In America, water is fluoridated. It is chlorinated in the Soviet bloc. Fluoride is good for your teeth. From the tap in the USA they get such a good thing. But you google this thread. I saw it on TV.
It seems to me that the effect of a white-toothed smile is somewhat exaggerated. Some of course are chasing a snow-white and bright shade. But after visiting the circle of serious and successful people in the United States, it seemed to me that this phenomenon is treated as a bad taste, something like nouveau rish.
Such teeth look very artificial, not real and not natural. Healthy and natural color is considered beautiful. That is, of course, dentists also do it, but the appearance does not scream about it. And instead of the effect "I have money and I made myself teeth" you get the effect "I am healthy, take care of myself, I have good genes and I do not have to pay for my appearance." If an analogy can be made with breasts, this is a close example. What seems to be “ours” (not the fact that it is so) is accepted positively, in contrast to a deliberately made bust. A rigid, made breast with large scars in the fold under it and a snow-white bright color of the teeth seem to many people to be things of the same order.
I would say that "almost everyone" is an exaggeration. The stereotype of the whiteness of American teeth is largely associated with the spread of Hollywood cinema, and Hollywood, as you know, has special standards of beauty that are quite divorced from life. Another thing is that the Americans themselves are under the influence of these standards, which has allowed cosmetic dentistry to turn into a multi-billion dollar industry over the past decades.
The procedure for teeth whitening (by chemical methods, lamination, etc.) is one of the most popular services. in dental clinics, but in order to whiten your teeth, you do not have to make an appointment with the dentist. Many people go to beauty salons, to special kiosks in shopping malls (similar to our widespread express manicure and make-up points) or even to a pharmacy for a "perfect smile": since the late 80s, a huge variety of teeth whitening products have appeared in the USA at home, which can be found commercially. These include specialty gels, mouth rinses, chewing gums, sticky strips, which usually contain hydrogen peroxide as a whitening ingredient (ada.org). They are used primarily by those who cannot afford the services of a professional esthetician dentist, and as a result, they often acquire additional problems with their teeth, since the abuse of bleaching agents weakens the enamel. Therefore, for example, in economically less liberal Europe, there are stricter restrictions on the content of whitening components in over-the-counter dental care products.
So, Americans have perfect white teeth not because they are lucky with their genes : Compared to other countries, there should be no noticeable difference, given that America is a country of immigrants. Americans really pay increased attention to oral hygiene, but this has nothing to do with the whiteness of the teeth. "Hollywood Smile" is, first of all, an indicator of social status, the embodiment of the cult of personal success, and at the same time an artificially programmed need, which is intensely fueled by the advertising budgets of private dental offices and manufacturers of bleaching agents. Therefore, when we judge Americans in general by the teeth of American actors and actresses, politicians, TV presenters, American businessmen and tourists traveling the world, or even American expats living in Russia, this is not a completely representative sample. The population of the poor American hinterland will most likely have teeth that will not differ much from the teeth of an average European or even a Russian.
To the credit of Americans, it should be noted that many of them are not alien to self-irony about the obsession of compatriots with the whiteness of their teeth. To paraphrase a satirical post on the popular resource The Onion, "Hey Americans, it's good to compare your teeth by color to the refrigerator!" (theonion.com).