The reason your mouth waters over a juicy steak and the reason babies drool when they are teething are the same reasons you drool in the dental chair. Salivary flow increases while you're sitting in the dental chair because dental procedures stimulate saliva glands.

"Controlling saliva is necessary because saliva makes it difficult to see and work," comments Academy of General Dentistry spokesperson Charles H. Perle, DMD, FAGD. "It's like working under water."

A patient's mouth needs to be dry for the dentist to complete many procedures. Additionally many of the products dentists use, such as adhesives, amalgams and bonding materials, don't work effectively unless they are placed in a dry environment.

To keep the mouth dry, the dentist may use cotton rolls, rubber dams or high-speed suction, individually or in combination. Some patients' drool can be excessive, which makes dental treatments more difficult. In these cases, Dr. Perle says medications that alleviate the problem are available. The medication is short-term and allows the dentist to work in a saliva-free environment.

"Everyone drools now and then. It's natural, and something dentists deal with every day," says Dr. Perle.