I have whitened my teeth twice before at the Dentists with Zoom and Britesmile Laser. Although results are immediate, the process is really painful as teeth sensitivity heightens in accordance to the strength of the treatment. Not to mention both dental procedures I had were pretty costly at around $700 - $1,200. Comparing the price, results and pain to the home teeth whitening kits, I would say the DIY version is a much better option. Upkeep the results with special whitening tootpastes and you are set for a movie-star smile. Here are several Home Teeth Whitening Kits you can try:
CleverWhite kits sold at Watsons and Accendo.com.sg at S$44, is a more traditional type of teeth whitening. A 10 day system has 10 pre-filled trays that you fit into your teeth like retainers and leave on for 30mins. This was how they did it before Zooming your teeth became popular.
GoSmile kits are sold at Sephora and Strawberrynet.com. Their latest kits come with a Smile Whitening Light device, the same thing Dentists use in clinics. Results are good but costs S$420 for a 12 days (24 ampoule) system. Think about holding the device up to your teeth for 30 minutes everyday. Without the light device, a starter kit 10 day system (20 ampoules) that comes with toothpastes costs S$151.
Crest White Strips S$75 for a 20 day system, buy from crestwhitestrip.net. I have tried this before and am very happy with the results, it's the only home kit that claims to be enamel-safe and that is reassuring. Not sure why it isn't sold in Singapore. Using the same logic as old-school teeth whitening kits, only instead of trays you get flexible strips to apply over your teeth.