I know this is an old question, but given that it came up in a search today, I thought I would clarify since others may find it in a search. Scottma is somewhat correct, but not entirely. I am 30 years old and have dentinogenesis imperfecta, type 3. What I will say below comes from personal experience and things I have learned from top dentists at the University of Maryland School of Dentistry and from geneticists at Johns Hopkins University.
There are three forms of dentinogenesis imperfecta (DI). Type 1 is associated with Osteogenesis Imperfecta (brittle bone disease). Types 2 and 3 are NOT associated with OI whatsoever. Type 3 is known as the Brandywine variant as it is limited exclusively to a people group in southern Maryland. DI Type 1 (associated with OI) affects primary teeth more than secondary. Types 2 and 3 affect both primary and secondary teeth equally. Type 3 is the most severe.
"The affected tooth may be managed by a full coverage crown." As far as referencing a single affected tooth, this doesn't sound like DI. Perhaps it is in reference to a very mild form of DI, but most people with DI have issues with ALL of their teeth. It is a genetic issue, and genes aren't selective about which teeth are affected. And crowns often don't help. Crowns are a conventional treatment advised by a traditional dentist. It's logical: Cap the teeth, and they won't wear. Unfortunately, I've read countless stories of people with DI who had caps put on, only to have those teeth decay faster than the others. That was my experience. I had four caps put on my back teeth with the dentist saying it would decrease the wear on my remaining teeth. Those four teeth decayed terribly.
The best advice: Full OVER-dentures. This means the dentures are molded to fit over the natural teeth until the jaw is mature enough to accept implants in adulthood. Some DI patients have enough jawbone to have a full fixed bridge. I don't, so I will be having an implant-supported denture as my next procedure. Dentures are LIFE CHANGING for those with DI. For a child, a full over-denture ends the teasing, the curious stares, and the ostracism. It protects the teeth while allowing good oral hygiene. That's the other key: Those with DI must keep good oral hygiene. With bad genetics, you can't prevent your teeth from falling apart, but it's important to keep your gum tissue as healthy as possible.
Best wishes to your friend and her child. DI can be a frustrating, heartbreaking, and expensive burden to bear. From personal experience, I can also say that it will build character if you find a way to hold your head up high through it all.
Dentinogenesis imperfecta is a hereditary disease frequently associated with osteogenesis imperfecta.The primary teeth are more severely affected than permanent dentition.The affected tooth is described as blue, brown, or amber opalecent discoloration.Teeth that are discolored are more prone to enamel wear and fracture. The affected tooth may be managed by full coverage crown.