I used to brush with a little force on my hand until i've learnt and notice about my dentins,enamel and how to brush.
i don`t know if it is abnormal , or maybe it is within my genes.
but its thin,transparent and allow my dentin to be shown like a smaller square(yellow) inside my enamel.
But anyhow, i would go and consult a dentist. Thanks for advice.
you should see a good cosmetic dentist to evaluate your teeth from a cosmetic perspective. there are indeed ways to make them whiter--- from bleaching to veneers to crowns, but there are many things that weigh in on what's best-- there are also many reasons why enamel is "thin"-- the dentist needs to examine you to give you the proper answers to your questions.
I would be concerned why the enamel is wearing that much for someone your age. I do not know if your are grinding or bruxing and I would try to alleviate the cause first.The whitening can make the dentin sensitive. I think you need to find out what is causing the abnormal wear.