I believe it's just a temp while waiting for the permanent fixed goody??
I did displays a while back for Direct Crown people. Dr M. Worthington came up with the product. It's a acrylic temp crown for use while waiting for the permanent. They marketed "shells" of various teeth. Acrylic was mixed chair side to attach to the tooth.
I still have the VPS molds I made for these guys. We made 1000s of display and trial models for these guys. They used them at variuos meetings the exhibited at. Little blue stone models. Opposing tooth on each side of a preped molar. Far as I know now, they sold the company, at least it changed hands a little. Last time I saw them they were available from Patterson.
Exactly...no dentist needed if some member of the public gets hold of a dental supply catalog and feels like "doing" it to themselves.
Direct Crown had was to have something in office and inexpensive (why not gold?),for a nice looking temp. I think a lot of people didn't come back for the next step of taking a impression for the porcelain crown. These crowns were quite durable.