Posts for tag: fillings
With all the new tooth-colored fillings for cavities, it's easy to overlook metal amalgam. While this mainstay of dental care for over a century might not be as attractive as composite resins or glass and resin ionomers, it still has the advantage of strength and durability.
Amalgam is a stable metal alloy usually made up of silver, tin, copper and mercury. The metals are proportioned and mixed precisely to guard against “free” mercury molecules, which could pose a health hazard. The mixture is pliable at first, but then sets hard once molded into the prepared area of the tooth.
Besides strength, amalgam's other advantages include low cost, high resistance to wear and biocompatibility (not toxic to the body or allergy-producing). At the same time, it can require more tooth structure removal to accommodate a filling and cause higher sensitivity to temperature for a while after installation. Its main disadvantage, however, is appearance — it's now considered unacceptable from an aesthetic point of view to use it in visible areas like the front teeth.
Because of this, materials resembling natural tooth color are coming into vogue, especially as their strength improves. Still, dental amalgam continues to play a useful role, especially in less visible back teeth with higher chewing forces.
One past concern about dental amalgam is the inclusion of mercury in the alloy. As mentioned before, mercury is hazardous in a “free” form when not knit microscopically with other metals; as such it can emit a vapor that could enter the bloodstream and damage the nervous system. But after several studies by various organizations, the American Dental Association has concluded amalgam's precise mixture prevents the mercury from taking this form: although some vapor is given off during chewing it's far too low in concentration to pose any danger.
Dental amalgam continues to be an effective choice for fillings. Whether it's the right choice for you will depend on the type and location of a tooth to be filled, and whether durability is a higher concern than appearance. If we do recommend an amalgam filling, you can be assured it's a safe and lasting choice.
If you would like more information on your choices for dental fillings, please contact us or schedule an appointment for a consultation. You can also learn more about this topic by reading the Dear Doctor magazine article “Silver Fillings — Safe or Unsafe?”
Over the last century and a half millions of people have had a tooth cavity filled with “silver” amalgam. Perhaps you’re one of them. The use of this effective and durable filling has declined in recent years, but only because of the development of more attractive tooth-colored materials.
At the same time there’s another issue that’s been brewing in recent years about this otherwise dependable metal alloy: the inclusion of mercury in amalgam, about half of its starting mixture. Various studies have shown mercury exposure can have a cumulative toxic effect on humans. As a result, you may already be heeding warnings to limit certain seafood in your diet.
So, should you be equally concerned about amalgam fillings — even going so far as to have any existing ones removed?
Before taking such a drastic step, let’s look at the facts. To begin with, not all forms of mercury are equally toxic. The form causing the most concern is called methylmercury, a compound formed when mercury released in the environment combines with organic molecules. This is the form certain large fish like salmon and tuna ingest, which we then ingest when we eat them. Methylmercury can accumulate in the body’s tissues where at high levels it can damage various organ systems.
Dental amalgam, on the other hand, uses elemental mercury. Dentists take it in liquid form and mix it with a powder of other metals like silver, tin and copper to create a pliable paste. After it’s placed in a prepared cavity, the amalgam hardens into a compound in which the mercury interlaces with the other metals and becomes “trapped.”
Although over time the filling may emit trace amounts of mercury vapor, it’s well below harmful levels. You’re more likely to encounter “un-trapped” mercury in your diet than from a dental filling. And scores of studies over amalgam’s 150-year history have produced no demonstrable ill effects due to mercury.
Although it now competes with more attractive materials, amalgam still fills (no pun intended) a necessary role. Dentists frequently use amalgam in less visible back teeth, which encounter higher chewing pressures than front teeth. So, if you already have an amalgam filling or we recommend one to you, relax — you’re really in no danger of mercury poisoning.
One of the top concerns in public health today is exposure to the metallic element mercury within the environment. At abnormal levels, mercury can have a toxic effect on our nervous systems and cause other health problems.
These concerns over mercury have also increased attention on one material in dentistry that has included the metal in its makeup for over a century — dental amalgam for filling teeth. Amalgam is a metal alloy that can include, in addition to mercury, silver, tin, and copper. When first mixed dental amalgam is a moldable material used for fillings in prepared teeth. It then hardens into a durable restoration that can withstand biting forces.
While the use of amalgam has declined with the introduction of life-like colored fillings, it's still used for teeth like molars subject to high biting forces. With what we now know about the ill effects of mercury (which can make up to half of an amalgam mixture) is it safe to continue its use?
The American Dental Association has performed extensive research into amalgam safety. They've found that mercury is stabilized by the other metals in the amalgam. This prevents "free" molecules of mercury, the real source of harm to health, from escaping into the blood stream in the form of vapor. Although trace amounts of mercury vapor from the amalgam are released as a person chews, those levels are well below the threshold that could cause harm.
From a patient standpoint, the biggest drawback to dental amalgam isn't safety — it's the appearance of teeth it's used on. Silver fillings aren't considered attractive. And now there are viable filling alternatives that not only look like natural teeth but can withstand biting forces almost as well as amalgam. These materials include composite resins, mixtures of glass or quartz within resin, or glass and resin ionomers. Each of these has advantages and disadvantages depending on how and where they're applied.
After a thorough dental examination, we'll be able to advise you on what filling material will work best to produce the best result. And if we do suggest dental amalgam you can rest assured it will be a safe choice.
If you would like more information on the safety of dental amalgam, please contact us or schedule an appointment for a consultation. You can also learn more about this topic by reading the Dear Doctor magazine article “Silver Fillings — Safe or Unsafe?”
Metal amalgam fillings for dental caries have been used since the mid 19th Century. Although newer, “natural color” filling materials have become available, amalgam remains a standard choice among dentists.
Dental amalgam is a metal alloy created by carefully combining exact proportions of mercury, silver, tin and copper. Though quite pliable when first mixed, the alloy eventually sets into a very hard substance that stands up well against the forces produced by the mouth’s natural chewing function. The presence of mercury, however, has raised concerns for some that the metal’s toxic properties pose a risk to the patient’s health.
But after decades of research, the American Dental Association and other health organizations have concluded that dental amalgam “is a safe, reliable and effective restorative material.” Studies have determined that any free molecules of mercury that could potentially enter the bloodstream are trapped in the set amalgam. And although the amalgam can release mercury vapor during chewing, the amounts are well below the levels considered harmful.
Dental amalgam has proven to be versatile, effective and economical. It doesn’t create an allergic reaction, is quite durable, and doesn’t interfere with normal chewing function. It does, however, have its drawbacks. Its use can require more tooth material to be removed to keep the fillings in place, and they can increase temperature sensitivity during the initial four to six weeks. And, of course, their metallic appearance, especially when used in more visible front teeth, reduces their aesthetic appeal.
Other, more cosmetically appealing types of filling material have been developed over the years. These include composite resin fillings, a mixture of glass or quartz in a resin medium; glass ionomers, made of acrylic acids and fine glass powders and best used in areas not subject to heavy chewing; and resin ionomers, similar to glass ionomers but with the addition of acrylic resin. Each of these has their advantages and disadvantages (as well as cost considerations), but they’re main advantage over amalgam is their mimicry of natural tooth color.
The choice of either dental amalgam filling or one of the tooth-color alternatives depends on what you may need and can afford. Rest assured, though, that if the choice is dental amalgam, this restoration workhorse can provide you years of safe and effective service.
If you would like more information on your options for tooth fillings, please contact us or schedule an appointment for a consultation. You can also learn more about this topic by reading the Dear Doctor magazine article “Silver Fillings.”