DENTAL PRACTICTIONERS have used amalgam restorations for years. Since the advent of composites and other tooth-colored restoratives, amalgam has come to be considered an old-technology material. The amalgam restoration is being pushed aside mostly for political and aesthetic reasons rather than because of scientific facts. The tooth-colored materials look better, but amalgam retains a role, and a market, in dentistry because of its lower cost (both in the cost of the material and in the cost of placement time) and because of specific performance characteristics that sometimes make amalgam the material of choice.
Permite (from SDI North America, Inc.) is one example of an amalgam that has developed its features to better meet the needs of a dental practicitioner. It is a high-silver ad-mix (50 percent lathe cut, 50 percent spherical) touted to have excellent performance and biocompatibility in the oral environment. Studies demonstrate that Permite is not affected by moisture and fluid, and in fact may expand slightly to deliver a better seal in a wet environment. Thus, Permite makes a good choice for use in retrograde seals when the use of amalgams is preferred.
The slight increase in dimensional size after setting serves to provide a superior marginal seal that should minimize microleakage, post-op sensitivity, and secondary decay in posterior restorations. The higher compressive and tensile strengths of this crunchy packing material minimize the risk of fracture and extend the lifespan of the restoration, sometimes by a factor of three to four times over composite restoration. We have all seen amalgam restorations that are thirty to forty years old, and we are surprised when a composite lasts a decade. Also, for the patient, although an almagam restoration is not as pretty, it is typically more cost-efficient and lasts much longer. Especially in these tough economic times, the benefits of amalgam for the patient may be worth considering.
The disadvantage of any amalgam is its mercury content and the association of alleged detrimental side effects of an amalgam restoration, although these side effects have never been confirmed by any clinical study. This association of mercury with long-term health concerns detracts from the benefits of placing an amalgam restoration. Mercury, if a person is exposed to it over long periods of time, could cause a wide range of harmful side-effects, such as kidney disease, stomatitis, and mental depression. However, according to the FDA, mercury in amalgam fillings has not been shown to have caused harm directly. Permite’s capsule has been designed to minimize the amount of mercury vapor released by activation, trituration, and placement.
Permite is my choice of amalgam when an amalgam is indicated. Amalgams such as Permite may provide a refreshing option, or the best choice for specific dental applications.
April - June 2011