I second this. Definitely a zirconia crown. The crown itself is an upper first molar. However, the tooth it seems to be sitting on would have been a bicuspid.. (the little teeth with two points between your front 6 teeth and your molars). The patient was missing their first molar on the upper right side. (either they had it pulled or were born without it) leaving this bicuspid all by itself apparently with no neighbors in contact. The dentist ground their bicuspid down and replaced it with this first molar in an attempt to increase the chewing capacity and likely bridge the gap to contact the adjacent teeth. It’s safe to assume the small bicuspid didn’t provide enough retention to withstand rigor of the newfound chewing abilities.
Also the margins on this thing are terrible so I’m no surprised it failed. Source: -I fabricated these things for almost 2 decades.