SIDE EFFECTS:
TOOTH SENSITIVITY: Although uncommon, some people can experience some tooth sensitivity during the first 24 - 48 hours after the whitening treatment. People with existing sensitivity, recently cracked teeth, micro-cracks, open cavities, leaking fillings, or other dental conditions that cause sensitivity may find that these conditions increase or prolong tooth sensitivity after the treatment. If you experience tooth sensitivity after the treatment, you can use SensodyneTM toothpaste to ease the discomfort. Brush your teeth with this toothpaste until tooth sensitivity goes away.
If you have tooth sensitivity do not begin with your touch-up pen treatment at home. Wait until the sensitivity goes away and then begin with the home treatment.
RELAPSE: After the treatment, it is natural for teeth color to regress somewhat over time. This is normal and should be very gradual, but it can be accelerated by exposing the teeth to various staining agents, such as coffee, tea, tobacco, red wine, colas, citrus drinks and fruits, etc. Do not eat or drink anything except water for the first hour after the treatment because the gel opens the pores of the enamel and makes the teeth very vulnerable to staining agents. If you purchased a touch-up pen or a take-home kit, be aware that the pores of your enamel will remain open for as long as you use it so you should refrain from staining agents till you stop using the pen. You can resume your normal habits 24 hours after treatment. Also, be aware that drinks and food are not the only things that can stain our teeth when the pores are open; lipstick, for example, can stain too. Do NOT apply lipstick soon after whitening your teeth.
ALLERGY: Some people are allergic to peroxide but are not aware of it. If you had the treatment done and a few hours or a day later you have a blister on your lips, you are probably having an allergic reaction to the gel. Buy liquid vitamin E in any drugstore and apply it to the blister until it goes away. It generally goes away within a couple of days by itself anyway. You can also take any over-the-counter antihistamine.
RESULTS:
How long the results will last depends on 2 main factors: 1) your habits, and 2) the porosity of your teeth. If you expose your teeth to staining agents such as tobacco, coffee, red wine, tea, colas, etc. on a regular basis, your whitening results will not last as long. If you have naturally porous enamel, your teeth will be more vulnerable to staining agents and your teeth will get stained again sooner than the average person.
Unfortunately, there is no way of knowing ahead of time how porous your teeth are.