“A number of years I broke a tooth and had it replaced from halfway down. I am now considering having my teeth whitened and wondered what happens with that tooth.
I do not want to have tooth bleaching done and then have that part that was replaced be a completely different colour. Can it all be the same colour as the real teeth around it with a tooth whitening treatment?”
– Question from Jane of Zillmere, Brisbane
Dr David Kerr replies:
People often don’t notice their teeth getting darker
Quite often teeth will darken at such a slow rate that most people simply won’t notice that their teeth have become more yellow or the colours become darker and more intense over time. Often it is someone else that will notice it on you before you pick it up yourself.
It’s like balding. You don’t notice that you are gradually loosing your hair until you meet up with an old (and honest) friend or compare yourself to an old photo. The same can be said with how your teeth change colour over the years.
If you have had a crown or a veneer from many years ago then this gradual darkening change in your teeth may be more noticeable next to either the composite or porcelain that will generally remain the same colour.
If you have used porcelain for your dental work the colour will pretty much be the same as the day you had it done. This incredibly hardy material comes out of the kiln at 960 °C and in most cases has been toned to match the rest of your teeth. Veneers are also often toned within the veneer to darken slightly from bottom to top – this gives them a more natural look and they fit in with your real teeth more seamlessly.
Things to check before doing veneers or crowns
We don’t want to put the cart before the horse so when people are considering veneers or having crowns we take a moment to check in with them about the colour of their teeth.
We check if they are happy with the colour of their teeth and if they have any plans or desires to change or whiten their teeth in the next 5-10 years.
If the answer is YES then we highly recommend a teeth whitening treatment before having veneers or crowns. It is best for patients to get their teeth to their desired whiteness and then colour match your veneers or crowns to that.
Whitening will not damage these past treatments
There is no real down side to having dental tooth whitening treatments in terms of damaging past dental work. It is more of a cosmetic thing. As mentioned above porcelain (and composite resin) are extremely hardy materials that can withstand the tooth whitening process.
Considerations if you are whitening and then doing other dental treatments
The dental whitening process will dehydrate the tooth so there is a period you need to wait between when you finish whitening teeth and then doing any other treatment such as fillings or gluing crowns on teeth.
Firstly, we like to let the colour of the teeth stabilise and the hydration to normalise as it is only then that we will get a good idea of the colour that the patients teeth are in order to colour match the veneer or crown. This is generally a period of 10 days – 2 weeks.
We also wait this time period to ensure the best adhesion or bond between the newly coloured tooth and the veneer or crown. If the tooth is still dehydrated then this adhesion can be reduced if a procedure is done prematurely.
A final note about veneers and whitening – make sure yours are colourised to be natural
When you are whitening teeth, be sure to consider that different parts of the tooth have different intensities of colours, this is just an anatomical thing. The bit of tooth up near the gum is never as white as the edge that does the chewing. The chewing part of the tooth is generally thinner and the colour saturation of the tooth is less at this end.
Some people think that their teeth after whitening or veneers will come out in a uniformly white colour from top to bottom. Whereas what will happen is that they will actually maintain the normal proportions of colour and grading from top to bottom of the tooth. This is a more natural result otherwise you would be left with a result that looks like … dentures!
If you have any other questions about Dental tooth whitening then visit our Tooth Whitening Frequently Asked Questions (FAQs) >