Monthly Archives: September 2013

Tooth whitening at Northway Dental Practice

Here at Northway Dental Practice we’ve noticed that wanting teeth whitened has become much more frequently requested over the last 10-15 years. Partly due to the rise of celebrity culture and partly due to improved living standards and expectations/aspirations.

We can broadly divide the types of patient who come to us asking for whitening into two groups. 1) Young patients who often want super-white teeth, often these patients have normal (not very dark) coloured teeth to begin with. 2) Older patients who’s teeth have darkened over time and who want them to look whiter as they did when they were younger. Often these patients do have quite dark teeth.

So what colour should teeth be? 

Naturally most teeth (around 95%) have a yellowish colour. The teeth are made of enamel on the outside which is translucent/white colour, and dentine inside which is usually yellowish. The colour we see is a combination of these two colours and the hue of the light which is shining through the teeth. A smaller number of people perhaps 5% have light grey teeth or other colours such as light brown. Some people have teeth with bands or spots of unusual colour caused by a variety of disorders of tooth development.

Do teeth get darker as we get older?

Yes. Three processes cause this to happen. Enamel thins over time and therefore, since it is the white component of the tooth, the dentine shows through more – which is the usually yellower or darker component. So as your teeth wear, which is normal as we age, they appear darker. The second process involves stains from foods and drinks, which usually remain on the surface of the teeth, but gradually over many years permeate into the enamel and dentine, causing the colour to change – we call this intrinsic staining. The third process is that fillings can leak causing staining to get into the teeth, or just look dark themselves as they are metallic coloured and this shines through the tooth making it look dark or grey.

What can we do about it – why not just use whitening toothpaste?

Whitening toothpaste is, in my opinion, a little misunderstood. What it should be called is extra-cleansing toothpaste. It is designed to scrub the surface of the tooth harder to remove stains. In doing so the teeth should look a little brighter. This is useful but it is not quite the same as tooth whitening since it does not change the actual underlying colour of the teeth it just removes stains. If your teeth were yellow AND stained before using whitening toothpaste they will still be yellow afterwards but no longer stained. Some people suggest that using these products too much can lead to more tooth wear, which in the long term is harmful. Our advice would be to use whitening toothpastes occasionally but not daily.

What does professional tooth whitening do?

Basically it bleaches the teeth. In the same way you can bleach your hair or your clothes to remove stains or whiten the colour, you can do the same thing to the teeth. The process though is a little different since teeth are not made of fibres like hair and clothes are – they are made of hard mineral much more like stone or rock. The bleach used is NOT household bleach, but a special formula designed for teeth. Never use anything on your teeth that is not designed for teeth and never use anything on teeth unless it is supplied by a reputable person who you trust and can go back to in the event of problems, the best person is your dentist.

The professional whitening process involves measuring your tooth colour and photographing your teeth, then making some trays to put the bleach into, providing you with the trays and whitening formula and showing you how to use the system, you doing the treatment at home over (usually) 1-2 weeks, then a review appointment to see how it all went. We do not do “one-hour whitening” or “laser whitening” all of which are methods to make marketing the treatment easier, not of achieving a better result. We have carefully considered the system we use as it is gentle, easy to control and kind to the teeth.

How white will they go?

Usually over 1-2 weeks the shade improves considerably but the teeth remain a natural white. If you carry on the treatment for a longer period than the usual 1-2 weeks lets say for 4-6 weeks you will normally achieve a very white shade indeed. You can carry on as long as you wish the decision when to stop is yours.

Is it safe?

Yes. Provided you use the right whitening formula such as the system we use and use it as directed, there has never been any harm caused to the teeth or gums. Since teeth are not like cloth or hair they do not get damaged by the bleach, they are much tougher to begin with.

Are there any drawbacks?

There are some considerations. We need to carefully assess the teeth before treatment. If you have white fillings or white crowns/bridges/dentures they will not change colour. This might make them look too dark, if so do you will need to plan to change these items after whitening. This makes the process quite a bit more complicated.

Sensitivity is one complication that sometimes occurs and we will not easily be able to predict. Some people will experience sensitive teeth temporarily during the treatment (it does resolve afterwards). For some it will be quite noticeable for others hardly anything at all. Those who get most sensitivity will often whiten fastest so it is not always a bad thing.

Cost is also a factor – whitening treatments can be expensive since there is a lot of preparation involved in doing the treatment properly with predictable results. However the ongoing cost of maintaining the white colour is low as you will already have the trays, and be experienced with using them. You might need a refill pack of whitening formula.

How long does it last?

This is a good question and the answer is often not the one people expect. Unfortunately it cannot be permanent as the processes which darken the teeth (wear & tear/fillings/intrinsic staining) are going to continue after treatment finishes. So you will notice the colour gradually fading, over perhaps 1-2 years. At this point you can re-whiten the teeth using just 1-3 nights treatment; so maintaining the colour is easy and simple. Some people go for a one night per month method as a way to keep the colour white on an ongoing basis. Once the initial treatment is complete we leave you to maintain things as you see fit, with help and support if you require it,  and we can supply refills of the whitening formula at very reasonable prices.

Why shouldn’t I use kits from the internet/beauticians/market stalls?

The simple answer here is that the kits can contain harmful chemicals or ineffective chemicals and they are often sold very cheaply and therefore produced very cheaply also. The people undertaking the treatments can have little or no training, and are unable to assess the health of your mouth (you need to be a qualified, registered dentist to do this). Taking impressions is considered to be the practice of dentistry and it is illegal to take an impression for someone unless you are a dentist or properly trained dental hygienist or in some cases, dental nurse. The EU now specify that whitening gels of effective strengths are only to be supplied by dentists to patients and that dental supervision must be in place when teeth are whitened.

If you want to know more about tooth whitening please book in to see us. We will very happily assess your mouth and if appropriate begin the process. See our website for more details.