I had a patient in a provisional on tooth #7, and he called to tell me he ate the crown. When he came in, I checked his occlusal marks in MIP, and there was a nice coupling with the opposing tooth. He was not hitting the tooth at all in protrusive, in right and left, and in crossover. He had not used floss and had not chewed on something sticky that would pull the provisional off. So, I put articulating paper between his teeth and used my iPhone to video him as he chewed like he was chewing food. What I discovered in the video is that he had a functional interference. He had broad strokes on the provisional whenever he was in his chew stroke.
I sent the video to the lab with the hope that the new information could be used to make a crown that would protect the tooth from breaking or becoming loose. This patient was adamant about not wanting orthodontics. I was able to show him why equilibrating his opposing tooth would be beneficial and he accepted equilibration.
Having run into this problem once, I am now checking for functional interferences with more patients by having them do “the chew test.”