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Health & Wellness

The Truth about Teeth Whiteners

SDM prof weighs in on over-the-counter remedies


Americans reportedly drop $1.4 billion annually on nonprescription teeth whitening products to bleach away the effects of cigarettes, coffee, red wine, or just plain age. Certain medications, notably tetracycline, also discolor teeth, says Gennaro Cataldo, a Henry M. Goldman School of Dental Medicine professor of general dentistry.

But is the bite to your wallet worth it?

The government doesn’t regulate whiteners, warns Cataldo, and “many of them are ineffective.” On the other hand, some do work. BU Today asked him sink his teeth into the topic.

BU Today: To what degree is losing that pearly white shine unavoidable and natural?

Cataldo: Almost universally, teeth will get darker with age. For most older people, their teeth will turn kind of a brownish yellow—not necessarily from smoking, from coffee, or wine. Our hair turns white, and our teeth turn yellow. I wish it were the other way around. Other teeth turn out to be grayish. There’s a whole spectrum of what is normal.

Whatever the cause, are over-the-counter products effective?

There are two types of discoloration: intrinsic, the one that develops with time and is the natural color. Then there’s extrinsic color due to deposits on the teeth from smoking or coffee or other materials or due to medication taken by the patient—or by the mother when the patient was in utero. We also have patients who just don’t take good care of their teeth.

Bleach will not work with a stain from major deposits caused because a patient has not brushed their teeth. If we’re not taking care of our teeth, we’re not going to get a very effective whitening from any type of product. The teeth have to be in a healthy condition; if a patient hasn’t been to the dentist for a while and if there are any cavities or decay going on and the whitening material gets within that cavity, it can cause excruciating pain.

So we have to start with teeth, gums, a patient who is healthy. Then, over-the-counter whitening agents can work effectively. But because it’s not dentist-monitored, many of them don’t do anything. For instance, a mouthwash containing a whitening agent such as hydrogen peroxide probably is not going to be very effective. There are some products that use a light that we flash on our teeth to accelerate whitening. Even the whitening lights that we use in the dental office are no more effective than other ways of whitening teeth.

If you want white teeth, dentists have tried-and-true methods. Some allow us just to paint on a whitening solution to sit on the teeth a half hour, 45 minutes in the dental office. Totally different from the material you buy in the drugstore. It’s highly concentrated; the gums actually have to be protected from this material.

Absolute White UV teeth whitening system, over the counter teeth whitening products

Absolute White UV teeth whitening system. Photo by Dave Meyer

Are there any over-the-counter products that you would recommend?

Crest Whitestrips work. There are trays which are purchased in the pharmacy, put into water and heated, and placed into the mouth to mold the tray to the patient’s mouth. Then whitening agent is put in. Those work. I said mouthwashes wouldn’t whiten your teeth, but if you’re going to be rinsing six to nine times a day and holding it in your mouth for a couple of minutes, and you’re going to do this for two or three months, we’d probably see a whitening occur. Look at the label—they’ll have some type of peroxide.

But there is no guidance by a dentist to monitor all this. Are the gums becoming irritated? Is the patient overdoing it? Are there cavities that are going to get sensitive because of this material? Will the teeth become as white as what is done in the dental office? Probably not as rapidly. It might take two or three months with over-the-counter products, whereas when we use products that can only be purchased in a dental office, those are going to work within three or four days to a week or so.

Does dental insurance cover teeth whitening?

Mostly not. That’s a cosmetic procedure.

How often should a person whiten his or her teeth?

I can speak to the products we use in the office: when we whiten, usually it will last about two years. I generally recommend patients touch up that bleaching every time they have a cleaning on a six-month basis.

The recommended procedure, and least expensive, is a home bleaching procedure. The dentist takes an impression of the patient’s mouth and from that impression makes a whitening tray. It fits in the patient’s mouth like a mouth guard. Whitening material can be placed inside in a gel form. Some people wear them overnight, while they’re sleeping; other patients wear them during the day because they’re virtually invisible. This is meant to be worn for an hour or two, once a day. It’s plus or minus $500.

I think any over-the-counter product can be harmful, because it can be easily misused or overused. As a matter of fact, whitening materials in the dental office, over a prolonged period of time, could probably do harm. We don’t know for certain. We have had patients come in who had a burn mark on their gums because they’ve overdone it. This is all reversible harm, but we’ve had patients for whom we have gone through the home bleaching, they did the right thing, and they called a day or two later in excruciating pain. They were sensitive to the material. They could still bleach; we had to adjust the concentration and how the tray was fitted to their mouth.

Bottom line: if you want to whiten, you should consult your dentist first, and even then, beware that whitening can have problems?

Whitening in general can have problems. It’s very rare. But this is what dentist-monitored whitening is about, to make sure that you’re doing it effectively.

Rich Barlow, Senior Writer, BU Today, Bostonia, Boston University
Rich Barlow

Rich Barlow can be reached at barlowr@bu.edu.

49 Comments on The Truth about Teeth Whiteners

  • Someone on 04.25.2012 at 1:28 am

    Everything I love is bad for my teeth D:

    But the CVS knock-off whitestrips are decent in my experience.

  • Jane on 04.25.2012 at 9:37 am

    Dr. Cataldo did not address the chemistry that occurs at the tooth’s surface that is part of the whitening process. My dentist told me that hydrogen peroxide, which is used in many or perhaps all teeth whiteners that are on the market (over the counter or not) removes stained tooth enamel… and it’s a permanent loss. Additionally, he said that toothpastes with whiteners actually have fine grit in them, so essentially the user is sanding off the protective enamel coating over time. He said that no one should be whitening his/her teeth. Would Dr. Cataldo agree?

    • Dr. Cataldo on 04.27.2012 at 9:53 pm

      The hydrogen peroxide that is in most tooth whiteners has absolutely no effect on tooth enamel other than to remove the stain. No enamel is lost during the process.

      However you are right with your comment that abrasive toothpastes can, over time and with excessive use, cause loss of tooth enamel through abrasion.

      Dr. Cataldo

      • Jose on 03.19.2013 at 9:10 pm

        Hi. This is sgt Rodriguez my teeth has been yellow since I been a teen. And now I’m in the army and I’ve bleached my teeth 3 times but it does not work on me. The first time they really whiten but the second and third they did not. What can I do to whiten my teeth

  • The Health Paradox on 04.25.2012 at 4:21 pm

    Just wondering what kinds of toxicological tests have been done on these whitening products (over the counter or not) to insure they are safe for people? What type of epi studies have been done on the effects of using these?

    Many cosmetic products that we can legally buy from the grocery store contain toxic chemicals in them. I’m not one to assume something is safe just because it’s used a lot.

  • Jane on 04.26.2012 at 12:08 pm

    I would like to know whether Dr. Cataldo or SDM has any financial conflicts of interest involving this story. BU Today’s reporters would do well to ask the medical doctors (MDs, dentists, podiatrists, etc.), who opine about a procedure or product, about their conflicts of interest and report on that. Medical ethics requires that researchers and doctors reveal their conflicts of interest and BU Today probably should not be in the business of allowing them to circumvent that requirement. We readers do want to know. Please, report on it in the future. Also, I am hopeful that Dr. Cataldo will comment on his financial conflicts of interest in any company that produces any kind of whitening product or supports a particular procedure involving a commercial instrument, etc.

    • Erin on 01.24.2017 at 9:46 am

      Say “conflicts of interest” just one more time. The 15 times mentioned wasn’t enough for me. Do you really think Crest is endorsing him to briefly mention their product in passing in some obscure article on the net?

  • Iris on 04.27.2012 at 4:20 pm

    Interesting article. After having tried a few OTC whiteners, my strong gut instinct is that teeth whiteners are very bad for your teeth.

  • Dr. Cataldo on 04.27.2012 at 9:57 pm


    Be assured that I do not have any financial interest and am not involved as either
    an investor or researcher for any dental whitening product.

    Dr. Cataldo

    • Jennifer on 04.24.2015 at 10:16 am


  • Jonay on 07.27.2012 at 8:23 am

    Interesting article, I am used to pick up the whitener toothpaste, not anymore, thanks! I have to start to cut in sguray stuff as well :-)

  • jimbo on 10.24.2012 at 5:52 pm

    While I to have caution about using diy white kits this comment by Dr. Gennaro Cataldo is too biased. People could hurt themselves by swallowing mouthwash. Why doesn’t he recommend dentist supervise them? Maybe because dentist can’t make money from it? Without real good body of medical research to support(which there doesn’t appear to be?) its use or none use its all anectdotal right now and so far based on that diy whitening doesn’t have high harmful risk to it.

  • Jennifer Monny on 12.12.2012 at 9:25 am

    please explain very well for me the effects of teeth whitners…i didn’t really understand.

  • Sammy Dolan on 03.12.2013 at 4:15 pm

    Be careful that you use a bleaching kit that does not contain peroxide. If ingested peroxide can be very dangerous so if you are planning on whitening your teeth at home use a non-peroxide kit.

    • Brenda Labelle on 03.04.2015 at 6:27 pm

      Actually peroxide is not as bad for you as you make it out to be. There are some medical procedures that rely on a patient actually taking in a certain percentage of peroxide each day. Also there are machines that you plug to your water tank that provide a certain level of peroxide in your water. Taken on regular basis this peroxidized water actually helps kill many bacteria and is also known to cure hepatitis C in many patients. Some research on the internet will back my claims.

  • Rosh Zami on 05.13.2013 at 2:08 pm

    Choosing best teeth whitening product amidst the completely different teeth whitening merchandise available in the market in the present day might be very confusing. When you ask the consultants, they will tell you that the very best technique of enamel whitening continues to be by means of your dentist. Not only is it the most effective, it is also the best and the quickest to have whiter teeth. However then, not all folks can afford the charges that come with every treatment. Another factor that hinders them from going to dentists is fear. It appears that evidently as early as childhood, dentists are one of the most feared personalities that people do not wish to encounter.
    Although dentists do not advise folks to decide on enamel whitening products, they all agree in saying that these products are effective in some degree. According to research, tooth whitening products, if used usually and persistently may end up in whiter enamel that can outlast any dentist-assisted procedure.

  • Leigh on 05.24.2013 at 9:36 am

    I once had a dental treatment for whitening that cost about $500 dollars. I didn’t notice any difference. I decided to try crest white strips when they initially came out and it worked magically. I’m in my twenties and have always taken really good care of my teeth, not a smoker or coffee drinker… the results for the white strips lasted years for me. Whitening mouth wash is basically watered down hydrogen peroxide as far as I understand. I’ve heard of people adding hydrogen peroxide to their mouth wash and seeing good results. Not sure how safe that is especially with prolonged use.

  • lana dee on 07.28.2013 at 10:01 am

    Thank you so much for writing this. I finally understand about having white teeth. I am older and my teeth are darkening and I blamed it simply on my coffee drinking. As this is a natural progression as one ages, I am going to relax and enjoy my coffee :)

  • Ernestine on 11.24.2013 at 5:46 am

    Of course Dr. Cataldo has a financial interest in this. Of course he is biased. Dentists make money by selling teeth whitening to their patients. Do you really think there would be OTC teeth whiteners if they did not work? A lot of Dental Societies & Associations have been getting in trouble by the feds recently for monopolistic behavior by outlawing teeth whitening kiosks and beauty salons that offer teeth whitening. The Federal Trade Commission, FTC recently successfully sued the NC State Board of Dental Examiners for this aggressive behavior. The State Board has filed appeals but lost them too. Currently the Institute for Justice along with teeth whitening entrepreneurs is suing the State of Alabama as well as the State of Connecticut as well. The FTC has plans to aggressively go after other State Boards where teeth whitening has been outlawed and therefore competition eliminated causing the price for teeth whitening to stay upwards $7-800, while the entrepreneurs charge $125-175. You can of course easily Google all of this to learn more. They also all use the same materials with NO complaints to the FDA. Interestingly the only complains regarding teeth whitening have been for the dentists and Zingers (hideously awful pain that randomly shoots through your mouth) using the ZOOM machine which only dentists use. The FDA feels that what the dentists have successfully used for over 20 years is safe enough for it not to be classified. Not surprisingly the American Dental Association, ADA has lobbied them time and time again to regulate. Dr. Cataldo is just looking after his own. There should have been opinions from other schools of thought. The product manufacturers and the teeth whitening entrepreneurs. Not a very ethical piece at all. Shame on all of you. Very disappointing indeed.

    • Jon on 03.08.2014 at 2:37 am

      Yes, OTC products work but they are typically not as effective. The same basic principles are at play but the materials dentists use are higher concentrations. Additionally when a dentist makes a whitening tray it is custom fitted to the individual and covers the whole tooth and should not go onto the gums unlike OTC products. The reason why “entrepreneurs” charge less is because they are not doctors. If you would rather have a high schooler in a mall conduct your dental care that’s up to you. You can also go to third world countries for cheep medical treatment. You may have no problems at all, but then again you might. Personally I think it is best not to let technicians carry out dental or medical treatment. I find it interesting how many people make comments as if they think they know what they are talking about. Dentists try to simplify for people but nothing is simple. Go to school, study chemistry, organic chemistry, biochemistry, physiology, microbiology, and combine all the principles you learn through four years of study incorporating tooth physiology and chemistry along with histology pathology and then maybe you will understand how some of the processes really work within dentistry. Until then, just take the experts word for it.

      • Ernesto on 12.17.2014 at 5:16 pm

        there are some jobs done by doctors and others done by nurses. Teeth whitening does not require a dentist, just like cleaning your teeth once every 6 months can be done by a dental hygenist

        • LindaLee on 04.15.2016 at 5:14 pm

          You are correct a dental assistant can do the actual cleaning/whitening but I think b/c the whitener is high strength only a dentist/doctor has access to the actual product they use?!?

  • jod on 01.17.2014 at 8:10 pm

    I just paid 500.00 for a dentist whitening using Kor whitening. First they did a in office treatment that took 2 hours then fitted trays with gels to wear nightly, should be done and look great in 2 wks, 3 at the absolute most. 2 wks barely could tell, buy more gel and then told I may need to wear trays for 6 weeks at 50.00 per week. At the end of week 3 my lips swelled and the whole inside of my mouth is raw and blistered. I went to the dentist and he said to give myself a week off then resume. I did this because I was getting veneers on my two front teeth and wanted my teeth to be as white as poosible before matching the veneers. Havent used trays for 4 days and my mouth is still raw and very painful. I’ll try Crest strips if I ever heal up and may skip veneers all together.

    • Chris on 06.26.2014 at 11:29 pm

      Ok you are telling me that your gel you put in a tray is more concentrated than the paint on gel I use at my salon. I have been a cosmetic teeth whitening professional for over 10 years. I use a water based 16% hydrogen peroxid paint on gel. Now why don’t you tell the people the truth. If you are using trays the most you are using is 44% carbamite peroxide which has a 3 to 1 ratio to hydrogen peroxide. If your a true dentist you should know anything higher the 12% hydrogen peroxide in a tray would kill a persons gums. Now zoom is different most dentist use 22% or 35% hydrogen peroxide with a gum guard solution. Does it work yes but at a cost of a lot of pain and money. Which by the way insurance doesn’t cover. Look I gave a fantastic product my 7 location I do 40000 teeth whitenings annually. Do you get complaintsunami yes abut 7 in ten years from consumers. How many complaints from dentists in ten years 726. Tell the consumer the truth I’m a dentist and I’m going to get my $300 An hour no matter how I get it. By the way my prices are $99 $149 and $199. 1/4 less then any dentist.

      • Ernesto on 12.17.2014 at 5:15 pm

        Chris do you use a UV light with your treatment and if so are the lights effective? Thanks!

  • Jaqueline on 06.06.2014 at 6:05 am

    I have tested 4 OTC systems, one Dentist provided and various naturopathic methods including peroxide/water “pull” (swish) 3x/day as indicated on the bottle.
    For the money, ease of use, comfort and effectiveness, various whitening strips have worked best for me despite the fact that I have trays molded specifically for my teeth. This having been said, reputable OTC gels are only slightly less effective (in my case), yet they are a bit more of a hassle combined with your personally fitted trays due to the difficulty in the cleaning and maintenance of the trays as well as comfort in wearing them which will dictate whether or not you use them as directed.
    I myself, am reading through this site because I have yet to determine the BEST BRAND of OTC whiteners. Anyone use Rembrandt before? Anyone have a favorite? Thanks.

  • Vicki on 08.13.2014 at 3:14 am

    What about oil pulling? I’ve heard a lot about using coconut oil lately. Has anyone tried this? If so, what were your results?

  • Peter on 09.26.2014 at 10:54 am

    I have tried many methods as well and lost quite a lot of money because of it.

    I will tell you – it is not worth it. You can achieve same or even better results with home made remedies – just get some cheap ebook with teeth whitening guides like this one http://ponvu.com/teethwhitening and you will know what i am talking about.

    good luck!

    • Brenda Labelle on 03.04.2015 at 6:41 pm

      This is a HUGE SCAM!! Why a kit if the products are things we have in our kitchen or can buy at the store? I did research on this site and it is a bunch of BS* The mouth showing the yellow teeth become so white has been created electronically or through a simple dye process. If there was any truth in these claims, it would not be a product that is sold but just plain telling people how it is done. SCAM SCAM SCAM. Shame on you for putting your link here to make a few bucks.

  • Big Jibbs on 12.03.2014 at 9:31 pm

    Look up Opalescence PF 35% Teeth Whitening.

    It’s the same stuff dentists sell but for over half off the price they beat you up with.

  • Ernesto on 12.17.2014 at 5:14 pm

    My question for Dr. Cataldo is simple. There are dentist offices that use whitening UV lights as part of the whitening process. Are you saying that there is no benefit in using such lights? Thanks

  • Lilian Burwell on 03.09.2015 at 9:06 am

    I’ll be 90 years old in 2 years! I have healthy dental habits and condition. I stopped smoking 40 years ago. I use whitening toothpaste regularly, but see no improvement. Should I give up because of my age? What do you recommend?

    • LindaLee on 04.15.2016 at 5:27 pm

      I would stop using the whitening toothpaste until you decide what to use, especially if it isnt working, it is gritty and actually can wear away your enamel and make your teeth sensitive, you might have to ask a dentist, as if the discolouration is from aging, you could end up wasting a lot of money and doing some harm..sorry not more helpful

  • Mike Whitening on 04.01.2015 at 12:52 pm

    Never knew people spent that much on vanity products in the USA! It would be nice if most engaged in lifestyle changes for best permanent results in whiter teeth.

  • Stella on 05.17.2015 at 8:43 am

    We have seen that Crest Whitestrips and Kroger Brand Whitestrips work the best, but you must be careful how often you use them. They can actually damage your tooth’s enamel and have long lasting side effects. I know we all want Pearly White Teeth, but you must make sure you take proper care of them first.

  • Derek Cormier on 05.29.2015 at 5:35 pm

    Listerine restor whitening works for me. Two shades whiter in 3 weeks. I rinse with it longer than the suggested minute though. My teeth are stronger than ever at age 39 . I also rinse 4-5 times daily. Definitely recommend.

  • Linda (Texas) on 07.17.2015 at 7:30 am

    Had whitening done three days ago at my Dentist’s office. I am 68 and practice excellent oral hygiene. As a child I had severe rheumatic fever. As result, into adulthood I needed a great deal of crown, bridge, and root canal work. My front uppers became discolored to the point of extreme self-consciousness. I had four 15 minute applications with blue light. The prep especially the ‘device’ was unpleasant. I toughed it out. Thought I would faint, vomit, pass out or all three, the bleaching was so painful. I am still in pain. My whole mouth hurts. I only had four upper teeth (8, 9, 10, 11) done. I have endured broken bones, abscesses, frozen shoulder, root canals, etc. the worst pain ever was trigeminal neuralgia. This was so much worse! I’m tough, but I have been physically ill from the after pain. I drink coffee, eat lots of dark cherries and blueberries and I am a smoker. This has/is worse than all pain I’ve ever had except trigeminal neuralgia. Would I do it again? Maybe. I am very happy with the results. I was given a fitted tray and enough gel to last two years. The total cost was $260. Yes, I suppose I would do it again. If your teeth embarrass you, by all means I recommend. But, do it in a good Dentist’s office.

    • me on 02.20.2016 at 7:41 pm

      Good god. If the pain is that serious why not just get veneers?

  • john on 09.15.2015 at 3:59 pm

    What about buying zoom(teeth whitening products)from say Amazon and using them at home?

  • Debbie on 09.28.2015 at 3:22 am

    I’ve decided to try lemon juice and baking soda or salt mixed into a paste as read by a dentist this works just as good. I’m not brushing my gums I’m going to painstakingly try to do each tooth without touching the gums as my teeth are very sensitive.

    • LindaLee on 04.15.2016 at 5:39 pm

      I am surprised a dentist told you that, did they tell you how often? Peroxide based whiteners I was told work best, lemonjuice and baking soda paste will be very abrasive and I would worry about damaging my enamel and tooth sensitivity with repeated use, but if thats what they say to use, Arm&Hammer makes baking soda toothpaste it might be a little easier to manage and less irritating to your gums?! Good Luck, i know it is so frustrating!!

  • Judi on 02.11.2016 at 1:23 pm

    I buy opalescence on eBay now for my dental trays. Extremely affordable.

  • duawanita.com on 09.24.2016 at 10:15 am

    now there are electronic tool to whiten teeth, if this can cause dangerous side effects?

  • Doug on 03.07.2017 at 10:41 pm

    I use white-out..simply dry-blot your teeth, hold lips up, and apply white-out.

    • Violetta on 08.16.2018 at 12:59 pm

      Best answer yet.

  • Alex_DDS on 12.04.2018 at 11:45 am

    I have a question for the colleagues who perform Zoom whitening treatment. Has anybody heard about the possibility to save on performing the treatment buying a special chip from bleach-infiniter.com which is simply inserted into a standard light guide for Zoom machine and makes it unlimited? That being said that it allows easily to use all remaining gel from a standard Philips kit to serve another patient or even start using third part bleaching material to reduce the cost of the procedure. I have heard that many dentists started using Beyond and other whitening kits along with Zoom light. I suppose almost any light-activated gels could be used as far as I understand. Any suggestions?

  • Parker West on 01.14.2019 at 11:44 am

    There is a little more to carbamide peroxide teeth whitener than strips or liquid poured into trays, it’s the percentage % of carbamide peroxide in the application. I’ve tried them all and if an OTC product can be found using a different agent I have not seen it. Anything under 10% is worthless, you’ll have to use it daily for 30-60 minutes for very little improvement. On the other extreme 35% will burn your gums and case pain. 22% works OK for me and I use it once a week for 30-60 minutes. If you repeat the application and it hurts space out the uses. If your gums are white just below your teeth, the product is too strong or used to often.

  • Jesse Varnum on 02.06.2019 at 1:56 pm

    Interesting article, I am used to pick up the Whitening Strips, not anymore, thanks! I have to start to cut in sguray stuff as well :-)

  • Nathalie Fournier on 03.04.2019 at 11:31 am

    I have a question regarding teeth whitening products from China. I have used the herbal Medicine whitening liquid and it had a weird result. It talks about a certain bacteria that can bring teeth to a brilliant white, but the result I had after the first use was not really what I hoped for. It left my teeth whiter yes but also had a mat finish with a rough feeling instead of a silky shining brilliant finish. And after I noticed that coffee and cigarettes were staining my teeth right away. Is this stuff bad for my teeth and how can I get the shine back without harming the enamel?

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