Emily Jolly doesn't mind admitting that she loves her teeth.
The 24-year-old Fort Collins resident has a mouthful of straight, white teeth thanks to orthodontic work and what she calls "religious" efforts to whiten them.
So she decided to try one of the many methods available for whitening teeth. She started with an over-the-counter product, Crest White Strips.
"My results were amazing," she said. "It was very nontypical. I would not have to use them as often as they say to use them."
But not everyone can expect those kinds of results from over-the-counter products, said Dr. John J. Hanck, a Fort Collins dentist and president of the Colorado Dental Association.
"Some people have good results. It depends on the person and the density of the enamel of the tooth," Hanck said.
Some people prefer to call in the big guns - professional whitening techniques. There are a range of choices that some dentists offer, including professional-strength whitening strips, custom-made trays and in-office treatments such as Bright Smile, which uses a light to accelerate the work of the whitening agent.
Teeth begin to yellow over time because as teeth age, the enamel wears thinner and the dentin, which is below the enamel, darkens, said Hanck. Dark liquids and food and tobacco also can stain teeth, but a professional polishing often can erase the stains, he said.
All whitening methods work in essentially the same way, by applying a hydrogen peroxide solution to the teeth that brightens them through oxidation. The higher the concentration of peroxide in the product, the faster the whitening agent will work but the greater the risk of tooth sensitivity and gum irritation.
"First of all, they are all safe. It doesn't hurt the enamel. With some of the stronger ones, you might get some mild gum irritation. ... And some can make the teeth sensitive," Hanck said.
Gum irritation and tooth sensitivity is temporary, he said.
Here are some things to consider before you whiten:
Consult your dentist to determine if you are a good candidate for whitening, said Valerie Miller, a local dental hygienist who does consultations for teeth whitening at the office of Dr. Steven J. Koehler Family and Cosmetic Dentistry.
Whitening products will not work on existing restorative work such as caps, veneers or bonds.
Have a realistic goal for how white your teeth should be. "What can be done can be overdone," Hanck said. "The teeth are not supposed to be brighter than the whites of the eyes. When the teeth get so white, it distracts from the balance, harmony and beauty or handsomeness of the face."
Whitening products do not work well on gray teeth or discoloration caused by trauma, Hanck said. For some, graying was caused by the use of the antibiotic tetracycline as a child.