Bleaching

When we talk of bleaching we are talking about changing the intrinsic colour of a tooth. Virtually all dark or discoloured teeth can be bleached or lightened to some extent. Bleaching works best for yellow, brown or orange stains and not as well for grey stains. Bleaching  is a different  process from cleaning teeth, were you are removing extrinsic staining on the surface of the teeth.

 

Bleaching  doesn’t work if the discoloration is due to decay, is on the surface of the tooth or is due to stained fillings.  If one tooth is darker than the rest then bleaching using trays is not normally indicated. Bleaching doesn’t really work that well if your teeth are already fairly light and white.  There is no room to move.

 

The way that I do it is to take an impression of the teeth and make a small tray that snugly fits the teeth.  The bleaching gel is then placed in the tray. This tray is then worn at night while asleep.  It can alternatively be worn for a few hours during the day but this is not as efficacious.

 

Within a few days there will be a noticeable change in colour. Initially the colour change may appear uneven.  This unevenness normally goes as you continue bleaching. The remaining change will be more gradual. 2/3 weeks is normally long enough. If you miss a day don’t worry. It doesn’t mean that you have to go back to the beginning. It means it will take day longer to get were you want to go.

 

When you stop bleaching the teeth will be whiter than the final colour. There will be an immediate rebounding or relapse.  The teeth will stabilise in about a week. After you finish bleaching keep the trays and the bleach. The teeth will slowly and gradually begin to darken. After six months you may need to bleach the teeth for a couple of days.  After a year maybe a week.  This should keep the teeth reasonable stable.

 

The gel is safe.  It contains a peroxide which releases oxygen.  This is not similar in any way to household bleach which releases chlorine.

 

Bleaching can cause tooth sensitivity. To help prevent this sensitivity it is best to avoid acidic liquids (soft drinks, vinegar and wine) whilst bleaching teeth.

 

Bleaching is not indicated if ulcers are present in the mouth.  Any filling, crown or veneer will not lighten when the teeth are bleached.  This can mean that post-bleaching the fillings will appear darker and be more noticeable. They may have to be redone or replaced. Over bleaching can change the opacity of the teeth and actually make them look worse.

 

There are a variety of other products available at the supermarket that are promoted for bleaching teeth.  In general the claims on the packet are very optimist. There are bleaching toothpastes, strips that you stick on the teeth or gels that you paint onto the teeth. The main harm that most of them do is emotional let down when expectations are not realised. Most of the products don’t keep a high enough concentration of peroxide in contact with the teeth for long enough.