In the mid-23rd century, a Vulcan science vessel detonated a pulse wave torpedo inside a subspace rupture which they had encountered in the Hanoli system, in an attempt to seal the tear. Their plan backfired, however, and the entire Hanoli system was destroyed.
In 2369, upon encountering what they thought was another subspace rupture, the crew of Deep Space 9 attempted to improve upon the intentions of the Vulcans by detonating a pulse wave torpedo inside the rupture. It was hoped that their effort would be more successful, as better ways of controlling the flux density had been developed in the intervening years. The effort proved futile, however, and the rupture continued to expand. (DS9: "If Wishes Were Horses")