Tooth never loose now loose after gum graft. why?

Loose tooth: There is no way to know this without knowing your dental history, having a clinical exam, and seeing pre- and post-op x-rays. Contact your dentist and/or the dentist that placed the graft.

Preexisting disease?: If you had preexisting periodontal disease in that location, the cleaning and preparing of the graft site could have caused a temporary loosening of the tissue, or you could have had a build up of calculus that had to be removed in order to do the graft, and that build up could have been keeping the tooth stable. I would ask your surgeon. :)

None: I can not think of anything about the procedure the would loosen the tooth. IF that was the only procedures performed. That said, I have two possibilities, one you are simply more aware of the tooth. two, the discomfort has caused you to grind on the tooth and loosen it. As the pain subsides the tooth will return to normal.

Traumatic bite: One of the reason why you needed a gum graft,because you had recession of gums on that tooth. This recession may have happened due to a traumatic bite on that tooth from opposing tooth,leading to loss of bone,that lead to gum recession.after a surgery, there can be an inflammation & pain.Traumatic bite can exaggerate the condition.You may need occlusal adjustment to balance the bite.infection ?

Loose tooth: Usually means supporting bone loss which is often mirrored by tissue loss, thus the need for bone graft. Return to the General Dentist, Periodontist, or Oral Surgeon that did the graft for reevaluation.