The short answer: Saliva protects your teeth. It washes away food, neutralizes acids, supplies the calcium and phosphate that repair early enamel damage, and helps keep germs in check. When your mouth is often dry, cavities, fungal infections and bad breath become more likely. Medicines are a common cause. Sipping water, chewing sugar-free gum, using a humidifier at night and cutting back on caffeine, alcohol and tobacco can help, and a dentist can add extra fluoride.
Dry mouth is more common than many people think. Pooling 29 population studies, a systematic review estimated that about 22% of people have it (95% confidence interval 17% to 26%), with higher rates among older adults (Agostini et al., 2018).
This article explains what saliva does, what causes dry mouth, why it puts your teeth at risk, and which home measures and treatments the evidence supports.
Prefer to watch? Here is this article as a 7-minute video.
More short videos: see them all on our Videos page or subscribe on YouTube.
What does saliva do for your teeth?
Saliva is mostly water, but the proteins, enzymes and minerals in it give it several protective jobs (Dawes et al., 2015):
- Repairing enamel. Saliva is rich in calcium and phosphate, the minerals tooth enamel is made of, and contains bicarbonate that buffers acids (Dawes et al., 2015). Helped by fluoride, these minerals let early, microscopic acid damage repair itself, a process called remineralization (Featherstone, 2008).
- Cleaning. It continually washes food particles and acids out of the mouth (Dawes et al., 2015).
- Fighting germs. It contains antibacterial, antiviral and antifungal substances that help keep the microbes in the mouth in balance (Dawes et al., 2015), including some that act against cavity-causing bacteria (Lenander-Lumikari & Loimaranta, 2000).
- Digestion, chewing and speech. The enzyme amylase starts breaking down starch, and slippery proteins called mucins coat the mouth so you can chew, swallow and speak comfortably (Dawes et al., 2015).
That repair process is why early decay can sometimes reverse; see whether a cavity can heal on its own.
What is dry mouth (xerostomia)?
Xerostomia is the feeling that your mouth is dry. It usually goes with salivary gland hypofunction, which is a measured drop in how much saliva you make (Plemons et al., 2014). Symptoms include a sticky, dry feeling, trouble chewing, swallowing or speaking, a burning feeling, cracked lips, mouth sores and bad breath (National Institute of Dental and Craniofacial Research, 2024).
What causes dry mouth?
Medicines
Hundreds of medicines can make the salivary glands produce less saliva, including some taken for high blood pressure, depression and bladder-control problems (National Institute of Dental and Craniofacial Research, 2024). A systematic review for the World Workshop on Oral Medicine found strong evidence that 56 drugs cause dry mouth or reduced saliva, and moderate evidence for 50 more, across most body systems (Wolff et al., 2017).
Health conditions and cancer treatment
Sjögren’s disease, HIV/AIDS and diabetes can all cause dry mouth, as can radiation therapy to the head and neck, chemotherapy and nerve damage from a head or neck injury (National Institute of Dental and Craniofacial Research, 2024). If you have diabetes, our guide to how oral health affects your body covers the two-way link with gum disease.
Caffeine, alcohol and tobacco
Caffeine, alcohol and tobacco can all dry out the mouth (National Institute of Dental and Craniofacial Research, 2024). If coffee is a daily habit, see how coffee affects your teeth.
Age
Dry mouth is more common in studies of older adults (Agostini et al., 2018), who are also more likely to take several medicines. The guide to how aging affects your teeth and gums covers other changes to watch for.
Why does dry mouth cause cavities?
Without enough saliva, acids linger, food stays on the teeth, and enamel loses its main source of repair minerals. An American Dental Association (ADA) expert panel noted that long-term dry mouth significantly increases the risk of tooth decay, enamel demineralization, tooth sensitivity and candidiasis, a fungal infection of the mouth (Plemons et al., 2014).
Saliva flow almost stops during sleep, so its protection is lost overnight, which is why brushing just before bed matters most (Dawes, 2008). Dry mouth can also make bad breath worse (National Institute of Dental and Craniofacial Research, 2024). If you sleep with your mouth open, see whether mouth taping is good for your teeth.
How can you make more saliva?
Chew sugar-free gum or suck sugar-free candies
Chewing sugar-free gum or sucking sugar-free candies stimulates saliva flow (Dawes, 2008), and the National Institute of Dental and Craniofacial Research suggests citrus, cinnamon or mint flavors (National Institute of Dental and Craniofacial Research, 2024). A Cochrane review found that chewing gum increases saliva production in most people whose glands still work, and that people often prefer it, although it wasn’t shown to be better or worse than saliva substitutes (Furness et al., 2011). Sugar-free gum may also modestly reduce cavities (Newton et al., 2020).
Many sugar-free gums use xylitol. Evidence that xylitol prevents cavities better than other sugar substitutes is weak (Riley et al., 2015), and a 2024 study linked higher blood levels of xylitol with heart attacks and strokes in people undergoing heart tests, an association that needs further study (Witkowski et al., 2024). More in is chewing gum good for your teeth.
Sip water through the day
Water won’t replace saliva’s proteins and minerals, but it keeps the mouth moist. The National Institute of Dental and Craniofacial Research suggests drinking water regularly through the day for dry mouth (National Institute of Dental and Craniofacial Research, 2024).
Use a humidifier at night
A humidifier adds moisture to the air, which can help if dryness is worst at night or first thing in the morning (National Institute of Dental and Craniofacial Research, 2024).
Cut back on caffeine, alcohol and tobacco
Limiting coffee, tea and caffeinated sodas, and avoiding alcohol and tobacco, removes common triggers (National Institute of Dental and Craniofacial Research, 2024).
What treatments can a dentist or doctor offer?
Diagnosis starts with a careful history and a thorough mouth exam, and the main treatment options are saliva stimulants, topical agents, saliva substitutes and prescription medicines that boost saliva (Villa et al., 2015). The ADA panel recommends a step-by-step approach: a detailed health and medication history to find the cause, measuring saliva flow, and teamwork with your doctor (Plemons et al., 2014).
- Reviewing your medicines. Swapping or stopping a drug that causes dryness, when that’s safe, is a first-line strategy (Wolff et al., 2017). Never stop a prescribed medicine without talking to your doctor.
- Saliva substitutes. Sprays, gels and rinses can ease the feeling of dryness, although a Cochrane review found no strong evidence that any one product works well. One spray outperformed another by about 2 points on a 10-point dryness scale (Furness et al., 2011).
- Prescription saliva stimulants. Medicines that stimulate the salivary glands can help some people whose glands still work (Plemons et al., 2014; Wolff et al., 2017).
- Extra fluoride. Topical fluoride from your dentist helps protect teeth when saliva can’t (Plemons et al., 2014). The guide to fluoride explains the options.
Does oil pulling help dry mouth?
There’s no good evidence that it does. The ADA does not recommend oil pulling (American Dental Association, n.d.). A 2024 review of trials comparing oil pulling with mouthwashes measured plaque, gum inflammation and bacteria over 7 to 45 days, not dry mouth, and rated that evidence very low certainty (Jong et al., 2024).
What it means for you
If your mouth feels dry now and then
Sip water, chew sugar-free gum after meals, and notice whether coffee, alcohol or a stuffy nose at night is the trigger (National Institute of Dental and Craniofacial Research, 2024). Keep brushing twice a day with fluoride toothpaste; our daily dental hygiene routine covers the basics.
If you take medicines that dry your mouth
Tell both your doctor and your dentist. Your doctor may be able to change the dose or the drug (Wolff et al., 2017), and your dentist can watch for early decay and add fluoride (Plemons et al., 2014).
Questions to ask your dentist
- Do my teeth or gums show any signs of damage from dry mouth?
- Could one of my medicines be the cause?
- Would extra fluoride, a saliva substitute or a prescription stimulant help me?
- How often should I come in, given my higher risk of cavities?
When to see a dentist
Book a dental visit if:
- Your mouth feels dry most of the time, or dryness keeps you awake.
- You have trouble chewing, swallowing or speaking, or a burning feeling in your mouth.
- You notice mouth sores, cracked lips or white patches that could be a fungal infection.
- You’re getting new cavities even though you brush and clean between your teeth.
These are common symptoms and effects of dry mouth (National Institute of Dental and Craniofacial Research, 2024). For severe pain or swelling, see what to do in a dental emergency.
The bottom line
Saliva is one of your teeth’s main defenses: it cleans, buffers acid and supplies the minerals that repair early damage. Dry mouth affects about one in five people, often because of medicines, and raises the risk of cavities and infections. Water, sugar-free gum, a humidifier and less caffeine and alcohol can help, and a dentist or doctor can review your medicines, add fluoride and suggest saliva substitutes or stimulants.
References
Agostini BA, Cericato GO, Silveira ERD, Nascimento GG, Costa FDS, Thomson WM, et al. (2018). How common is dry mouth? Systematic review and meta-regression analysis of prevalence estimates. Brazilian Dental Journal, 29(6), 606–618. https://doi.org/10.1590/0103-6440201802302
American Dental Association. (n.d.). Oil pulling. MouthHealthy. https://www.mouthhealthy.org/all-topics-a-z/oil-pulling
Dawes C. (2008). Salivary flow patterns and the health of hard and soft oral tissues. Journal of the American Dental Association, 139(Suppl), 18S–24S. https://doi.org/10.14219/jada.archive.2008.0351
Dawes C, Pedersen AML, Villa A, Ekström J, Proctor GB, Vissink A, et al. (2015). The functions of human saliva: A review sponsored by the World Workshop on Oral Medicine VI. Archives of Oral Biology, 60(6), 863–874. https://doi.org/10.1016/j.archoralbio.2015.03.004
Featherstone JDB. (2008). Dental caries: A dynamic disease process. Australian Dental Journal, 53(3), 286–291. https://doi.org/10.1111/j.1834-7819.2008.00064.x
Furness S, Worthington HV, Bryan G, Birchenough S, McMillan R. (2011). Interventions for the management of dry mouth: Topical therapies. Cochrane Database of Systematic Reviews, 2011(12), CD008934. https://doi.org/10.1002/14651858.CD008934.pub2
Jong FJX, Ooi DJ, Teoh SL. (2024). The effect of oil pulling in comparison with chlorhexidine and other mouthwash interventions in promoting oral health: A systematic review and meta-analysis. International Journal of Dental Hygiene, 22(1), 78–94. https://doi.org/10.1111/idh.12725
Lenander-Lumikari M, Loimaranta V. (2000). Saliva and dental caries. Advances in Dental Research, 14, 40–47. https://doi.org/10.1177/08959374000140010601
National Institute of Dental and Craniofacial Research. (2024). Dry mouth. https://www.nidcr.nih.gov/health-info/dry-mouth
Newton JT, Awojobi O, Nasseripour M, Warburton F, Di Giorgio S, Gallagher JE, et al. (2020). A systematic review and meta-analysis of the role of sugar-free chewing gum in dental caries. JDR Clinical & Translational Research, 5(3), 214–223. https://doi.org/10.1177/2380084419887178
Plemons JM, Al-Hashimi I, Marek CL; American Dental Association Council on Scientific Affairs. (2014). Managing xerostomia and salivary gland hypofunction: Executive summary of a report from the American Dental Association Council on Scientific Affairs. Journal of the American Dental Association, 145(8), 867–873. https://doi.org/10.14219/jada.2014.44
Riley P, Moore D, Ahmed F, Sharif MO, Worthington HV. (2015). Xylitol-containing products for preventing dental caries in children and adults. Cochrane Database of Systematic Reviews, 2015(3), CD010743. https://doi.org/10.1002/14651858.CD010743.pub2
Villa A, Connell CL, Abati S. (2015). Diagnosis and management of xerostomia and hyposalivation. Therapeutics and Clinical Risk Management, 11, 45–51. https://doi.org/10.2147/TCRM.S76282
Witkowski M, Nemet I, Li XS, Wilcox J, Ferrell M, Alamri H, et al. (2024). Xylitol is prothrombotic and associated with cardiovascular risk. European Heart Journal, 45(27), 2439–2452. https://doi.org/10.1093/eurheartj/ehae244
Wolff A, Joshi RK, Ekström J, Aframian D, Pedersen AML, Proctor G, et al. (2017). A guide to medications inducing salivary gland dysfunction, xerostomia, and subjective sialorrhea: A systematic review sponsored by the World Workshop on Oral Medicine VI. Drugs in R&D, 17(1), 1–28. https://doi.org/10.1007/s40268-016-0153-9
References checked October 2026 · Editorial policy · Report a correction
Discover more from HappyTeeth.Care
One email a month with new guides and one study, explained. Join and get a free printable dental emergency card. No spam, unsubscribe any time.
