White Filling or Silver Filling?

White filling or Silver filling? That is the Question.

Also, it is controversial question asked in dentistry today.  To date, there are no scientific studies that prove amalgam fillings are harmful to patients’ health.  However, there are no conclusive studies that prove its safety either.  So, although there is no absolute answer to this question as far as health is concerned, there are considerations that should be tailored to the individual’s needs, preferences, location, and size of the decay.   Before we explore the variations and evaluate the pros and cons of both types of restorations (fillings), there are some interesting facts to know.

To put to rest some fear regarding the bad rep that silver (amalgam) fillings have received over the last few years, did you know that less than 1% of the population has an actual allergy to amalgam fillings?  Although dental personnel are exposed to mercury more and have 4-5 times more mercury in their urine than the average person, they do not have a higher incidence of neurological (such as multiple sclerosis) or gastrointestinal diseases as has been suggested.  In fact, the amount of mercury released from chewing is extremely small (1-3 micrograms), and is less than what patients are exposed to everyday from air, water, fish, and other foods (5-6 micrograms per day).

Amalgam or “silver” fillings have been around for over 150 years and are made from a mixture of mercury, silver, zinc, and copper.  There are many advantages to an amalgam filling.  The tooth does not have to be isolated and kept completely dry for a successful filling to be placed.  It starts out as a soft material that is easy to use and manipulate during placement, packs into any size of cavitation (hole), and then hardens to become an enduring restoration that will last up to a third longer than a composite restoration.  The elemental composition of amalgam is bacteriostatic, which means it inhibits growth of new organisms around the filling-tooth margin, so new decay is likely to progress more slowly than with a composite filling.  It is also less expensive than tooth colored restorations and is covered by dental insurance companies.

Composite restorations are made from a mixture of glass or quartz and a resin medium, and they are tooth-colored.  Obviously, this makes them more acceptable esthetically.  This is especially important for front teeth fillings that will show upon smiling or speaking.   In preparing a tooth for a composite filling, the dentist does not need to remove as much tooth structure to place the filling as when preparing a tooth for an amalgam.  Although the silver filling is more durable and considered a stronger material, many practitioners argue that because the tooth is bonded to the filling material, it actually makes the tooth stronger once bonded, so there is less fracturing of cusps from a composite filling.  Another benefit of a composite is that there is less sensitivity from hot or cold because they do not conduct thermal changes as does a metal filling.  Patients can also eat right away after the placement of a composite filling it is light cured in a very short time.  An amalgam takes up to 8 hours to completely harden or cure.  One more added bonus is that in some cases, a composite filling can be placed without the need for local anesthesia or drilling, depending on the size and location of the filling.

In the past, amalgam fillings were used in the posterior teeth because chewing demands a stronger filling that will hold up to forces put upon those teeth.  Composite fillings were used for the front teeth where silver would be less attractive.  Today the choice is not so black and white.  Composite materials have improved and are strong enough to be used for posterior teeth.  However, they are very technique sensitive.  They need to be completely isolated and kept dry to be successful, and when that is not possible, a silver filling may be the best solution.  They are also more time consuming for the dentist to place (which also means longer time in the chair for the patient) because they must be placed and cured in layers.  Most dentists need extra training to learn the proper technique for placing posterior composites.  The extra time and education required for the dentist is the reason they cost more.  Additionally, insurance companies may not cover the cost of the composite filling, or they may only pay what an amalgam would cost (in posterior areas of the mouth) which leaves a balance to be paid for by the patient. 

Fillings are not new.  As early as 659 A.D., silver paste was used to restore a tooth in China.  In years past, fillings were made from stone chips, resin, cork, turpentine, gum, gold leaf, and even lead was used!    Fortunately, our choices, though somewhat controversial, are so much better.  When choosing between the two, discuss all options with your dentist and decide which is best for you. 


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