It has been noticed that Tibetan monks have healthy and white teeth to old age, even in ancient times when they have never heard of a dentist due to the fact they were living in the high mountain areas.
This is their secret:
Put a tablespoon coarse salt in half a cup of boiled and cooled water. Stir the mixture vigorously, using a spoon, for a whole minute and then remove the foam that will be formed.
Use your toothbrush to grasp a few crystals. Wash your teeth with this mixture doing the usual movements. Practice this in the morning and evening after meals (do not use this paste after eating fruit!).
Use the same water for rinsing your oral cavity. This way the teeth whiten and the gum strengthen and get beautiful and healthy pink color.
It is possible to feel a little discomfort at the beginning: teeth become sensitive to cold, hot and sour-sweet due to the saltwater. The sensitivity occurs because a small layer of the enamel is removed because of the salt.
The same properties will occur if you use expensive toothpastes for sensitive teeth. Anyway, you should refrain because salty paste will not only kill pathogenic bacteria in the oral cavity, but it will also strengthen teeth’s enamel i.e. it will “cement” the cracks and bumps on the teeth.