Fillings are the most common form of dental restoration for decayed or chipped teeth. Fillings are direct restorations that are placed immediately into a prepared cavity in a single visit. They include Composite (tooth colored) fillings, glass and resin ionomers, and dental amalgam.
Thanks to advances in modern dental materials and techniques, we have more ways to create pleasing, natural-looking smiles. As a result, there are several choices when it comes to selecting materials to repair worn, damaged or decayed teeth. However, these new materials have not eliminated the usefulness of more traditional dental materials, such as gold, base metal alloys and dental amalgam. That’s because the strength and durability of traditional dental materials continue to make them useful for certain situations, such as fillings in the back teeth where chewing forces are greatest.
Composite (Tooth Colored) Fillings
Composite fillings are the most esthetic direct restoration filling option, however are not always appropriate for use everywhere. Composites are a mixture of glass or quartz filler in a resin medium that produces a tooth-colored filling. Composite fillings provide good durability and resistance to fracture in small-to-mid size restorations that need to withstand moderate chewing pressure. Often less tooth structure is removed when preparing the tooth, and this may result in a smaller filling than that of an amalgam. As a result, composites often allow a more conservative repair to the tooth.
However, composite fillings require a cavity that can be kept clean and dry during filling and it should be noted that they are subject to stain and discoloration over time. Furthermore, studies show that composite fillings do not last as long as traditional dental amalgam fillings, particularly in high stress areas of the mouth such as posterior biting surfaces.
Because of the limitations to the use of composite fillings, some patients consider other restorative measures when necessary. If esthetics are an issue, options include porcelain inlays and onlays , and crowns. If esthetics is not a concern, patients often select a less expensive restorative option such as traditional amalgam fillings.
Dr. Victor can discuss the appropriateness of composites and their alternatives with you for each of your restorative needs.
Glass and Resin Ionomers
Glass ionomers are translucent, tooth-colored materials made of a mixture of acrylic acids and fine glass powders that are used to fill cavities, particularly those on the root surfaces of teeth. One of the benefits of glass ionomers is that they can release a small amount of fluoride that may be particularly helpful for patients who are at high risk for decay. Like composite fillings, it is often possible to conserve tooth structure by using a glass ionomer filling as compared to amalgam fillings.
However, Glass ionomers have a low resistance to fracture. Therefore, they are primarily used in areas not subject to heavy chewing pressure, such as mostly used in small non-load bearing fillings or on the roots of teeth.
Resin ionomers are made from glass filler with acrylic acids and acrylic resin. They also are used for very small, non-load bearing fillings (between the teeth), on the root surfaces of teeth, and they have low to moderate resistance to fracture.
Ionomers experience high wear when placed on chewing surfaces. Both glass and resin ionomers mimic natural tooth color but lack the natural translucency of enamel. Both types are well tolerated by patients with only rare occurrences of allergic response.
When esthetics is not a concern, traditional dental amalgam fillings can be an excellent restorative choice. Used by dentists for more than a century, it is the most thoroughly researched and tested restorative material among all those in use. It is durable, easy to use, highly resistant to wear and relatively inexpensive in comparison to other materials. For those reasons, it remains a valued treatment option for patients.
Dental amalgam is a stable alloy made by combining elemental mercury, silver, tin, copper and possibly other metallic elements. Although dental amalgam continues to be a safe, commonly used restorative material, some concern has been raised because of its mercury content. However, the mercury in amalgam combines with other metals to render it stable and safe for use in filling teeth.
While questions have arisen about the safety of dental amalgam relating to its mercury content, the major U.S. and international scientific and health bodies, including the National Institutes of Health, the U.S. Public Health Service, the Centers for Disease Control and Prevention, the Food and Drug Administration and the World Health Organization, among others have been satisfied that dental amalgam is a safe, reliable and effective restorative material.
Because amalgam fillings can withstand very high chewing loads, they are particularly useful for restoring molars in the back of the mouth where chewing load is the greatest. They are also useful in areas where a cavity preparation is difficult to keep dry during the filling replacement, such as in deep fillings below the gum line. Amalgam fillings, like other filling materials, are considered biocompatible—they are well tolerated by patients with only rare occurrences of allergic response.
Disadvantages of amalgam include possible short-term sensitivity to hot or cold after the filling is placed. The silver-colored filling is not as natural looking as one that is tooth-colored, especially when the restoration is near the front of the mouth, and may showswhen the patient laughs or speaks. And to prepare the tooth, the dentist may need to remove more tooth structure to accommodate an amalgam filling than for other types of fillings.
Because of the concern about dental amalgams, much of the content of this page came directly from the American Dental Association’s website on amalgam fillings.