Does whitening your teeth remove important enamel?

I would like to whiten my teeth but heard that it removes minerals and enamel from the surface of the tooth leaving more exposed to decay. Has anyone heard this and is it true? Is there any difference between a dentist whitening your teeth and buying light enhanced whiteners and gels via ebay?
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I dont know. I only know is I did once at dentist and she use same products sellling at stores! And, this keep your teeth white for only 6 months or 1 year. Then, you need to do again because is for short time, not forever. And, more you do, more sensitive and hurt your teeth. And, you cannt eat and drink: cofee, chocolate, carrots, curry, blueberry, because r things make your teeth become brown like cigar and you lose your whitening more fast than 1 year because this is strong color food. You cannt drink tea too. You cannt smoke. This things make you lose white effect fast, become yellow teeth and worst: become like you smoke, brown somewhere if you have artificial teeth in white color. I mean if you have cavity and you replace teeth with white color, not the whitenning gel (this part were u had cavity, become brow!). So, make sure if you wanna spend money to lose fast if you keep eating and drinking and smooking what i wrote. Too much green things you cannt eat too because is strong. This way, you only get sensitive teeth! This is bad! p.s.: rubbish, you cannt eat too a large list of strong colors food. My english isnt good I cannt tell you all but more or less is this.
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