two 20 year old front crowns #8, #9 with posts and one cracked tooth #10. The old crowns looked terrible, pulled away from the gum and caused me to bite my lip when chewing. #10 had a hairline crack recently, greying and was sensitive. The dentist said he thought he could improve the work adding 3 crowns. After removing the 2 crowns and grinding down the good tooth he said fusing all 3 together would make them stronger.