Immediate implant and delayed infection?

I did this immediate implant 3 months back. Labial cortex was damaged coronally, but apically was good. So we placed an immediate implant after atraumatic extraction and gave a temporary crown. 2 months later the patient presented with an abscess with a sinus. Radiograph was good at that time with no unexpected bone loss. So we prescribed her antibiotics and it resolved within a week. Now again after 1 month she came with a sinus complication. Attaching present radiographic images also. This time we removed the temporary crown. The gingiva was slightly inflamed. We put a healing abutment this time after thorough irrigation. The temporary crown, on careful observation was slightly rough at one area. We are thinking that this must be the reason for the microbial plaque accumulation and subsequent pericoronitis. Please provide your expert opinion and comments for this. We are still learning and appreciate your help. How should we proceed now?