughter;Kaitlin Marie Green;and a brother and sister-in-law;William and Linda Cernicky of Belle Vernon.  A brother;David Cernicky;is deceased.  Burial;at the convenience of the family;will be in Belle Vernon Cemetery.  The Leonard J.Parzynski Funeral Home;626 Broad Ave.;Belle Vernon;is handling arrangements.