Although not really a matter of "medicine" and a bit of a tongue-in-cheek mention is the preservation of teeth, in particular the prevention of cavities, broken teeth and other assorted issues. Most of the troubles with bad teeth, in particular cavities, are really almost all reducible to bad teeth care such as the lack of brushing, flossing and proper observation of the bio-mechanical system that comprises the jaws, the teeth and the gums. The situation with bad teeth has become better over the years, remarkably, only traceable to knowledge and the dissemination of knowledge to people at large that have started to adopt the habit of brushing teeth more than ever before.

The bio-mechanical system governing the consuming apparatus of the human body is easy to preserve and not destroy even by applying the common-sense knowledge of every day activities, such as:

• Hard stuffs, like nuts, should not be crushed with the teeth; in fact, humans in the first world have had a reduction of strength in their mandibulas compared to people that remained in developing areas with "modern" humans being more accustomed to eating the nicely cut and softened food on the market. Either way, the mechanical strength combined with the shatterable porcelain of the tooth, make this one a no-brainer, and using teeth for mechanical work is a very bad idea.
• Just like food rots in nature and attracts microbes, so does food rot greatly within the mouth and in-between the teeth, leading to interstitial cavities that superbly can destroy two adjacent teeth at the same time and with only one small piece of forgotten meat! When a piece of food rots hidden way back in the dentures with the foreign food not being detected by the owner of the teeth, the biochemical processes start to attack both the gums and then the teeth themselves.
• Gums are really just soft skin so be weary that they cannot do much on their own if not taken proper care of. There is no magic here: the bio-mechanical apparatus should be used to eat any food desired but also one has to make sure that this apparatus is cleaned out after use. Eating food, even chips can sometimes scratch the gums which leads to sores and, in turn, that can also lead to infections.

The tools of the trade are:

• Toothbrush and toothpaste; the toothpaste is mostly irrelevant and you should pay no attention at all to the text on the toothpaste. If no toothpaste is available, then a mixture of bicarbonate and water can provide an alkaline (acid nullifier) and a mild abrasive in order to wash teeth. Pastes or "whitening pastes" should be avoided at all costs because they all work on the mechanical principle of containing microscopic stones that literally polish the teeth. There are bio-chemical variants, and even optical ones such as UV treatment, but be aware that these solutions attack the material of the teeth, just in various forms. Teeth dust or paste will scratch, bio-chemical will bite into the chemistry and UV will also attack the material itself.
  • Brushing teeth is not a matter of intensity or "session"-length, but a matter of how many times per day the brushing is performed. The purpose is to eliminate what was mentioned in the previous section: food remains, garbage, grime, smoking tar, etc, and throwing toothpaste onto the teeth does not result in a "magical result". The idea is to keep all foreign agents off the teeth.
  • Perhaps, the best time to actually insist with brushing teeth is really before night-time and before going to bed. This judgement is again, purely physical, not medicinal in any way, and relies on the observation that a human being sleeps 8 hours, during which the teeth are not used at all and the bacteria and bugs are free to roam inside the mouth!
  • There are toothbrushes and toothpaste that, just like other medicine, come "bundled" with other stuff (yeah, just like adware in software but for medicine). Most of the time, the additives do not really make too much sense. For instance they advertise for extra fluoride or other tooth components, yet these vitamins should rather be in the blood stream not just thrown onto the tooth! Applying fluoride to teeth to "strengthen them" is akin to throwing a brick at a brick wall to make the building stronger. It won't work. Intuitively, medics might flip and say that the absorption takes place though the gums because the mandibula is also a capillary area, but one has to consider that these are "trace amounts" that are applied instantaneously and then washed off a few seconds after rinsing so any pretense of absorption is vain.
• Interstitial cavities are easy to make by trapping food between teeth and the best cure is flossing. Interestingly, food has a way to "wrap around" teeth, such that using a regular toothbrush will not manage to pull or push the remains from between the teeth. Dental floss is a rope that can be used for that purpose that slides between the teeth where a toothbrush would not reach and (again, mechanically) pulls out the foreign body. In many ways, flossing is more effective than brushing, but only when it pertains to pulling out stuck bits of food because brushing the teeth also has the effect of removing plaque or grime accumulated on the surface of the teeth themselves.

Lastly, and this one's our favorite. "Listerine" is a substance that at first sight contains some ingredients that are not too spectacular in any way. Listerine has been even called literal "snake oil" many times, reminding one of the Rothshield business of selling, well, literal snake oil. The thing is that, in hindsight, the idea to use this substance, maybe even like snake oil, is not too much of a placebo but rather a very useful practice concerning mouthwash. If you have never used Listerine before, Listerine feels and tastes almost like drinking pure vodka, including a terrible feeling of mouth burning when held within the mouth for lengthier periods. The thing is that, regardless of the "bling" ingredients, one has to consider that the bottle is mainly one giant alcohol bottle such that holding (almost pure)alcohol in the mouth on the regular, completely obliterates any bacteria in the mouth and acts like an antiseptic for small cuts to the gums. Chlorine and alcohol have been two substances used by humans historically that tend to clean right about anything, such that applying alcohol to the teeth has the effect of also removing grime and plaque or, most commonly, softening it up. With that said, the process can be combined, some people prefer using Listerine before brushing the teeth in order to moisten any grime or other small bits of food, and then using the brush to wash all that off. Others, prefer to brush and then settle with some Listerine. Either way, daily use of Listerine, maybe at two or just one usage per day, just before night time, can almost guarantee no cavities.

As a bonus and an additional homage to "Listerine", it is interesting to mention that "Listerine" can help in case an individual does not want to extract their wisdom teeth, yet the teeth are growing through the gums and potentially creating infections. The solution is simple, but a little costly given the price of Listerine, and it requires multiple daily washes with Listerine as well as the usage of some minor painkillers from time to time.

As the tooth breaks the gums, there are lesions created that can get rapidly infected, but Listerine and the alcohol within can keep the lesions disinfected and then they are hopefully healed by the body (better for people not suffering from a low white blood count, like people suffering from anemia). The painkillers just help deal with the pain as the teeth grow and start pushing against other teeth.

The combination of Listerine and painkillers can prevent a visit to the dentist to have those teeth extracted.