Is it my teeth or sinuses causing my pain and congestion?

I recently had to have a tooth extracted due to an abscess. I was started on antibiotics. I wanted an implant and had it placed the same day I had the extraction. The X-RAY showed a huge pocket of pus and my roots of my molar were very close to my sinus, causing my recurrent sinus infections. I felt relief almost immediately. Now six months later after I recieved my crown, again, my sinus infections are back. Is it my teeth or my sinuses? Should I see an ENT?