Bleaching products brighten teeth that have been stained or darkened by food, tobacco use, injury or aging. Most bleaching products are effective, and come in a wide range of strengths. White fillings and crowns will not lighten with bleach, but natural tooth enamel will. The bleach products pull color out of the tooth enamel, similar to bleach water removing tea stain from a tablecloth. The stronger the bleach, the faster it works. Caution must be used to prevent tooth enamel from becoming translucent and grey-ish due to over-bleaching.
In-office Bleaching – Also called power bleaching, this is done in a dental office with protective covering on gums so that the gum tissue doesn’t get burned. Typically a 36% bleach gel is placed on the enamel, and sometimes a light is shined on the teeth. It is important that the teeth be checked first and all cavities filled so that the teeth are not damaged by the process. Multiple appointments may be necessary to achieve the desired whiteness. It is not uncommon to have temporary sensitivity to cold after power bleaching.
Custom-Fitted Bleach Trays – Impressions are made at the dental office so that flexible custom-fit clear trays can be made for covering the teeth. The patient receives several containers of the bleaching gel. The gel is applied to the teeth at home, using the trays, which are worn for about an hour once or twice a day. The bleach solution can vary from 10% to 30%. The trays can be used indefinitely, allowing for ongoing bleaching or occasional touch-ups. This method is considered to be cost-effective and easy to control.
Over-the-counter products – These include toothpastes, bleaching strips, and rinses, as well as one-size fits all trays. Whitening toothpastes often remove just the surface stain with mild abrasives, and are easily diluted with saliva. Whitening strips are pressed onto the teeth and can be effective over a period of time. The strengths of these products is usually around 5%, so it takes longer to get the desired whiteness. Most over-the-counter products are good for younger people or for those who already have white teeth.
A combination of in-office bleaching and custom-fitted trays is an especially effective way to achieve white teeth and then maintain the whiteness over time.