Hmm...I guess it does. But composite is essentially plastic, right? From what I've learned it was always that amalgams hold up longer than composite but that composites are still preferred over amalgam for esthetics and lack if mercury. Cerec on the other hand is a pressed porcelain so it's stronger than the other two (and supposedly stronger than the original tooth structure), making it the longest lasting restoration. To be fair, I'm taking most of this from "hear say" (and my boss) rather than having researched this myself...so it could be biased information. Lol