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.”
Recently, a number of new filling materials that mimic tooth color have come into popular use and, so far, have proven more durable than past versions. Even so, the traditional metal-based dental amalgam remains a viable choice, especially for less visible back teeth and their higher biting forces.
Used for more than a century, dental amalgam is a metal alloy composed of silver, mercury, tin and copper. The mixture is carefully proportioned so that potentially hazardous mercury is kept to a minimum and bonded with the other metals. Amalgam in its initial form is quite pliable so that it can be molded into the tooth structure under repair. Afterward it sets hard to form a durable filling that can withstand the daily force generated when we bite and chew food.
Besides durability, dental amalgam rarely causes an allergic reaction in a patient, and it’s easy for trained dentists to apply. On the downside, however, it can cause temporary temperature sensitivity in the tooth just after filling, and the tooth itself may require some removal of healthy structure to help keep the filling in place. And from an aesthetic point of view, its metallic appearance is considered unattractive especially for front teeth.
The presence of mercury in amalgam has also raised concerns over the years. “Free” mercury — atoms that escape through vapor emitted by the metal — can enter the bloodstream and potentially harm the nervous system. But after extensive study and research, U.S. and international health bodies including the American Dental Association have concluded any free mercury released during chewing is extremely low and well below any harmful levels. These studies have also found no ill effects in either children or adults with dental amalgam fillings.
Deciding on the type of filling material to use — dental amalgam or a newer composite resin, resin ionomer or glass ionomer — depends on a number of factors including the location of the teeth to be filled, the extent of decay and your personal preferences. Taking these into account, we’ll be happy to discuss which type of filling will suit you best for repairing decayed teeth.
If you would like more information on filling material options including 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?”
Are tooth-colored fillings safer than silver fillings?
No. Both are considered safe based on the most reliable and up-to-date scientific evidence. Still, tooth-colored fillings do have some definite advantages. Not only do they blend in with your smile far better than “silver” (dental amalgam) fillings, but they often require less removal of healthy tooth structure. That’s because in order to fill a tooth with amalgam, it is necessary to create indentations in the tooth called “undercuts” to hold the amalgam in; this requires the removal of some healthy tooth material. With a tooth-colored filling, we need only remove the decayed part of the tooth to place the filling.
Are there any disadvantages?
Yes, tooth-colored fillings don’t always wear as well as metal fillings — particularly on back molars where they are subjected to the most stress from chewing. They are also more expensive and less likely to be fully reimbursed under dental insurance plans.
Are there different types of tooth-colored fillings?
Yes, three different choices of tooth-colored fillings are available:
- Composite — This mixture of plastic and glass is the most common type of tooth-colored filling. Newer materials can hold up almost as long as amalgam fillings and look very natural, though they can stain over time just as natural teeth do.
- Porcelain — High-tech dental ceramics are considered the most aesthetic choice of filling material. They don’t stain as composites can, but their relatively high glass content can make them more brittle and prone to breakage. They may be more expensive than composites.
- Glass Ionomer — Made of acrylic and glass powders, these inexpensive, translucent fillings blend in acceptably well with natural teeth and have the advantage of releasing small amounts of fluoride to help prevent decay. However, they generally don’t last as long as other restorative materials.
We would be happy to offer guidance on which choice would be best in your own unique situation.
If you have any questions about tooth-colored fillings, please contact us or schedule an appointment for a consultation. You can learn more by reading the Dear Doctor magazine article “The Natural Beauty of Tooth-Colored Fillings.”