This condition is sometimes called xerostomia, but it is most easily recognized with the simple term ‘dry mouth.’ Unsurprisingly, it is caused by a lack of saliva in the mouth. This can occur for a number of different reasons, but it is a well-known side effect of taking prescription medications. If you are on any kind of drugs, ask your doctor whether this could be an issue.
The risky thing about dry mouth is that it robs the gums and teeth of essential moisture, lubrication, and cleansing. Saliva actually has mild antibacterial properties and it is used to wash away unused plaque from teeth. So, without it, bacteria is allowed to remain on the enamel and starts to eat.