Considering whitening your teeth? Can you over whiten your teeth? Before you do, discuss the possible risks with your dentist – especially if you plan to whiten your teeth using an at-home bleaching system. Risks associated with tooth whitening include tooth sensitivity and damage to the roots of teeth. Dentists may be able to predict if you will have problems with or sensitivities to the procedure. They also may be able to help you alleviate sensitivity by recommending certain procedures and toothpastes designed to treat sensitive teeth. Dentists can also check for signs of root damage caused by tooth whitening and treat the condition if detected in time. Why do teeth change color and become darker or more yellow? The internal portion of teeth normally darkens over time. In addition, personal habits – such as tobacco use or drinking coffee, tea or wine – can cause staining. Certain medications also can discolor teeth. Teeth cleaning by your dental office can often remove any external stains – and it promotes good oral health. Be sure to visit your dentist for a thorough cleaning and examination before you decide to whiten your teeth. You may find that a professional cleaning is all it takes to give you a whiter, brighter smile. Generally, tooth whitening is successful in at least 90 percent of patients. As a rule of thumb, yellow-colored teeth respond well to whitening, while brownish-colored teeth don’t respond as well. Gray stains caused by smoking, taking tetracycline or fluorosis (ingestion of too much fluoride) most likely will not be dramatically changed by tooth whitening. Likewise, tooth whitening may not enhance your smile if you’ve had bonding or tooth-colored fillings placed in your front teeth. The whitener will not affect the color of these materials, and they will not match your newly whitened smile. In these cases, you may want to investigate other options, such as porcelain veneers or dental bonding on other teeth.