Jul 28

Metal Free Fillings, Are We There Yet?

Material advances in both direct placed bonded fillings and laboratory fabricated ceramic fillings are changing faster than cell phones.

A little background on bonded fillings and their different types is required at this time. 

Bonded fillings are essentially a glass partical and plastic resin composite material.  Thinking about it as a plastic asphalt is a good way to picture it.  The glass or silicate particles gives the material it wear resistence and the plastic resin keeps it together.  Composite resin fillings can be placed on back teeth, but it does have its limitations. 

The term direct placed means just that.  Material is taken out of a syringe and placed in the tooth and cured (made hard) with a light to make it set up. 

Composite resin fillings on back or posterior teeth are harder to place than fillings on front teeth.

Extra care must be taken to ensure that the area is dry in order to have a good bond to the tooth. 

All composite resins shrink when cured or made hard with the light.  Stacking the material in small increments helps prevent the shrinkage from causing bonding failures. 

This technique is very important to prevent immediate problems post op such as sensitivity to biting.  It will also play a role in determining the longivity or serviceability of the filling. 

The limitations of a direct placed filling really is how much remaining tooth structure is left.  If the filling is too big, it will fail prematurely due to excessive wear from chewing.  For these larger fillings, a better alternative is a lab fabricated ceramic filling. 

This doctor uses a material called IPS e.max.  It something called a lithium disilicate and is a type of ceramic.  It is made by a milling process at a laboratory.   The final restoration or filling fits into the tooth like a little jigsaw puzzle piece.  These restorations are very strong and beautiful and life like in appearance.  They are ideal for where a direct placed composite filling would fail because of excessive wear.  There are also now zirconia ceramics which are so strong bridges can be built where teeth are missing.  The results of these bridges are impressive.  This doctor now has placed several bridges of all zirconia and they now have several years of service on them.  I personally am fabricating fewer porcelain fused to gold crowns than I did in the past.  One exception is crowns on implants.  The idea of cementing a ceramic crown on a metal post I believe may cause stress on the ceramic over time. 

So are we metal free yet?  I believe we are very, very close.  Dr. Dibling would be happy to discuss your options with you in a free consult at any time.