Myth #1: Whitening Toothpastes and Mouthwashes Whiten My Teeth
Partially True. Toothpastes and mouthwashes labeled as "whiteners" only remove external stains. If you smoke or drink coffee, tea, or red wine then it will work well but the internal yellow color of your teeth likely will be unchanged.
We did find a single study by the ADA though that postulates using whitening mouthwash daily after 12 weeks can have the same results that whitening gels have after 2 weeks. We live in such a microwave society ("I need it now") that it makes sense just to whiten with trays up to 2 weeks.
Myth #2: Whitening Products Ruin My Enamel
The quick answer is no. What ruins teeth are neglect, decay, dry mouth, acids sitting on teeth, etc. Most whitening studies have been done on bleaching gels (10% carbamide peroxide sold in dental offices) and the ADA has never found any significant or long-term risks from using professional at-home bleaching gels if used as prescribed. This relates to the nerves, inner dentin layer of the tooth, and the outside enamel.
We typically see teeth get 2 shades whiter after 5-14 days of consistent whitening. Depending on the gel percentage, you only need to wear trays anywhere between 30 minutes to 8 hours.
Myth #3: My Teeth Stay White Forever After Whitening
Here is a comprehensive list of products that stay pristine forever...
...
That's right, everything breaks down over time: your car, kitchen appliances, jewelry, yard, spouse, and teeth color--even after whitening.
While the effects of whitening teeth with OTC products like Crest Whitening Strips last weeks to months, whitening gels sold at dental offices usually last months to years.
2 weeks straight is usually the most time needed to get an obvious whiter shade. To keep that ideal shade through the years, do touch ups every 6 months for 1-3 days--that's it. If you cut back on coffee, tea, red wine, and smoking that will drastically help keep your whiter shade longer.
Myth #4: My Teeth Can Get Toilet Bowl White if I Just Constantly Whiten
Unfortunately this is a myth. There are some teeth that will never have that movie star bling. People have about 4 different family colors of teeth (labeled A through D) and your teeth can only go as white within that family. If you are an A4 you can only go as white as an A1. If you're a B4 you can only get to a B1. A natural healthy white is A2 (2nd tooth on the left) for reference sake. Anything whiter than A1 or B1 appears unnatural usually.
Myth #5: Whitening with Blue Lights is Most Effective
Though you can find studies defending whitening with blue lights, the majority of recognized scientific research show using bleaching lights dehydrate your teeth and give you the temporary façade that they're whiter. This technique does whiten your teeth more rapidly but yellow faster over time too.
Solution: The most effective whitening with longest results is actually to use a lower percentage of whitening (i.e. 10% hydrogen peroxide or 10% carbamide peroxide--we sell both.) that are dispensed at our office in take-home gels.