Teeth Whitening question

[the1ndonly]

So I've been using this teeth whitening pre-brush rinse mouthwash by Listerine. I've noticed my teeth become noticeably whiter. Do you guys think i should continue using this product, cause im guessing once my braces are off the areas where the brackets were wont be as white? What do you guys think.

[Zoso]

I am extremely skeptical that the amount of contact time and the concentration of peroxide (2%) in this stuff would allow for actual bleaching of the teeth to any appreciable extent, so I must wonder how it is affecting this visible whitening you are seeing.

I took a look at the ingredients, and I am a little fearful I may have a possible answer, and it's not a good one. One of the components of this rinse is citric acid, so I find myself wondering about the pH of this preparation. Contact with acids will tend to weaken the enamel, and if you then brush, you run a higher than normal risk of physically brushing away a microlayer of enamel. If it's occasional, it's not a big deal, but if you are causing this every time you brush, the cumulative effect is going to leave you with a very thin, fragile enamel layer on the teeth, or even with dentin exposed. This is why you will have seen so much advice here on these forums about not brushing your teeth soon after consuming acidic drinks. And along similar lines, at least one study has concluded that "it is recommended that low pH mouthrinses should not be considered for long term or continuous use and never as pre-brushing rinses" due to the erosion of the enamel that can result. (The erosive effects of some mouthrinses on enamel A study in situ, The Journal of Clinical Periodontology, 2001 Apr;28(4):319-24) So you can see why I wonder if any whitening you might be seeing with this Listerine pre-brushing rinse could be from simply brushing away the very top, stained, enamel.

All of this said though, and I don't mean to be rude or cause offense here, but are you absolutely certain that it really is improving the colour of your teeth? I've turned up at least two studies that say otherwise - here are their conclusions:

Clinical Trial Comparing Peroxide Whitening Pre-Rinse and Negative Control

While there were no between-group differences in whitening effectiveness, twice daily use of a peroxide alcohol mouthrinse resulted in additional reported oral irritation relative to water rinsing.

Six-Week Clinical Trial of a 2% Hydrogen Peroxide Pre-Rinse

After 6-weeks adjunctive use, a 2% hydrogen peroxide prerinse showed no significant tooth color improvement versus regular toothbrushing.

All in all, given there are studies that cast doubt on the efficacy of these rinses in affecting any real whitening, and given other studies suggest they pose a risk to the health of the teeth, I will personally be passing on using anything like this.

[the1ndonly]

Thanks a lot Zoso for that informative answer. It helped a lot.