What does saliva do, and what if your mouth is always dry?

From the General dentistry guide

Saliva is one of your mouth’s main defences. It washes away food, neutralises the acids that cause decay and helps repair the earliest damage to enamel. When there is too little of it, cavities and gum problems become more likely.

What does saliva do?

• Cleans. It rinses away food and some bacteria.
• Neutralises acid. It buffers the acid that plaque produces after you eat.
• Repairs. It carries calcium and phosphate, which help rebuild early enamel damage.
• Helps you eat. It softens food, helps you swallow and starts digestion.
• Protects soft tissue. It keeps your mouth moist and contains substances that help control germs.

What causes a dry mouth?

Everyone’s mouth is dry sometimes. It becomes a concern when it lasts. Common causes include:

• Medicines, including some for allergies, blood pressure and depression
• Not drinking enough water
• Smoking and alcohol
• Breathing through your mouth
• Conditions such as diabetes
• Radiotherapy to the head and neck

What are the signs?

A sticky or dry feeling, thick saliva, trouble swallowing, cracked lips, a burning tongue, bad breath, and new cavities despite good brushing.

What helps?

• Sip water through the day
• Chew sugar-free gum to prompt saliva flow
• Cut back on alcohol, tobacco and sugary drinks
• Keep up fluoride toothpaste and daily cleaning between your teeth
• Ask your doctor whether a medicine could be the cause, but do not stop it without advice

When should you see a dentist?

Book a check-up if your mouth stays dry for more than a couple of weeks or you notice new decay. A dentist can check for damage and advise on protection. If a medical cause seems likely, they will suggest you see your doctor.