Hi! I have porcelain fused to metal crowns on my front teeth and they are so opaque. It bothers me a lot, I dont know if the lab who made it is not good or maybe PFM's are not just aesthetically ok. Im planning to change it, I'm confused between all porcelain crows and zirconia crowns. Im considering aesthetics and durability. Which one is better? Thanks. Hope to hear from you.