Randy Robitaille and Jason Blake also scored for the Islanders, who had dropped nine of 11.
Randy Jones and Simon Gagne scored goals, and Peter Forsberg had his 600th assist for the Flyers, who have the fewest home wins (three) in the NHL. Their last victory at home was 3-2 over Columbus on Nov. 24.
Sillinger, a former Flyer, scored on a power play at 3:27 of the third to break a 2-2 tie. He converted a rebound of a shot by Miroslav Satan. Hilbert scored from the left circle at 4:45.
Goaltender Rick DiPietro had 29 saves for the Islanders. Philadelphia's Antero Niittymaki stopped 32 shots but suffered his 14th straight defeat (0-13-1).