Why is my crown just now hurting? I got a new night guard about 8 months ago. Is this related?

I had a crown put on my left upper front tooth, probably back in 2004 (I was in my early 20s). I always wore my mouth guard when playing soccer and can count on one hand the nights I didn’t wear my night guard since I got the crown. My night guard was adjusted for this crown and all my others. June 2018 I got a new night guard from a new dentist. Every now and then since I got this night guard I have pain in my front tooth with the crown. Is this related?