Advantages: Dental amalgam is a mixture of silver-tin-copper alloy powder and liquid mercury. It is self hardening and forms a silver colored fill. They are durable and last for a very long time, sometimes as long as 20-30+ years! Because this type of filling is so long lasting, dentists infrequently need to perform repair and replacement work on them. This also means that they are relatively inexpensive compared to other types of fillings, and they are also more readily covered by insurance plans. Amalgam fillings can generally be completed in a single visit, and their self-sealing property allows for minimal-to-no shrinkage and resists leakage. This type of filling is also very resistant to further tooth decay, although it can be difficult to notice additional decay in its early stages.
Disadvantages: Many people find aesthetics to be the main disadvantage of amalgam fillings. Because they are gray and not tooth colored, they can be easy to see when a person opens their mouth. The filling can also darken as it corrodes and may stain teeth over time. Placement of the filling does require the removal of some healthy tooth material, and in the case of larger fillings the remaining tooth might weaken and fracture. Other disadvantages result from the intrinsic properties of the amalgam material itself. Because the filling is made of metal, it can conduct hot and cold temperatures resulting in some temperature sensitivity. It may also cause occasional, minute electrical flow if it comes into contact with other metals. This DOES NOT mean that you will be electrocuted. It does mean that you may feel some discomfort if you bite down on something metallic, so no chewing on tin foil! Amalgam fillings should not be used on patients with allergies to mercury, nickel, chromium, and/or beryllium alloys.
CONCERNING THE TOXICITY OF MERCURY IN DENTAL AMALGAMS: Although elemental mercury is included on the State of California’s list of chemicals known to cause reproductive toxicity, the mercury in dental amalgam fillings is emitted in minute quantities as vapor. The Food and Drug Administration (FDA) and World Health Organization (WHO) have determined that there is no scientific evidence that dental amalgams cause harm to patients except in the case of an allergy. They have even deemed it safe for use in women, children, and diabetics.
Composite Resin Fillings
Advantages: Composite resin fillings are a mixture of powdered glass (crystalline silica) and plastic resin. It can be used for fillings, inlays, veneers, partial and complete crowns, and tooth repair. One of the main advantages of composite fillings over amalgam fillings is that they are tooth colored, and much less noticeable (if at all). They are also strong and durable, and can resist breaking and damage due to biting forces. Unlike amalgam fillings, they do not corrode, and early stage tooth decay can be easily detected. This type of filling can also be performed in a single visit, and the maximum amount of tooth is preserved during restoration.
Disadvantages: Although they are durable, composite resin fillings last for much less time than amalgam fillings (about 3-7 years) and may wear faster than the surrounding dental enamel. The shrinkage of the material when it is hardened may lead to further tooth decay and temperature sensitivity. Although composite fillings only require a single visit when performed on a tooth, they do require multiple visits when used on inlays, veneers or crowns. In addition, while there is a small risk of leakage if the composite is bonded only to the tooth enamel, the filling may leak over time if it is bonded beneath the enamel layer. And most importantly to many patients, composite resin fillings cost more than amalgam fillings, both in the initial price and in the possible cost of replacement every 3-7 years.
CONCERNING THE TOXICITY OF CRYSTALLINE SILICA IN COMPOSITE FILLINGS: Crystalline Silica is included in the State of California’s list of chemicals known to cause cancer.
Hopefully, with the above information, you can make an informed decision regarding your choice of filling the next time you have to have one performed. If you have any further questions, or if you suspect that you might need a filling, give our office a call and we’ll be happy to schedule an appointment for you!