I've been a heavy coffee drinker and smoker for 40 years. I do take care of my teeth but there were some brownish looking areas inbetween teeth and a general "not so white" look. Well I finally quit smoking a month ago and decided it was time to clean up my act even further. Had an older Electric toothbrush that was finally failing. Did not want to spend a lot of money to "try" out something else so I bought this. WOW! After my first brushing with this it felt as if I had got a cleaning at the dentist. Long story short... brushing each day with this and using the little crevice brush head they include, 3 weeks later there is an ENORMOUS positive change in my teeth. After seeing my results, my wife, daughter and son-in-law all bought one for themselves.