One of the great dilemmas facing dentists is to create esthetic smiles for patients with severe wear, or destructive habits like habitual clenching and grinding (Bruxism).
severe wear |
Historically, the material of choice for patients who have these conditions has been the use of cast metal. The metal used was usually gold alloy, semiprecious, or non precious alloy in crowns and bridges. These metals gave restorations great strength and wear resistance. Unfortunately, metal has horrible esthetics.
metal bridge |
We still measure the longevity of all other restorative materials against metal alloy. A gold crown can function more than 50 years in the mouth.
In the early to mid 20th century, acrylic and porcelain were used to hide the metal and improve the esthetics of dental crowns and bridges. The problem with these esthetic restorations is the weaker porcelain can fracture off revealing the metal below.
porcelain fractured off porcelain/metal bridge |
Since then not much has changed in the fabrication of restorations until the use of Dilithium Silicate marketed as Eris™ and Zirconium marketed as Lava™, and Procera® and others. These materials utilize the Dilithium Silicate or Zirconium as a base layer (core) and overlay with porcelain. Dilithium Silicate is 3 times as strong as porcelain, while Zirconium is 10 times as strong as porcelain. These were the first strong "Metal Free" restorations that were used for crowns and bridges. Since their introduction, fracturing of porcelain is still reported in bruxers as the porcelain is still weak, so we kept looking for stronger materials with good esthetics.
porcelain fracture off porcelain/zirconium bridge |
Through experimentation, newer shades of Dilithium Silicate and Zirconium have been developed which have acceptable esthetics. These materials are E-Max™ and Bruxzir™. Both of these materials can be milled out of a solid block of material. E-Max™can be used with the CEREC™ in office milling system,which can be placed in a single visit for single crowns and onlays. Bruxzir™ must be made in a lab and will require 2 visits. Bruxzir™ has enough strength to be used in a full arch bridge.
We have been placing E-Max™ crowns in one visit for over 2 years with no breakage.
E-Max™ before |
E-Max™ after |
We have been using the Lava™ system for several years for crowns and bridges and now will be able to offer the Bruxzir™ system as well for our more severe cases.
Bruxzir™ bridge before |
Bruxzir™ bridge after |
If you have any questions you can contact us at:
phone 815 458 2202
or Email us at info@drneal.com
You comments are welcome
Sincerely,