hello
thanks for your concern
its good if you drink 4-6 lts of water daily but first of all we should find out the underlying causes of dry tongue. these are-
-side effect of certain medicines , some diseases &infections, some medical treatments
-
nerve damage
-
dehydration - surgical removal of salivary glands
-
smoking , chewing tobacco and mouth breathing
...so dear may be these causes can help to find the root of your dry tongue.
if you do then please consult your general physician as soon as possible.
for the meanwhile try following-
..suck sugar free candies or chew sugar free chewing gums
..drink plenty of water
..protect your teeth by brushing with flouridated toothpaste as
dry mouth can lead to caries in your teeth
..visit your
dentist regularly
..breath through nose and not mouth
..use room vapourizer to add moisture to your bed room air
take care
hope it helps