How long should bleeding last after extraction while on Lovenox?

My father had 10 teeth extracted to get an upper dental plate. He is 82 with a number of health conditions. He is on Warfarin due to a mechanical heart valve. His primary doctor decided to bridge him with Lovenox for the surgery to prevent blood clots. He discontinued Warfarin 5 days before surgery. Three days before surgery he started 80mg of Lovenox by injection 2x per day including the morning of the surgery. He bled so much he stayed at the dentist's for 8 hours. He was sutchered twice by two different dentists. He skipped a dose of Lovenox that night and stopped bleeding at 2 in the morning, 13 hours after surgery. The next morning after his shot of Lovenox he started to bleed again. The primary doctor is insistent he needs this medication however he reduced to half, 40 mg 2x per day. He is also warning of increased risk for stroke. He has to take these shots until he stops bleeding and then bridge back to Warfarin. It is now a week later and he is still bleeding. It has reduced but generally increases 2 to 3 hours after the shot. He can barely eat or sleep and constantly has gauze in his mouth. The first 3 days he had giant blood clots that were falling out of his mouth. He is avoiding spitting. Finally there seems to be some healing as grey scab-like matter is forming on the clots, but again still bleeding. The dentist said he never had anyone take Lovenox the day of surgery and I fear that started this all. But again the doctor is insistent. Now I have the concern he is not getting the full dose of medication but also isn't stopping bleeding. I can't find any research that promotes the use of Lovenox during extractions. Usually Warfarin is just held. And when bridging to Lovenox is done, I read that Lovenox is held 24 hrs prior to surgery. At this point it's done and he can't bridge back to Warfarin until the bleeding stops. Is there anything that can be done to stop the bleeding? Any help would be greatly appreciated.