will teeth whitening work on discoloured teeth due to root canal treatment .

HI there - as a dentist I get asked this question quite a lot! We can carry out a procedure called 'Internal Bleaching' whereby a small hole is made in the tooth and bleach is inserted internally. This will effectively whiten and brighten teeth that are otherwise unresponsive to whitening procedures. As always make sure you speak to a dentist about your concerns to make sure this treatment is the best one for you. Please feel free to email me on reinvent@traceybell.co.uk with all your dental enquiries big and small! See my youtube channel to see our dentists at work! Keep smiling!

no you have to do internal bleaching,so the dentist put bleach inside the tooth to lighten it up, the other teeth you can whiten with gels or strips try
You can buy any strength gel nite white 10 percent 10% is the weakest and you buy the do it yourself bleach trays from them at http://www.crestwhitestripsnow.co.uk and comes with full instructions for you to do all the whitening at home using carbamide peroxide or hydrogen peroxide which is what dentist professionals use and charge 4 times more! http://www.crestwhitestripsnow.co.uk does free shipping and they also carry a full line of crest products, toothpastes, zoom whitening , pola night and pola day products, cheapest online source you will find with the top whitening gels and best tooth whitening products made and used by the top dentist
Source(s):
http://www.crestwhitestripsnow.co.uk

As a rule we state as long as they are your own natural teeth we can whiten them.