Posts for: February, 2015
When you have your teeth bleached in a dental office, the results almost seem like magic. Let's push aside the magician's cape and see what is really happening in professionally-applied, in-office tooth whitening.
How do teeth become discolored?
A tooth's enamel covering is mostly composed of mineral crystals. At a microscopic level, you can see a framework or matrix of organic (living) matter interspersed between the crystals of enamel creating a very irregular surface capable of retaining stains. Chromagenic (color generating) organic compounds can become part of this organic matrix resulting in tooth staining. They can be bleached without affecting the mineral structure of the tooth's enamel.
As people get older and their teeth wear, the enamel loses its youthful translucency and the underlying layer, called dentin, thickens and becomes more yellow. Such changes to the actual tooth structure are called intrinsic staining. Other causes of intrinsic discoloration are exposure to high levels of fluoride or tetracycline antibiotic administration during childhood, tooth decay, or root canal problems, among others. Discoloration can also be caused by external staining from certain foods, drinks, or tobacco products. Such surface stains are called extrinsic staining.
Behind the Magic
Materials used for tooth bleaching are hydrogen peroxide and carbamide peroxide. Peroxides are commonly used as bleach, and you may have seen them used as hair bleaches, for example. Hydrogen peroxide is a strong oxidizing agent that attacks the organic molecules responsible for tooth discoloration, bleaching them until they lose their color. Carbamide peroxide also contains urea, which is a compound that permits the peroxide to remain in contact with the teeth for longer amounts of time without harming them.
Often called power bleaching, the in-office technique uses a high concentration of peroxide solution (35-45% hydrogen peroxide), placed directly on the teeth in the form of a gel. A heat or light source may enhance the peroxide release. The gel is applied with trays custom fitted to your mouth, and specific barriers are applied to protect sensitive gum tissue from the solution. Results show teeth becoming up to ten shades lighter in about an hour.
In-office bleaching under the supervision of my staff and me is recommended if you have severely stained teeth, and particularly if you are about to have veneers or crowns made. It's a way to rediscover the pearly translucency of your youthful smile.
Not long ago, Glee star Lea Michele had all of her wisdom teeth removed. This is a very common procedure that people in their twenties, like Michele, often undergo to prevent serious dental problems down the road. The actress found that the procedure really was actually not very difficult to tolerate.
“Feeling all better from my surgery!” she tweeted to fans a few days later. “Back to work tomorrow.”
Why do wisdom teeth so often cause problems? For one thing, they come in years later than the other 28 permanent teeth — usually between the ages of 17 and 25. By that time, there is often no room in the jaw to accommodate them. As man has evolved, the jaws have actually become smaller in size — often creating a lack of space for the wisdom teeth to erupt into proper position. If wisdom teeth become blocked (impacted) by other molars that are already there, infection and damage to neighboring teeth may result.
Sometimes the wisdom teeth themselves cause the problem by growing in at an odd angle. They push against other teeth, often compromising the adjacent tooth's supporting bone. While you would think pain would occur if any of these problems were present, that does not always alert us to a wisdom-tooth problem. It's usually diagnosed with the help of x-rays.
Wisdom tooth extraction is often performed in the dental office using a local anesthetic (numbing shot) to keep you from experiencing any pain, along with conscious sedation to help you relax. The type of anesthesia that's best for you will be determined before the procedure.
After we gently remove the tooth or teeth, you may need to have the site sutured (stitched) to promote healing. You will rest for a short time before going home, and may need to have someone drive you, depending on what type of anesthesia you were given.
Once you get home, you should apply an ice pack on the outside of your cheek for about five minutes on, five minutes off for as many hours as possible to help reduce any postoperative swelling on the first day. Starting on the second day, the warm moist heat of a washcloth placed on the cheek and hot salt water rinses will make you more comfortable. You may want to eat soft foods and brush your teeth very carefully during the recovery period, which lasts only a few days as Lea Michele discovered. Before you know it, you'll be “feeling all better!”