Hi, let me share my smoking story. When I was in fifth grade I started smoking. When I get into my teenage, I smoked every day. I was so addicted to it. I couldn't live a single day without smoking. During my college days, I used to smoke at least 4 packs a day. My friend Ella told me to stop it. But I couldn't resist it. She took me to the anti-smoking programs. During my withdrawal days, Ella supported me. I stopped my smoking habit. Recently I noticed stains on my teeth. My teeth were yellowish due to my tobacco usage. I tried to keep my mouth closed while smiling at others. I was feeling ashamed when I talk to others. I'm planning to undergo teeth whitening procedure from a cosmetic dentistry in Whitby. Does the tooth whitening cause permanent tooth sensitivity? How long does the teeth whitening last? Kindly share your views and suggestions.