Whiter Brighter Lighter Smile

Everyone loves a happy smile. 

It is however important to remember a happy smile is a healthy smile and  is made of more than the colour of your teeth. I do love to see someone with a healthy natural smile, but indeed sometimes there is a place to think of brightening the colour of your teeth.  What should you think about and what can you do?

First let’s think about what determines the colour of your teeth. 

The colour of your teeth is determined by the amount of light that is absorbed by your teeth and therefore the amount of light that is reflected to the observer. The less colour absorbed, the more light reflected.

The basic colour of your teeth is determined by the “intrinsic” factors. These are the internal physical characteristics of YOUR teeth.

This is determined by more than just the pigmentation of your tooth, this is influence by:

* The colour and thickness of the enamel (the outer shell) you are born with. 

* The dentine (the inner layer under the enamel) is thin when you are born and will continue to thicken as you grow older

* The thickness of both layers, the surface texture of the enamel, the stains absorbed by the tooth from food and drink, will all affect the intensity of the light absorbed and reflected and therefore the colour that you see.

When you are young, the enamel is naturally at its thickest, it has a surface texture that reflects the light and the inner layer of the tooth, the dentine is darker. If the enamel thins with time, wear and tear and acid erosion, this lets the darker dentine shine through. The dentine get thicker with age / time and it therefore gets darker and adversely shines through the thinner enamel. 

This is why parent’s teeth are generally darker than their children’s. 

The “extrinsic” factors are all the external forces that can change the “intrinsic” colour of your teeth. Wear, thinning of enamel by acid erosion, foods and drinks that discolour the teeth.

What can you do about it? 

* Be aware of factors that thin your enamel. Excess acidic in food and drink is probably the major factor in erosion. The enamel gets thinner, and the surface texture becomes “polished”. An older patient will always have smoother teeth that reflect less light and look darker.

* Be aware that some foods and drinks will discolour your teeth more than others. Tea, coffee, red wine, smoking.

* Be aware that poor toothbrushing and oral hygiene will allow a build up of protein and plaque on your teeth. This will absorb the above and contibute to adverse colour change. (See your hygienist 6 monthly to reduce this build up)

What should you think of if you actively want to brighten the colour of your smile?

There are a few options but first let’s look at how “Whitening” works:

The active ingredient in any bleaching product is hydrogen peroxide. This reacts with the darker pigments and stains and “oxidises” these. The hydrogen peroxide is usually in the form of a gel that is applied to the surface of the enamel. This is sometimes applied as Carbamide Peroxide which releases the hydrogen peroxide. 

The concentration of the hydrogen peroxide is the first critical factor.

The higher the concentration, the more the effect. In Europe the maximum recommended percentage recommendable by a dentist is 6%. 

Tooth Whitening: What We Now Know

The maximum concentration in whitening strips, mouthwash or toothpaste is 60 times less at 0.1%.

The second major factor is the duration or time that the hydrogen peroxide gel is applied for. The greatest effect is attained in the first hour, then the second hour. There is little bonus to applying the gel overnight.

You should also be aware of a few things.

The roots, or dentine of the teeth, will not change colour. 

Excessive concentration or duration of application can cause sensitivity. If the dentine (root structure) of the teeth is exposed the sensitivity will be more of a problem.

Hydrogen peroxide will not work through bacteria or plaque.

Best practice is to ask a dentist before you start whitening your teeth. The dentist will advise you if you are suitable and discuss the options and any concerns.

We advise anyone under 18 should not whiten their teeth.

They will be looking to see if you have any gum disease or plaque accumulation which should be treated before you start. 

They will check if you have any fillings or crowns, which will not change colour when you whiten the other teeth.

They will look for exposed roots that may cause sensitivity if you proceed.

They will look for any cavities that need to be dealt with first

They will discuss any options that might be a better solution to meet your expectations.

The nitty gritty. What choices or methods can you consider?

Professional Home Whitening. 6% hydrogen peroxide can be recommended / prescribed by your dentist if you are suitable. The dentist will provide a customised vacuum formed soft tray that fits snugly to your teeth. The 6 % gel is put into the tray and the tray worn for two hours. (Brush your teeth first). 

The dentist can also do an “IN-Office” whitening procedure. This uses the same 6% gel that is applied to the teeth and the whitening action is accelerated by activating or heating the gel for upto 60 minutes. This is often referred to Laser Whitening or Zoom Treatment. Note that this will accelerate the action, but I would still recommend you also use the Home whitening trays to maximise and maintain the result of the initial “accelerator” appointment. This In-Office procedure will give you a quicker effect but will add to the cost.

Whitening strips:  These are increasingly popular as you can buy them over the counter. Please note though that these are by law less then 0.1% active hydrogen peroxide. This is 60 times less concentrated than the professional options above and will subsequently take a lot longer to acheive the same effect.

Whitening toothpastes / mouthwashes: These by law have to be less than 0.1% active hydrogen peroxide. The time that the toothpaste is in contact with your teeth is minimal.

My recommendation would always to be first ask your dentist is it ok to whiten your teeth. See the hygienist if recommended, to ensure there is no exposed root surfaces and or fillings to consider, the teeth are clean, and the gums are healthy. 

My first choice for results and price over all the 40 years we have been doing this:

I prefer the Home Bleaching trays with the 6% active hydrogen peroxide available from your dentist. These trays should be worn 2 hours a day. 

If in the unlikely event that you are getting sensitivity, go back to your dentist and check all is ok, they will probably recommend you wear the trays every other day to reduce the speed of treatment.

Once you have achieved whatever the result you can or you are happy with, you can still use the trays once a month to maintain the result you have achieved. 

This is the most effective and cost-effective way to brighten your smile.

Note that depending on your diet and “extrinsic” (external) factors your teeth will always have a tendance to darken with time. You will need to re-treat to maintain whatever result you have achieved.