I'm planning to live in the wild for a year but I'm concern with my teeth... I'm thinking of What's the best toothpaste you can get in the wild?
Which I could use 3 times a day in a year.
It depends what do you mean by "the best" toothpaste. Toothpastes work by mechanical surface abrasion, so they scrub the plaque and remains of food from your teeth. If toothpaste is overly abrasive, it can damage your enamel, so it is important to find one with some proper abrasiveness level. Also, your brushing technique and used brushing tool are very important.
Abrasiveness of different toothpastes might be estimated using some special procedures (e.g. Relative Dentin Abrasivity method, PMMA Abrasion Test), index scores might be calculated, some safe range values can be established and toothpastes can be categorized into "low", "medium" and "highly abrasive". There is quite a lot information about this on the Internet but I was unable to find any reliable (and free) source to quote any values. Also, I haven't seen any research on substances occuring in the wild. But this is a direction you can go: look for research publications about RDA measurement of different wild-occuring substances. Bear in mind than low abrasive ones might not be better than simply bruishing with water. Also, remember that all of this is just an estimation - and a very rough one. You can read about it in "Toothpastes" by C. van Loveren et al.. Quote from it:
RDA values are not intended and should not be used as prediction tool of dental abrasion, since it does not reproduce the complex multifactiofial nature of the toothbrushing abrasion process clinically.