In case tmj disc can't be functional any more and needs to be removed ,with what in can be replaced?

LAST RESORT ONLY!!!: TMJ surgery should be the LAST RESORT ONLY! I find it highly unlikely at your age you have reached that point already. Please first see if not one, two or three dentists who have extensive training and experience treating patients with TMD\TMJoint Dysfunction. Personally, I would travel to another country for a consultation before I would have TMJ surgery. See http://www.tmj.org/site/content/tmj-implants

Dr Munshower and another doctor agreed

Go conservative: While surgery was the only recommended treatment in the past, studies have shown that many patients are able to function without pain even when the disc is permanently displaced after the conservative treatment. See an orofacial pain practitioner for diagnosis and management. .

Depends: Many times it does not have to be replaced. Similar ot know when parts of disc taken out - nothing used to replace. Some replacements are fascia or fat. Your surgeon will use what works best in his hands.