Posts for tag: fillings
It takes a lot of skill, experience, talent and artistry to create tooth restorations that look so natural that no one can tell them apart from the originals. To do so requires understanding of the normal anatomy of a tooth as well as of the interactions of light and color.
How the anatomy of a tooth determines color
The color that we perceive when looking at a tooth results from the combined appearance of the tooth’s center core (dentin layer) and its covering enamel. Going from the outside in, the enamel is made of tightly packed crystals of calcium, which cause it to be one of the hardest substances naturally produced by animals. The crystals are also responsible for a tooth’s brilliance and translucence. The dentin is more like bone, a porous living tissue composed of microscopic tubes, interspersed with more calcium crystals. In the very center of the tooth is a central chamber containing the pulp and nerves.
Each of these layers has its own physical and optical properties. Since the enamel is translucent and the dentin is more opaque, most of the tooth’s color comes from the dentin and is transmitted through the enamel layer. Factors that affect this transmission include the thickness and age of the enamel as well as external tooth whitening.
If the enamel is more translucent, more of the color of the dentin shows through. If it is more opaque, the enamel absorbs and reflects light so that less color is visible and the enamel looks brighter.
The language of color composition and reflected light
Color means the whole spectrum in the rainbow. The spectrum is made up of the three primary colors — red, blue, and green. When all are combined, they create white light.
Hue refers to the brightest forms of the colors. The color we perceive depends on the dominant wavelength of light that is reflected by an object.
Value refers to a color’s lightness or darkness. A brighter color has a higher value.
Chroma is the amount of identifiable hue in a color. An achromatic color (without hue) appears gray.
Saturation is a measure of a color’s intensity.
This terminology of color is used not only by dentists and dental technicians, but also by a wide range of artists. It implies expertise and understanding of how colors work, how they vary and change and affect one another.
Contact us today to schedule an appointment or to discuss your questions about bonding to repair chipped teeth. You can also learn more by reading the Dear Doctor article, “Artistic Repair of Front Teeth with Composite Resin.”
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?”
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?”