External bleaching affects the tooth surface not its core, as opposed to the internal bleaching. It can be done at home or at the dental office. Whatever type of whitening is chosen, a dental check-up is always required in order to assess the state of the teeth, make a decision of the type of whitening to be used, and all teeth are cleaned from tartar and dental plaque.
Teeth whitening at the dental practice is done in one day. Whitening procedure itself takes about 1-2 hours. Once the patient is prepared and the teeth are cleaned, dental retractors are placed and a special gel is applied on the gums that protects them from the bleaching agent, which is applied to the tooth surfaces.
Using light from a tooth whitening lamp or a laser beam, the bleaching agent is activated and its action begins. It takes 2-3 consecutive applications and activations in order to achieve the desired colour. Then desensitizing therapy with specific drugs is carried out in order to prevent subsequent tooth sensitivity.
An advantage of this method is that bleaching is done in only one day, and all operations are under the control of the dentist.
Disadvantages of this type of bleaching are the high cost and the greater sensitivity of teeth after bleaching.
Teeth whitening at home takes several visits to the dental office. On the first visit, the initial colour of the teeth and the desired colour are determined using a special colour scale. This is followed by impressions of the upper and lower jaw, which serve to develop individual teeth whitening splints. (Recently, whitening systems for home use of ready-made splints have emerged on the market, but they are not recommended for use because the shape of the teeth of each person is unique and the splint cannot fit closely over the teeth, which can lead to leakage of bleach in the mouth and burning of the gums.)
Once the splints are ready, they are fitted in the patient’s mouth on the second visit. A bleaching agent is applied and the dentist explains how much gel and where it should be applied. The time of action of the bleaching gel is different – from 30 minutes to 5-6 hours, depending on the type of system (day or night). Once the patient has mastered the procedure of bleaching with individual splints, dental checks every 3-4 days are carried out in order to determine the effect of bleaching. Reaching the desired result is usually seen in about 10-12 day.
The disadvantages of this method are insignificant: a slower process with low risk of burning the gums in poorly constructed splints or if too much whitening gel is applied.
The advantages of home bleaching are: the splints can be used in future bleaching, the bleaching agents is less damaging to the enamel of the teeth due to the lower concentration, and not least the price is much lower.
A very important feature of external whitening is that crowns and fillings, already in the mouth, do not change colour during bleaching, so replacement with new ones with a suitable colour is necessary.
After bleaching is completed, instructions for maintenance of excellent oral hygiene are provided (for a longer duration of the whitening), and also for the use of special fluorine-containing pastes, which strengthen the structure of the enamel.
Professionally bleached teeth are a guarantee for a shiny and attractive smile that is important for the self-confidence of every person.