   We commonly see tooth wear; see the yellow lines which are where the dentine, the inside layer of the tooth is exposed. The teeth are thinning out and the tooth enamel is Chipping away. Some resin has been used to try to rebuild one of the teeth and it is failing and chipping away also. The teeth also have radiating hair line fractures. These teeth were rebuilt with three quarter porcelain crowns 7 years ago, which are extremely strong and have stood the test of time.