Karl Bishop by wanghonghx


									  KARL BISHOP

 consultant in restorative dentistry

                               Tooth Whitening

                      Tooth whitening is the removal of teeth stains by bleaching to
                      whiten the teeth. There has been much debate about its legality
                      but the dental profession considers this a more appropriate
                      option in situations where only colour changes are necessary and
                      the teeth are otherwise sound. The legal issue surrounds
                      whether the bleaching material is considered a cosmetic or
                      medical agent. Basically, the bleaching agents which have an
                      effective concentration cannot be sold as a tooth whitening agent
                      but the material itself is legal.

                      What are the different options for tooth whitening ?
                                    • Dentist-monitored home bleaching techniques
                                      involve the use of a gel and tray system that
                                      looks like a mouth guard.

                                         • In-surgery techniques utilise a higher
                                           concentration of bleaching agent and a light
                                           or laser-activated unit for 'power'

How does the home technique work ?
The essence of this technique is that you bleach your teeth at home using
a tooth whitening (bleaching) gel, which is held next to the teeth by
special bleaching trays.

Initially moulds of your teeth are taken so that the special bleaching
trays can be made, and you are then shown by your dentist how to apply
the tooth whitening gel to the trays.

You will then take the gel and the trays home and use them for
approximately two weeks (if your teeth are heavily stained you may need to use the
treatment for longer - up to six months). It is best to use the gel and trays overnight,
in other words sleeping with the trays in. If this is not possible, the system should be
used for a minimum of 2-3 hours every evening with the gel being replenished every 2-3

Will tooth whitening damage my teeth ?
No. The majority of the literature and research indicate that dentist-monitored home
tooth whitening techniques and in-surgery system are effective and safe ways to lighten
discoloured teeth.
What types of stains are best suited to tooth whitening?
All types of stains are suitable for tooth whitening, although darker teeth may take
longer to bleach and brown discoloration is more responsive than grey. The initial colour
of the affected teeth seems to determine the success or failure of the technique. It
appears that the lighter the stain the easier it is to bleach. In order of easiest to
bleach to most difficult: yellow, light grey, light brown, dark yellow, dark brown, grey or
black. It has also been suggested that, because they are more porous, younger teeth
would be easier to bleach than older ones. Tooth colour is primarily determined by
                    dentine and can be changed by bleaching treatments.

                    What is the effect on existing crowns and restorations ?
                    The whitener will not affect the colour of existing crowns, veneers,
                    bridges or fillings that you may already have in your mouth. As such
                    they will stand out in your newly whitened smile and as such they
                    may need to be replaced following bleaching.

                    How long does tooth whitening last ?
                     Tooth whitening should last for approximately 18 months to 3 years.
The length of time depends on your eating, drinking and smoking habits: tea, coffee, red
wine and smoking cause teeth to discolour more. At this stage you will need to have a
‘top-up’ of the bleaching procedure.

Are there any people for whom tooth whitening is not a good idea ?
Virtually everyone wanting to lighten their teeth can benefit from tooth whitening.
However your dentist will determine your suitability for the different techniques.
People who have a history of joint problems, extreme sensitivity to hot and cold food or
drink, and people with numerous fracture lines in their teeth may not be good
candidates for tooth whitening. If you have a gum disease, it should be treated before
any tooth whitening procedures are carried out. Patients who are pregnant or
breastfeeding should be excluded from bleaching procedures because there is lack of
information concerning possible effects on the pregnancy.

Are there any side effects to tooth bleaching?
In some studies, patients have experienced uncomfortable short-term side effects
when having teeth bleached. Hydrogen peroxide can increase temperature sensitivity in
the teeth, particularly at higher concentrations, and nightguards often cause gum
irritation. These can be minimised by increasing your exposure to the agent over a few
days and by using a fluoride mouthrinse.

Overzealous use of over-the-counter home bleaching products can wear away tooth
enamel, especially with solutions that contain acid. Therefore, bleaching is a procedure
best done under the care of an oral health care professional. Still, the general health
risks of bleaching systems are minimal as far as your body is concerned. Applications
are controlled so that you don't swallow hydrogen peroxide
Can individual teeth be bleached ?
Individual or groups of teeth can be bleached as can the inside of teeth when the
discoloration is due to a nerve dying.

What about whitening tooth pastes ?
All toothpastes help remove surface stain through the action of mild abrasives.
"Whitening" toothpastes have special chemical or polishing agents that provide additional
stain removal effectiveness. Unlike bleaches, these products do not alter the intrinsic
colour of teeth.

How can I look after my teeth once they have been whitened?
You can help to keep your teeth white by cutting down on the
amount of food and drink you have that can stain teeth. Don’t
forget, stopping smoking can also help prevent discolouring and

We recommend the following tips to care for your teeth: ·brush
your teeth twice a day with a fluoride toothpaste cut down on
how often you have sugary snacks and drinks · visit your dentist
at least once a year.

Where can I get further information ?
•     http://www.ada.org/public/topics/whitening_faq.asp
•     McCaslin AJ, Haywood VB, Potter BJ et al. Assessing dentin
       colour changes from nightguard vital bleaching. J Am Dent
       Assoc 1999;130:1485-90.
•     http://www.dentalhealth.org.uk/faqs

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