Posts for: October, 2017
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.”
You’ve invested a lot of time and money in orthodontic treatment to improve your smile. If you’re not careful, though, your teeth could actually move back to their old positions. The reason why is related to the same natural tooth-moving mechanism we use to straighten teeth in the first place.
Teeth are held in place by an elastic, fibrous tissue called the periodontal ligament lying between the teeth and the jawbone and attaching to both with tiny collagen fibers. The periodontal ligament allows for incremental tooth movement in response to pressure generated around the teeth, as when we chew (or while wearing braces).
Unfortunately, this process can work in reverse. Out of a kind of “muscle memory,” the teeth can revert to the older positions once there’s no more pressure from the removed braces. You could eventually be right back where you started.
To avoid this, we have to employ measures to hold or “retain” the teeth in their new positions for some time after the braces come off. That’s why we have you wear a dental appliance called a retainer, which maintains tooth position to prevent a relapse. Depending on what’s best for your situation, this could be a removable retainer or one that’s fixed to the teeth.
Patients typically wear a retainer around the clock in the immediate period after braces, and then eventually taper off to just nighttime wear. Younger patients must wear one for several months until the new teeth positions become more secure and the chances of a rebound diminish. For older patients who’ve matured past the jaw development stage, though, wearing a retainer may be a permanent necessity to protect their smile.
Retainer wear can be an annoyance, but it’s an absolute necessity. Think of it as insurance on your investment in a new, more attractive smile.
If you would like more information on improving your smile through orthodontics, 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 “The Importance of Orthodontic Retainers.”