A nice, bright smile is not only attractive, it projects warmth and confidence. Over time, teeth can go from white to not-so-bright for a number of reasons. Let's look at what affects tooth colour and ways of tooth whitening to give us that whiter smile that everyone loves.
What affects tooth colour?
- Age: Enamel covers the outer parts of teeth. Below the enamel is a softer, yellowish tooth layer known as dentin. With time, the inner dentin becomes thicker and outer enamel can become thinner which causes more of the yellowish colour of the dentin to show through. This is referred to as "intrinisic tooth stain", meaning the darker colour comes from within the tooth.
- Food and Drink: Coffee, tea, red wine and other foods and drinks have intense colour pigments called chromogens that attach to the outer tooth enamel and result in "extrinsic tooth stains", meaning stains on the outer surface of the tooth.
- Tobacco Use: Nicotine and tar are two chemicals found in tobacco that create stubborn stains. Nicotine turns into a yellowish surface-staining substance when it is mixed with oxygen. Tar is naturally dark.
- Poor Oral Hygiene: Skipping brushing or flossing results in teeth coated with sticky plaque (oral biofilm) that food stains love to hang on to.
- Tooth Trauma: A blow to the mouth can eventually cause your tooth to change colour. Teeth react to injuries by having the yellowish dentin of the tooth become thicker so it's more noticable to the eye.
- Medications: A side effect of some medications is possible tooth darkening. Young children who are exposed to antibiotics like tetracycline when their teeth are forming (either in the womb or as a baby) may have discolouration of their adult teeth later in life.
- Genetics: Some people's teeth have a more yellowish hue from the start. Generally, these teeth are somewhat stronger and less susceptible to the mouth acids that cause tooth decay.
- Skin Tone and Make-up: People with darker skin or who use dark makeup will look like they have brighter teeth. A nice bright lipstick always makes the teeth look great!
- Tooth position: Sometimes lower teeth appear somewhat darker because they are in the shadow of the upper teeth.
How does tooth whitening work?
Whitening products contain one of two tooth bleaches (hydrogen peroxide or carbamide peroxide). Bleaches act by simply breaking stains into smaller pieces, which makes the colour less concentrated and your teeth appear brighter.
View this American Dental Association video to learn more about Tooth Whitening:
Can all teeth be whitened?
No. Yellow teeth tend to bleach well but teeth with gray tones may not bleach at all. Whitening will not be effective if your tooth discolouration is caused by medications or tooth injury. It also won't work on dental crowns (caps) veneers or fillings. For the nicest look after whitening, it's important that tooth colours blend well. After whitening, older discoloured fillings may need to be replaced to match the colour of newly bleached teeth. Sometimes it's hard to predict how it will turn out and the colours may blend better than expected.
Is tooth whitening harmful?
- Some people experience mild, temporary tooth sensitivity when whitening their teeth. The sensation is sometimes described as though the teeth are "on edge". The daily use of a toothpaste indicated to reduce tooth sensitivity for two weeks prior to whitening can help to minimize this possible effect.
- To avoid gum irritation after inserting bleaching trays, simply use a tissue or soft cloth to wipe away any excess bleaching gel that may be on the gums.
- Overuse or misuse of whiteners can damage tooth enamel or gums. Health Canada says that clinical studies show that home tooth-whitening products are not harmful when used as directed. Your Lorne Park Dental dentists and team will give you all the information you'll need to do it right!
Over-the-counter whitening products:
- All toothpastes help remove surface stain through the action of mild abrasives that scrub teeth. Picking a toothpaste with hydrogen peroxide can help by breaking down stains and reducing any yellowing effects. Examples are: Colgate Optic White and Crest HD or Crest 3D White
- Some mouthrinses now contain hydrogen peroxide too.
- Whitening chewing gums have added abrasives and/or other ingredients that make superficial stains easier to rub off while chewing the gum. They do not change the internal colour of teeth.
- Crest 3D White Strips and similar OTC tooth whitening products can be effective for some people. Based on our experience, we will recommend the whitening product that we think will work best for you.
At-home bleaching trays:
At Lorne Park Dental we've seen the nicest and longest lasting results when our patients have used at-home bleaching trays.
1. Custom bleaching trays: Impressions or molds of the teeth are needed. We make the bleaching trays to custom fit your teeth. You take them home, syringe the bleaching gel into the tray as directed and wear the trays for at least 1 to 2 hrs. or sometimes over night. This is done each day for up to two weeks on average.
2. Generic-sized bleaching trays: Comfortable, 'one size fits all', pre-loaded bleaching trays are available which contain a faster-acting bleach and are worn for 20 mins. per daily application until the desired results are reached.
All about Opalescence brand tooth whitening products in this video:
Opalesescence Go - Step-by-Step Instructions:
Whitening teeth for a special occasion:
At first, teeth may have a starker white appearance to them. A couple of weeks or so after bleaching they settle into a more natural white colour. For this reason, finish bleaching two weeks or so before special events where photos will be taken.
How long do tooth whitening results last?
Everyone's teeth yellow naturally with time regardless of what we eat or drink. How quickly this happens varies from person to person. Depending on how teeth are whitened, we find that they usually don't go back to their original shade of yellowness prior to bleaching. They may however, start to look a touch dull or somewhat yellow again. Re-bleaching for a shorter period of time will give teeth a boost to bring back that brighter smile.
