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Many people today have a significant focus on personal appearance. You might not think so from the way segments of the American male population are depicted in TV commercials, but for others, having glowingly white teeth that grab the attention of everybody seems to be a desirable feature. Stained, discolored, or yellow teeth signal to others that you don’t care how you appear, and you are only one step removed from being Neanderthal. Dental science has come to the rescue of folks who want to have a “killer smile” through a number of advances the public has come to quickly accept.

One such advance is the ability to whiten teeth which heretofore were an embarrassment to the person who always kept his lips together when smiling for the camera. “The appearance and colour of teeth are a common concern for patients across many populations and are associated with an increased desire for treatments that improve dental aesthetics, including tooth whitening.” The availability and efficacy of both “home-based and in-office based” products have made teeth whitening treatment safe and highly desirable when manufacturer’s protocols are followed.

Discoloration of our teeth occurs for various reasons, but two general categories of cause  exist. Food dyes, tea, coffee, iron, copper, and antibiotics (tetracycline) are examples of extrinsic staining (or staining from and external source).  Genetics, aging, antibiotics, fluoride, and childhood developmental disorders are examples of intrinsic staining. “Whitening is any process that lightens the tooth color.” Chromogens are organic compounds known to accumulate in the tooth (intrinsic), or on the tooth (extrinsic), and cause staining. Chromogens, then, are found in the things that stain our teeth and do harm either by external contact or internal contact through the bloodstream. 

Home-based whitening products are toothpastes, gels, and films (strips) available at the drug store or Walmart and are mild bleaching agents that are safe to use long term. In-office based whiteners are highly concentrated bleaching agents applied under professional supervision. They are stronger, more effective, but also have higher risks. “Risks commonly reported with tooth whitening include increased tooth sensitivity, and mild gingival (gum) irritation….the degree of these effects is directly related to the concentration of the peroxide bleach [whitening] component, duration of the treatment, and the non-bleach composition of the product used.”

So, what is it that whitens our teeth? The agent the bleaches teeth is peroxide, and several compounds contain it or produce it. Peroxides are used for in-office bleaching and are applied directly to the tooth enamel. Peroxides release other chemicals that break down Chromogens, the stain-causing chemicals. Peroxides are derived from the following chemicals:

  1. Hydrogen peroxide—very effective, but high concentrations cause tooth sensitivity and “root resorption” in as many as 80% of patients. It can cause microscopic damage to the enamel.
  2. Sodium perborate— hydrogen peroxide is released when water is added to sodium perborate. It’s bleaching effect equals that of hypdogen peroxide.
  3. Sodium percarbonate—bleaching effect is similar to 30% hydrogen peroxide.
  4. Carbamide peroxide—a compound containing hydrogen peroxide.
  5. Others—bromelain, sodium bicarbonate, sodium chlorite, PAP. These were all compared to hydrogen peroxide, and the best whitening occurred with hydrogen peroxide.

BOTTOM LINE: The best tooth whitening agents are HYDROGEN PEROXIDE and any compound which has hydrogen peroxide as a byproduct. 

Home-Based Whiteners use lower concentrations of hydrogen peroxide in the range of 6% because of the safety factor.

In-Office-Based Whiteners use higher concentrations of hydrogen peroxide in the range of 30%-35% under the close supervision of a dental professional.

Study after study has shown the psychological benefits of tooth whitening. In one instance of the use of a low concentration of hydrogen peroxide, “the positive effect of bleaching on quality of life…..remained effective after two years.” Along with the good must also come the bad, of course. In addition to increased tooth sensitivity and gum irritation, whitening causes “microscopic damage to the surface of the enamel,” “tooth surface roughening and softening,” and “the risk of root resorption.” Home-based treatments are less prone to cause adverse effects, but results take longer to obtain. Office-based treatments work faster, but have higher risks and demand close observation by dental professionals. 

Fortunately, there are also “natural teeth whiteners” found in the ingredients in “lemons, strawberries, oranges, papayas, and other fruits….[that] offer a milder and safer way of whitening teeth than whiteners containing hydrogen peroxide or carbamide peroxide.” Perhaps we all need to increase natural whiteners in our diets, plus stop smoking, and drinking coffee and tea. 

Dr. G’s Opinion: One personal regret I have is never trying to improve my smile. By the time cosmetic dentistry became vogue, I was beyond wanting to spend the money or invest the time. Twice I did try “bleaching” my teeth, but impatience with the results and lack of commitment sabotaged my efforts. Plus those clear strips you apply to your teeth were difficult to keep in place long enough to do what they were supposed to do. My dentist at that time made molded “trays” for my upper teeth, but I failed to follow through with that as well. I think I became discouraged when I didn’t see an immediate response. I do marvel at how white some people’s teeth are, but can only hope. As an adolescent a few of my friends had braces, but they were unaffordable at our house. So my teeth have been, and will remain, crooked. The dye is cast. I am pleased, however, that I still have all my adult teeth, haven’t had a cavity since childhood, and don’t have gum disease. I’d take that over white teeth any day!

Accuracy reviewed by Jerry Davis DDS and Corki Willyard, dental hygienist. 

References: Benahmed AG, et al. A Review of Natural Teeth Whitening J Oral Bioscience 2022 Mar;64(1):49-58.

Joiner A, Lou W. Tooth colour and whiteness: A Review. J Dent 2017 Dec; 67S:S3-S10.

Zimmerli B, Jeger F, Lussi A. Bleaching of Non-Vital Teeth Schweiz Monatsschr Zahnmed 2009 July 7;120:306-313.

Mueller-Heupt LK, et al. Effectiveness and Safety of Over-the-counter Tooth-Whitening Agents Compared to Hydrogen Peroxide in Vitro. Int J Mol Sci 2023;24:1956.

Carey CM. Tooth Whitening: what we now know. J Evid Based Dent Pract 2014 June;14 Suppl:70-76.

Bersezio C, Martin J, et al. Teeth whitening with 6% hydrogen peroxide and it’s impact on quality of life : 2 years of follow-up. Odontology 2019 Jan;107(1):118-125.

Kahler B. Present status and future directions—Managing discoloured teeth. Int Endod J 2022 Oct;55 suppl 4(suppl 4):922-950.

Shamel M, Al-Ankily MM, Bakr MM. Influence of different types of whitening tooth pastes on the tooth color, enamel surface roughness and enamel morphology of human teeth. F1000Res 2019 Oct 16;8:1764.

Blanchard D, van Wissen K. Home-based chemically induced whitening (bleaching) of teeth in adults: A summary of a systematic review. Public Health Nurs 2020 July;37(4):626-627.

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    1. Lookup the references cited at the end under “References.” There will be additional information I omitted from my essay.

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