Laser-Assisted
Periodontal Therapy

Don't Bleach Until You See the White of Their Eyes

When my 16-year-old daughter came to me and said she wanted to bleach her teeth, it didn't take more than a fraction of a second for me to respond, "You're too young." That is one of the great universal responses that parents have the privilege of giving when they can't come up with a more solid response. I backed it up by saying that she had a beautiful smile (especially after 3 years of orthodontic treatment) and that her teeth didn't look as yellow as she was convinced they were.

Of course, she was expecting a different response. "How can you say "No"?" she asked. "Your business is to help people look better and feel better about themselves by making their teeth look beautiful! How come you will help other people, but you won't help me?" I was being hit with the sound logic and the "I thought you loved me" reasoning of a teenager whose entire social status, self-esteem, and family bond was in the balance and entirely based on the desire to go from a tooth shade of A-2 to A-0. As any father knows the power of tears welling up in a daughter's eyes, I came up with the second most used universal response: "Okay, I'll think about it." Then came her "knock-out punch," a kiss on the cheek and "Thanks, Daddy. You're the best!"

Having bought myself some valuable time and knowing full well that I would have to give in eventually, I decided to do some research on the most current bleaching systems on the market, as well as talk to our personal dentist and some of my dentist clients for their recommendations. My greatest concerns were the potential for tooth sensitivity on someone her age and the possibility that she would overdo the process. Since in-home bleaching kits were introduced, I have seen an increasing number of patients for custom shades who I feel have overbleached. Some people's teeth appear so white and bright that they become the focal point of their face. I also have seen patients whose natural tooth color appeared to have been almost completely removed by overbleaching, leaving a transparent violet result. Of course, as a hair stylist focuses on other people's hair, a fitness trainer focuses on a person's physique, and someone in the clothing industry evaluates a person's outfit, those of us involved in dentistry generally first notice people's teeth when we see them. What may appear less than ideal to us may be exactly what the patient wanted. However, the patient should be educated about where to draw the line in the bleaching process.

Most importantly, a person's face should be seen as a complete entity. The face is made up of the eyes, the mouth, the nose, cheekbones, forehead, mouth, chin, hair (or the lack of), and ears. By nature, a balance of features exists: eyes equidistant from each other, the nose centered between them, the mouth directly below, and the ears at the same level with each other. Variations in size and shape create individuality and keep us all from being confused about who is who. We mainly recognize each other by our entire face, not just by one feature (Cyrano de Bergerac excluded). The teeth and smile should only be part of the picture, not fill the entire frame.

Next, from a restorative perspective, it usually is more difficult for a ceramist to create a natural-looking restoration that accurately matches excessively bleached teeth in hue, chroma, value, and specially translucency. Although more bleached shade guides are being introduced into the profession, the ability to match the vitality of bleached natural teeth remains a challenge. To create whiter and higher value shades, higher opacity pigments are introduced, diminishing light transmission and increasing reflectance.

As a result of the increase in opacity, the problem of metamerism is magnified, especially regarding porcelain-to-metal restorations where light transmission is already limited by the opaqued metal understructure. All-ceramic restorations naturally allow a greater amount of light transmission but are limited in their ability to mask out a dark or discolored preparation. New generations of millable ceramic core materials and high-strength lithium disilicate pressable cores are now available, offering greater degrees of masking ability for those teeth that do not respond effectively to the bleaching process before preparation. Even with the new core materials, the manufacturing of "out-of-the-bottle" porcelain bleached shade powders that can be applied to both metal and ceramic substructures is limited. If the limitations of bleached shade guides and the lack of bleached porcelain powders are combined with the inability to predetermine the final shade that each patient will achieve from the bleaching process, the restorative shade-matching procedure becomes specialized and, unfortunately, somewhat unpredictable

To minimize the variables in the bleaching process, standards and patient education need to be established. When I finally gave in to my daughter (I presented her with a home bleaching kit on her 17th birthday), I explained to her that people need to focus on her entire face, not just her teeth. I also told her not everyone needs to go "7 to 11 shades lighter" as some advertisements claim. Then she asked the ultimate question, "How do I know when to stop?" The answer I gave her was, "When your teeth match the white of your eyes." The eyes and the smile work together. A natural balance between the 2 needs to be maintained. If a person's teeth are so white that they dominate the face, the beauty of the eyes is lost. After I set this standard for her, I began to look more closely at people who I could tell had bleached their teeth. In my opinion, the most attractive and natural look was evident when the shade of the teeth and the sclera of the eyes were in harmony.

Regarding restorative technique, I recommend that the ceramist first select the basic bleached shade that most closely matches the patient's teeth for the primary build-up. The proper value and the creation of vitality can be achieved by completely overlaying the bleached dentin porcelain with enamel. The total overlay of enamel creates a higher degree of light transmission before it is reflected off of the bleached dentin, which ultimately passes through the enamel as it exits the surface, creating a more vital-looking restoration.

It only took a few days for my daughter's teeth to lighten to "our" predetermined goal. Her desire for whiter and brighter teeth was justified when I recognized the natural balance between her smile and her eyes. She is in college now and tells me how guys always introduce themselves to her. I told her to start drinking more tea.

Source: Compendium - June 2004. Author: Bill Mrazek, BS, CDT, Mrazek Prosthodontics, Ltd.