Flap dehisence: What should be done?

I placed this 5×11.5mm implant in the lower second molar region. Patient is a chronic smoker. After a week, the patient presented with flap dehiscence. I re-sutured and again the same picture. Next time I completely raised the flap and passively approximated the edges and re-sutured. But the same picture after a week. Now I decided to let it be. Patient was asymptomatic until last time but now he complaints of intermittent pain in the implant site. Also when I raised flap to re-suture I noticed 3-4 exposed threads on buccal side. I flushed this area out. Now what should be done? There seems to be no infection. The problem is the exposed cover screw.