Cosmetic Dentistry Update on Crowns (Caps), Onlays and Inlays
Why is this important? If you have damaged teeth or cosmetic issues and would like attractive, strong teeth then read on. Dentistry has had some major advancements in a very short period of time especially in the materials we use to restore teeth. Knowing about the various materials will enable you to make more informed choices if you need any of these services.
Crowns, or caps as they are commonly called, cover the whole tooth. These are needed when a tooth has considerable damage or cosmetic problems. Crowns can be made of all gold, ceramic over metal or all ceramic. Many years ago researchers developed a process where ceramic could be added over metal for a more esthetic look than all gold. The traditional ceramic over metal crown can be very beautiful. Its drawbacks are that it can leave a dark area at its edges if not planned well and the ceramic over the metal is weak and prone to fracture. There is also an all ceramic crown that has been around for many years but it is very weak and subject to fracture. To summarize, gold is the most durable and least esthetic, newer ceramics are the next most durable and can be very esthetic, and the older all ceramics are the least durable but very esthetic.
Onlays are partial coverage restorations that allow the dentist to restore only the damaged part of the tooth leaving the healthy part of the tooth undisturbed. Onlays are great options for back (posterior) teeth that are damaged but not bad enough to need a crown. These are partial coverage restorations that can be made in gold or ceramic. When restoring teeth it is important to preserve as much heathy tooth structure as possible because most teeth that are restored will need to be restored again sometime in the future. It is possible to make these restorations look so much like natural teeth that it is hard to tell that the tooth has been restored.
Inlays are meant for medium sized restorations where most of the tooth is intact. Today, inlays are less commonly needed due to the advancements in the strength of both bonding adhesives and tooth colored filling materials, so I will not discuss these in any depth at this time. Historically, crowns, onlays and inlays were made from all gold for strength. It is rare, but even today there are a few situations where maximum strength, all gold, is most appropriate. The newest generations of all ceramic materials are much stronger than previous all ceramic and ceramic over metal materials. There are two main types with one being extremely strong but less esthetic (zirconia) and the other being very strong and very esthetic (lithium disilicate). These new alternatives give the dentist and patient more choices when deciding on the right combination of strength and esthetics.
If your tooth or teeth need to be restored due to damage or esthetic problems you and your dentist now have many options to consider to attain the right combination of strength and esthetics.
Dr. Robert A. Gallegos is a Fellow in the Academy of General Dentistry, visiting faculty of Spear Education, a member the American Academy of Dental Sleep Medicine, the American Academy of Cosmetic Dentistry, and the American Dental Association. Dr. Gallegos practices dentistry in Middleburg, VA. www.MiddleburgSmiles.com.