What are Composite fillings (white filling or resin fillings)?

Composite fillings are resins of tooth-colored plastic filled with glass (silicon dioxide).  Introduced in the 1960s, dental composites were confined to the front teeth because they were not strong enough to withstand the pressure and wear generated by the back teeth.  Since then, composites have been significantly improved and can be successfully placed in the back teeth as well. Composite fillings are not only used for restoring decay, but are also used for cosmetic improvements of the smile by changing the color of the teeth or reshaping disfigured teeth.  You can see examples of cosmetic work done with composite fillings here.

How are composite fillings placed?

First, all decay is removed and the tooth is further prepared with some roughening so that it can be solidly bonded to.  The next step usually involves placing some type of barrier to ensure the area can stay dry, does not get contaminated with saliva or blood, and that only the tooth we want to work on gets bonded to.

Once the tooth is ready, an etch is placed on the tooth to open pores that will allow a mechanical/chemical bond to form.  Next a desensitizing agent is placed on the tooth and dried.  This is followed by a primer and then a bonding agent that is cured with a special blue light.  Finally the composite will be placed in layers, using the specialized light to harden each layer.  When the process is finished, we will shape the composite to fit the bite.  We then polish the composite to prevent staining and early wear.