"God's Tooth" was the name given to a unique energy-weapon technology used by the Bactricans. This weaponry appeared to disrupt matter at a sub-quark level, and according to Federation scientists, seemed to violate three basic laws of physics. The Federation was able to obtain working weapons during negotiations with the Bactricans in the 2350s decade. (DS9 - The Lives of Dax short story: "The Music Between the Notes")