Experts have pointed that the two factors - too little saliva and inadequate fluoride - and not good dental hygiene alone, that necessarily stop tooth enamel from decaying.
Saliva- It supplies high levels of calcium and phosphate particles that enhance protection of the tooth's enamel surface, which protects the teeth.
Also, it washes away food and the sticky film of acid-producing plaque that can cling to teeth.
But, certain medical conditions - Sjogren's syndrome, an autoimmune disorder, diabetes and HIV or AIDS - or their treatments can lead to dry mouth.
Inadequate fluoride: The exposure of teeth to this mineral can be increased through drinking fluoridated water and brushing twice daily with fluoride toothpastes.
It is an important enamel ally that can make teeth stronger and can enhance saliva's remineralizing, anti-decay properties.
Experts suggest people who drink primarily bottled or filtered water may not be getting adequate fluoride.