Faqs of BLEACHING
What Factors Affect the Color of My Teeth?
Some people are born with teeth that are more yellow than others. Others have teeth that yellow with age. Your natural tooth color can also be affected by many factors. Surface stains (called extrinsic stains by dentists) and discoloration can be caused by:
- Tobacco (whether smoked or chewed)
- Drinking coffee, tea, or red wine
- Eating highly pigmented foods such as cherries and blueberries
- Accumulation of tartar deposits, which result from plaque that has hardened
Internal stains (called intrinsic stains by dentists) can be caused by:
- Treatment with the antibiotic tetracycline during the time when teeth are forming
- Yellowing or graying of the teeth as part of the aging process
- Trauma to the teeth that may result in the death of the tooth's nerve, giving the tooth a brown, gray or black color
- Ingesting too much fluoride when teeth are forming (from birth to age 16), which gives teeth a "mottled" look.
What are Ways to Whiten Teeth?
Thorough cleanings by a dentist or hygienist will remove most external staining caused by food and tobacco. Using a whitening toothpaste can also help remove these surface stains between dental visits. If stains have been present for years, you may need to have your teeth professionally whitened to remove these more stubborn external stains.
Internal stains can be bleached, bonded or capped (crowned). While each of these methods is safe and effective, your dentist will recommend which treatment is appropriate for you depending on the state of your teeth and the results that you wish to achieve. Your dentist will consider:
- The degree and type of staining
- How much of the tooth structure is remaining (Is the tooth heavily filled? Are changes to the shape of the teeth needed or desired?)
How Does Tooth Whitening Work?
Whitening (bleaching) can be done either in a dentist's office or at home, using a system dispensed by your dentist. Both methods use tooth-bleaching gels that oxidize out the stain. It's not uncommon for teeth to become slightly sensitive during the whitening process.
- At-home whitening
At-home whitening is the more popular approach today. Your dentist takes an impression of your teeth and makes a custom-fitted tray, which you fill with a whitening gel and wear up to two hours daily or at night for about two weeks. Many whitening kits prescribed by dentists today contain a solution of 10-15% carbamoyl peroxide. When done under the supervision of your dentist, at-home whitening is very effective.
- In-office whitening
Less frequent and more expensive, this procedure takes from 30 minutes to one hour per visit, and you may have to return for several visits to achieve the desired whiteness. To protect your mouth, a gel-like substance may be applied to your gums and a rubber "shield" may be placed around the necks of the teeth. An oxidizing agent (the bleaching solution) is then applied to your teeth. Sometimes, a special light is used at five-minute intervals to help activate the whitening agent.
Will My Newly Whitened Teeth Stain?
Any tooth can stain, including the veneers and bonds mentioned above. To help prevent stains from coming back, avoid smoking, coffee, tea, red wine and heavily colored foods. And brush your teeth twice a day with whitening toothpaste.
How Does Bonding Work?
Bonding uses composite resins or porcelain/composite veneers to cover the surface of stained teeth and give a nice, even appearance to broken or misshapen teeth. There are two basic bonding techniques:
- Composite bonding
First, the front of the tooth is slightly reduced to prevent the "new" tooth from being too bulky. Microscopic grooves are then etched into the tooth surface with a mild acid. A composite resin matched to the color of the surrounding teeth is applied to the tooth, contoured into shape, set using a curing light, and finally smoothed and polished.
- Veneer bonding
A veneer is made to match the colour and shape of your tooth. Porcelain veneers are generally stronger, while composite veneers are less expensive. With porcelain veneers, the dentist takes an impression of the tooth and sends it to the dental lab for fabrication of the veneer, usually after the front of the tooth has been reduced. With either method, the tooth is prepared for bonding by roughening the front surface with mild etching solution. The veneer can then be bonded to your tooth using a dental bonding cement.
While more expensive, a porcelain veneer offers a better colour match to your surrounding teeth and typically lasts for five to ten years.

Why should I whiten my teeth?
Maybe you've always wanted a beautiful white smile. Or your teeth have yellowed over time. Or you're not happy with the staining that results from drinking coffee, tea, or cola. Whatever your reason for wanting whiter teeth, you're not alone.
Just like we all have different hair and skin color, people also have different tooth color. Some teeth are more yellow than others, while others yellow with aging. Your natural tooth color can also be affected by many factors.
Surface stains and internal discoloration can be caused by:
- The natural aging process
- Using tobacco (smoked or chewed), drinking coffee, tea, colas or red wine, and eating pigmented foods such as cherries and blueberries
- Accumulation of plaque and tartar deposits
- Ingesting too much fluoride (more than 2 parts fluoride per million parts water) when teeth are forming, which gives teeth a "mottled" look
- Treatment with the antibiotic tetracycline during childhood
- Trauma to the teeth that may cause a brown, gray or black color
There are many reasons for whitening your teeth, including:
- The boost to your confidence and self-esteem that comes from a great smile
- A younger appearance
- A special event such as a wedding, job interview or class reunion
- To make a positive first impression on others
- To simply reverse years of everyday staining and yellowing
Before beginning any whitening procedure, be sure to consult with your dentist. Only he or she can evaluate whether you're a suitable candidate for a particular treatment.
Am i a candidate for tooth whitening?
Almost anyone whose permanent teeth have come in can qualify for tooth whitening. Your dentist will be able to assess your oral health and recommend the whitening method that's best for you. Depending on the type and severity of the staining, he or she may suggest one or more of the following treatments:
- A professional cleaning to remove external staining caused by food and tobacco
- Use of a whitening toothpaste to help remove surface stains between dental visits
- For extra results, use of a convenient, affordable whitening gel or whitening strips
- Bleaching (in-office or at-home) for more stubborn stains or yellowing
- Veneers or bonding to fix irregular or damaged teeth or to achieve specific results
Ask your dentist which whitening technique is best for you.
- Teeth that are yellow respond best to bleaching. Brown or gray teeth, or teeth striped or mottled from tetracycline or too much fluoride, may not whiten evenly when bleached.
- People with periodontal disease or particularly sensitive teeth may want to avoid chemical whitening techniques that can irritate tender gums.
- Bleaching is not recommended if you have tooth-colored fillings, crowns, caps or bonding in your front teeth-the bleach will not change the color of these materials, making them stand out in your newly whitened smile. You may want to investigate other options, like veneers or bonding with your dentist.
- In some cases involving serious tooth or jaw problems, a crown or cap recommended to correct orthodontic problems may also result in a whiter and more appealing smile.
How does tooth whitening work?
There are many ways to whiten your teeth-from whitening toothpastes and other products that can remove many surface stains and can produce dramatic results.
All whitening techniques work in one of two ways:
- Bleaching procedures change your natural tooth color, usually anywhere from five to seven shades brighter. In-office (chairside) whitening and at-home (tray) whitening both rely on bleaching. Bleaches contain an active ingredient, most often carbamide peroxide or hydrogen peroxide in concentrations of 10-22%, which helps remove both deep and surface stains. There are significant cost differences between different bleaching procedures:
- A light-activated whitening session in a dentist's office, sometimes called chairside bleaching, can be very expensive and result in instantly and often dramatically whiter teeth. However, after a year or so of eating and drinking normally (coffee, tea, soft drinks), your teeth become slightly discolored again and develop new stains.
- A custom mouthpiece created by your dentist for in-home bleaching can typically be worn several hours a day or overnight for two weeks. When you notice new staining, you just wear the mouthpiece again for a night or two to take the stains off.
- Over-the-counter products for whitening teeth (those found in a drugstore) include boil and bite tray application, whitening gels applied with a brush, and whitening strips.
- Non-bleaching procedures work by physical and/or chemical action to help remove surface stains. All toothpastes rely on mild abrasion to remove surface stains between dental visits. Whitening toothpastes have special chemical or polishing agents that provide additional stain removal. A professional cleaning by a dentist or hygienist also uses abrasion and polishing to remove most external staining caused by food and tobacco.
Everyone responds differently to different whitening procedures. Some people respond well to whitening toothpastes, while people with gray teeth or other serious discoloration may require porcelain veneers or bonding (discussed elsewhere in this section) to achieve the smiles they've always wanted. Only your dentist or hygienist can determine what's right for you.
How safe is tooth whitening?
Over a decade of research has proven bleaching and other whitening methods to be both safe and effective. Several products in the market today have shown no adverse effects on teeth or gums in substantial clinical and laboratory testing. Be sure to look for clinically proven products, follow directions and consult with your dental professional.
In the past, the higher bleach concentrations used in-office treatment resulted in more sensitivity. Today, however, bleaching gels are well buffered, making sensitivity less of an issue. Sensitivity may occur in people after whitening procedures, particularly when they eat hot or cold foods, but usually disappears after 48 hours and stops completely when treatment is stopped.
If you do experience sensitivity, there are several ways you can help eliminate it:
- If using a tray applicator, wear the tray for a shorter period
- Brush with a toothpaste made for sensitive teeth that contains potassium nitrate to help soothe tooth nerve ending
- Ask your dentist or pharmacist for a product with fluoride, which helps re-mineralize your teeth. Brush-on or wear in your trays four minutes prior to and after whitening your teeth
- Stop whitening your teeth for several days to allow you teeth to adapt to the whitening process. Within 24 hours, the sensitivity will cease. The longer you whiten your teeth, the less sensitivity you will experience
In a few cases, your dentist may discourage dental bleaching:
- If you have gum disease, teeth with worn enamel, cavities or particularly sensitive teeth
- If you're pregnant or breast-feeding
- If you have tooth-colored crowns, caps or other dental work in your front teeth, which can't be bleached
How Do I Maintain My Newly Whitened Smile?
Over time, exposure to foods, drinks (especially coffee, tea, colas and red wine) and tobacco will gradually darken your newly whitened teeth. But there are steps you can take to maintain your pearly white smile. Compared to the time and/or money required to whiten teeth, it takes only a small effort to keep them looking their brightest.
Here are some tips for maintaining your newly whitened teeth:
- Use a whitening toothpaste to remove surface stains and prevent yellowing
- Brush or rinse immediately after consuming stain-causing beverages or foods
- Use a straw to drink beverages that stain, such as coffee, tea, colas and red wine
- Wear a bright shade of lipstick-blue or pink based. It will make your teeth appear whiter. Avoid orange or brown shades
Check whether you need a touch up. Depending upon the whitening method you used, you may need a touch up in six months or after a year or two. If you smoke or drink a lot of coffee, you may need a touch up more often.