Xerostomia and Dental Caries and How To Treat

Xerostomia, or dry mouth, is a common problem associated with the insufficient production of saliva. Although largely overlooked, figures show that one in five adults have xerostomia. This means that 20% of people ages 18-30 and 40% of people older than 50 have this problem[i]. Dry mouth is not a disease, but it could be a symptom of an underlying health condition and it tends to go hand in hand with other dental health problems such as caries. In this post, we explore the link between xerostomia and caries as well as its management.

Can dry mouth contribute to caries?

All factors involved in dental health are connected including dry mouth and caries. Unfortunately, this subject isn’t discussed as frequently as it should considering the wide prevalence of both caries and xerostomia. Evidence shows that patients with xerostomia have significantly more carious lesions than their counterparts without this problem. What’s more, about 70% of those reporting xerostomia have at least one carious lesion compared to 56% general population[ii].

Some medications can decrease the production of saliva i.e. they contribute to xerostomia and thereby increase the risk of dental caries. Reduced salivary flow also lowers buffering of plaque acids thus making teeth vulnerable to bacteria and caries formation. When xerostomia occurs it paves the way to demineralization which happens at a faster rate than re-mineralization.

How does xerostomia contribute to caries?

The relationship between xerostomia, which is caused by many factors, and caries revolves around saliva production. In people with xerostomia production of saliva decreases significantly, which takes its toll on dental health. Perhaps your xerostomia has been caused by your use of certain antihistamines, antidepressants or other medications known to cause xerostomia, or due to dehydration – what matters the most is the risk that you are exposed to until you treat the cause and act to remove the symptoms of dry mouth in time. You see, saliva has many functions including development of dental pellicle, a film that forms on tooth enamel to protect it against mineral loss. In addition, saliva participates in the replenishment of tooth surface minerals like calcium and phosphate. Saliva is also necessary for antibacterial activity that protects your teeth as well.

On the other hand, lack of saliva makes teeth exposed to acidic challenges from beverages and food as well as to acids produced by certain bacteria. The absence of salivary calcium and phosphate doesn’t allow the process of natural re-mineralization to occur[iii] and your teeth aren’t protected anymore. This increases the risk of caries.

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Management tips

Xerostomia is an uncomfortable problem that contributes to various dental health issues such as caries, bad breath, and it makes your gums sensitive too. There are many cases in which xerostomia has been found responsible for the occurrence and development of the symptoms of tooth decay, cavities, gingivitis etc. Because of the existence of these risks that xerostomia easily brings in the patient’s life, its early diagnosis and treatment are of a vital importance. Luckily, there are numerous different treatment methods that you can try and which have been proven beneficial when it comes to the treatment of xerostomia and with that all of the added risks to your oral health. You can manage this problem successfully and, thereby, prevent caries.

The use of MI Paste can be of huge help for caries prevention in persons with xerostomia. MI Paste is a tooth crème that contains CPP-ACP (calcium phosphopeptide-amorphous calcium phosphate) which aids in re-mineralization and caries prevention. Evidence confirms the efficacy of MI Paste for prevention of caries and mouth moistening[iv]. MI paste is a water-based, sugar-free tooth cream that looks a lot like your usual toothpaste. The MI paste is quite easy to be used – all that you have to do is use a pea-sized amount that you will smear over your teeth and let it do its thing for around 3 minutes. No rinse is needed. You can do it by using your fingers – preferably with by using a glove as well, your toothbrush or a cotton swap. The MI paste is known to not only prevent caries and tooth decay effectively but also optimize the acid levels in the oral cavity, reduce tooth sensitivity and remove any spots from your teeth.

Besides MI paste, it is practical to use products and chewing gums containing xylitol, a sugar alcohol with antimicrobial effects. Studies show that xylitol decreases the incidence of caries by increasing salivary flow, improving pH, and lowering concentration of caries-causing bacteria. Xylitol also proves to be effective in decreasing gingival inflammation, managing symptoms of xerostomia, and preventing or managing erosion of teeth[v]. Chewing gums with added xylitol are great to be used by anyone including diabetics because, despite the fact that we are using the term sugar in sugar alcohol to talk about xylitol, xylitol has not shown any changes in the sugar levels so diabetics can feel safe while they use xylitol – of course within the recommended dosage.

Yet another ally in the prevention of caries is fluoride which is found in most toothpaste, but there is also gel as well as a fluoride mouthwash – all designed with one sole purpose – to help you prevent caries the best way that you know how. Fluoride is also found in the drinking water – naturally or added. One study found that application of fluoride gel every second day or weekly combined with fluoride mouthwash use for six weeks inhibited demineralization process and it can prevent xerostomia-related dental caries[vi]. We kindly recommend looking for toothpaste which contains fluoride and even buying a quality fluoride gel just because the topical appliance of fluoride has been found to be the most effective one because you are after all applying fluoride at the site of action.

Other things to do:

  • Limit caffeine intake
  • Avoid mouthwashes that contain alcohol (because it exhibits drying effects) and xylitol because of reasons that we have discussed before
  • Quit smoking and avoid any kind of tobacco use
  • Drink water regularly
  • Consult your doctor about any symptoms that you notice
  • Schedule regular check-ups at the dentist’s office
  • Avoid sugary and acidic foods and drinks
  • Brush your teeth regularly
  • Do not avoid flossing and using mouthwash as a part of your routine oral hygiene
  • Avoid chewing gums as much as possible, they are filled with sugars and only add to the development of tooth decay and cavities, instead, use mouthwash – preferably one that has xylitol added


People with xerostomia are at a higher risk of dental caries because saliva plays a big role in oral health. It is responsible for keeping your mouth lubricated, digesting your food and removing the excess bacteria and plaque off your teeth. When there is less saliva normally produced due to various reasons, a condition is known as xerostomia or dry mouth, you are exposed to a great risk of gingivitis, tooth decay, cavities etc. Fortunately, there are many things you can do to prevent or treat this condition for healthier teeth. Good oral hygiene, proper hydration and avoidance of certain foods and drinks can go a long way for you and your oral health. The choice of toothpaste or mouthwash matters a lot and it’s also necessary to make some lifestyle adjustments. If you have learned anything from today’s article that is the fact that what you need is to buy yourself a quality toothpaste, one that has fluoride added to it, some mouthwash with xylitol included in the ingredients list and even a good MI paste that you can include in your daily oral hygiene routine. Your teeth and gums will thank you for it as you will notice no trace of cavities, gingivitis, periodontal disease or any other common oral health issue in the near future.


[i] Xerostomy, DentAid http://www.dentaid.com/en/xerostomy
[ii] Hipcraft MS, Tan C. Xerostomia: an update for clinicians. Australian Dental Journal 2010 Sep;55(3):238-44. Doi: 10.1111/j.1834-7819.2010.01229.x https://onlinelibrary.wiley.com/doi/full/10.1111/j.1834-7819.2010.01229.x
[iii] Su N, Marek CL, Ching V, et al. Caries prevention for patients with dry mouth. Journal of Canadian Dental Association 2011;77:b85 http://www.miriamgrushka.ca/uploads/thedrymoutharticle.pdf
[iv] Somasundaram P, Vimala N, Mandke LG. Protective potential of casein phosphopeptide amorphous calcium phosphate containing paste on enamel surfaces. Journal of Conservative Dentistry : JCD. 2013;16(2):152-156. doi:10.4103/0972-0707.108199. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3659862/
[v] Nayak PA, Nayak UA, Khandelwal V. The effect of xylitol on dental caries and oral flora. Clinical, Cosmetic and Investigational Dentistry. 2014;6:89-94. doi:10.2147/CCIDE.S55761. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4232036/
[vi] Jansma J, Vissink A, Jongebloed WL, et al. Xerostomia-related dental caries. Nederlands Tijdschrift voor Tandheelkunde 1992 Jun;99(6):225-32 https://www.ncbi.nlm.nih.gov/pubmed/11820137

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