How Salt Prevents Tooth Decay- My Logic

Salt is very useful for oral health .. i had listened that fact many times. But, yesterday when i was brushing my teeth before going to sleep, suddenly a logic sparked in my mind. why salt helps fighting tooth decay though it is just another food element? and on the other hand sugar causes the tooth cavity, why so?. That was the conflicting fact to my mind. After that spark ,an another idea sparked in my mind and i think it is the

reason how salt prevents the decay in our teeth

[image source : http://blog.emergencyoutdoors.com/tala/uploads/2012/07/sixty-uses-of-salt-03.jpg]

Fact number 1 : Tooth decay is mainly result of acidic corrosion of teeth.

Fact number 2 : Sugar like food elements, after remaining between our teeth holes, convert into mild acids , which can cause tooth decay.

Fact number 3 : Salt is Basic element. i.e. salts are anti-material to acids. Their Ph is generally about 7. so they neutralize acids' effect.

Fact number 4:  It is well-known fact that salts are used to keep dead bodies preserved as mummies. So clearly salts prevents occurance of germs.

interesting...isn't it? these 4 facts prove that salt fights the acid produced in our teeths and mouth and along with that, salt fights germs. Thus neutralizes the mouth inside and so tooth-decay doesn't occur.