Next to your feet, some may say even before your feet, you need to look after your teeth.
Your teeth will be one of the key things that you will be unable to get fixed in the event of a survival situation yet you will need them to grind your grains, tear and chew at tough edible matter and, perhaps, defend yourself. If you cannot do these your chances of survival have been reduced. You are unlikely to have guaranteed access to soft foods or have your food softened by cooking or soaking. Never mind the pain you could suffer with an exposed nerve or damaged gums.
Even just a hundred years ago people went through a lot of pain and died early deaths because their teeth were rotten or broken. You want to avoid that.
So, plan ahead, make sure that in your supplies include items such as toothpaste, mouthwash and toothbrushes to help you keep your teeth and gums in good repair and for dental emergencies like broken teeth you need to make sure you have the equipment to deal with that. Dental tools like mirrors, scaler, probe, tweezers, oil of gloves, zinc oxide (filler) and forceps as well as standard medical equipment like gloves, antiseptics, syringes, needles, cotton wool and gauze.
An excellent book called ‘Where there is no Dentist’ is available from the Hesperian Foundation’s Online Library. Download, read and then prepare. I bought a hardcopy of this book several years ago and it is still as useful now. If you can afford it buy a copy to help fund updates and new information.