For esthetic purposes, I elected to have an old pfm crown replaced with a zirconium crown about six weeks ago. There are visible margins with this new crown. I want my investment to last as long as possible. With the margins already visible, I worry about the longevity of the crown (with natural gum recession) as well as esthetics. Why is this an acceptable form of practice now? It doesn’t pass for a natural looking tooth. My old crowns were placed beneath the gum line with no issues.