Don't know what to do!!

[Jamie b]

To anyone who can help

When i was 16 i had perfectly straight teeth after having a brace for 3 years, then 6 months later i had the front 2 knocked out in an accident.I had them both replaced with high quality crowns from south africa, but now 7 years later all my teeth on show are turning yellow including the crowns which are a darker shade.
i am now very self concious about smiling so wanted to start looking for some options for example venners and two replacement crowns on top teeth and a highly effective whitening procedure on bottom. i havnt really alot of money but am willing to spend in the right areas.. please help

Jamie

[prosman]

you should get this checked out ASAP as colour change under the crowns could be a sign that the teeth are not entirely well