Is laser teeth whitening better at making the teeth white as compared to the trays the dentists give?

I had the trays once but they didnt make the entire tooth white, as if the product didnt cover the entire tooth, it wasnt uniform. will the laser (i think its laser), the one time whitening be better at making the teeth all white?
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I always tend to stay away from such expensive methods and some Dentists say that such methods can harm you in a long run. If you are really looking for teeth whitening, normal toothpaste probably isn't enough just by itself. I suggest doing what this mom did, http://laurateethwhiteningblog.blogspot.com/
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