What is a composite resin (white filling)?

A composite filling is a quartz resin. 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. Composites are not only used for restoring decayed teeth, but are also used for cosmetic improvements of the smile by changing the color of the teeth or reshaping disfigured teeth.

How is a composite placed?

Following preparation, the dentist places the composite in layers, using a light specialized to harden each layer. When the process is finished, the dentist will shape the composite to fit the tooth. The dentist then polishes the composite to give it a surface that is hard to tell from enamel.

How long does it take to place a composite?

Because a composite is more difficult to place than silver fillings, it takes the dentist about 10-20 minutes longer to place. Placement time depends on the size and location of the cavity.

What is the cost?

Prices vary, but composites average about one-and-a-half to two times the price of a silver filling. Most dental insurance plans cover the cost of the composite up to the price of a silver filling, with the patient paying the difference. As composites continue to improve, insurance companies are more likely to cover the cost of composites.

What are the advantages of composites?

Esthetics was the main advantage when they were introduced. There is still no question that a tooth colored filling looks better than a silver filling which turns black overtime.

The main reason that Dr. Miller changed to tooth colored fillings even in the back of the mouth is that silver fillings require more healthy tooth structure to be removed than with composite fillings. Silver does not stick to teeth so when silver fillings were done, the decay was removed and then a trench was dug into the tooth to help lock it in place. Most of the time entirely healthy tooth structure was cut away to help hold the silver in place. Silver fillings are ALWAYS bigger inside the tooth. Tooth colored fillings adhere to teeth so Dr. Miller can use the drill like an eraser. Once the decay is erased; the tooth is ready to be filled.

Another drawback of silver is that it expands and contracts more than teeth. When teeth expand and contract thousands of times, your teeth are exposed to hot & cold, the filling and the tooth separate which leads to cracks in the teeth where the enamel is unsupported. Composite resins (tooth colored fillings) expand more similarly to teeth and are much less likely to cause cracks in tooth structure since they adhere to tooth structure anyway.

Silver fillings also contain mercury and other trace elements that can leech out as silver fillings break down. This problem is totally avoided with composite resins as they contain no mercury or heavy metals of any kind.

Composites bond to the tooth to support the remaining tooth structure. Composites are the first dental material that actually lets dentists give strength back to the tooth. Previous filling materials derived their strength from what was left of the tooth.

What are the disadvantages of composites?

The main disadvantage is cost. Even though composites have been used since the 60's, some insurance companies still treat them as "experimental" and will not cover them, even given the drawbacks of silver fillings.

Another drawback is they take longer to place. They are more technique sensitive and are placed in layers for strength, which takes longer. Composite resin must be placed in a dry field. In other words, your mouth has to be made dry for them to bond properly. Hello Cotton!

Composites also tend to wear more similarly to enamel which is an advantage and a disadvantage depending on the surface they oppose.

How long will a composite last?

Studies have shown that composites last 7-10 years, which is comparable to silver fillings. The ADA keeps statistics on silver fillings (Boy I'll bet you wish you had that job!). The ADA's statistics show silver fillings last an average of 7 years. The fact that silver fillings remain locked in place does not necessarily mean that they are not leaking. Think of that the next time you drink a soft drink!

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