4 months ago i had my teeth whitened at the dentist but carried on smoking, my teeth have gone yellow again?

I have since stopped smoking and would like to whiten my teeth again. since ive only had it dont recently the stains are surely just superficial so will an over the counter product work to remove these new stains in the last 4 months and restore my teeth to the white they were after the dentist whitened them Thanks for any answers!
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There are toothpastes out there that have gradual whitening capabilities, which won't be as tough on the enamel of your teeth. Remember, with enamel, once it is gone, it is gone. You can't get it back. The use of OTC whitening products can soften and eat away at the natural enamel of your teeth, causing increased sensitivity and actually promoting tooth decay, rather than preventing it. PlusWhite makes a toothpaste for coffee drinkers and smokers whose capabilities are supposed to be rather good. I would try something like that, or like it was mentioned earlier, see your dentist for another treatment, or other options.
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