Many people associate tooth decay and periodontal disease with too much candy and not enough brushing and flossing. If only it were that simple. While it’s true that food and personal oral hygiene have a role in oral health, there are many other things that can affect the health of the mouth, including medical conditions such as diabetes and, perhaps ironically, some medicines and medical therapies. This article describes some of the more common oral side effects of medical conditions, medicines, and treatments and what you can do to either head off such side effects or keep your mouth healthy and comfortable in spite of them.
A common side effect of many prescription medicines is xerostomia, or dry mouth. Hundreds of drugs can cause dry mouth, although some are much more likely to than others. Drugs that commonly cause oral dryness include antihistamines, antidepressants (particularly the class known as tricyclic antidepressants), and medicines for high blood pressure. Other possible causes of dry mouth include prolonged high blood glucose, the medical condition Sjögren syndrome, radiation therapy (discussed later in this article), neurological disorders such as Parkinson disease, and dehydration.
Dry mouth is not just uncomfortable, but it can also make food taste funny, affect your ability to speak, and interfere with denture fit, leading to chafing and irritation where the denture touches the mouth tissues. Dry mouth also raises the risk of tooth decay, periodontal disease, and other oral infections, because the lack of saliva allows harmful bacteria to proliferate in the mouth.
Given the discomfort and possible consequences of dry mouth, it’s worth bringing this symptom to your doctor’s attention to determine the cause and whether anything can be done about it. There are also steps you can take on your own to keep your mouth moister and more comfortable and lower your risk of oral health problems. The following may help:
- Sip plain water throughout the day. Tap water is preferable to bottled water since it contains fluoride, which helps prevent against tooth decay.
- Experiment with dry mouth products such as saliva replacements or oral lubricating gel.
- Suck on ice chips or mints sweetened with xylitol, a type of low-carbohydrate sweetener known as a sugar alcohol that has been shown to help prevent cavities when used regularly.
- Choose foods that are moist and soft over foods with rough textures.
- Practice scrupulous oral hygiene: Brush your teeth with a soft toothbrush after meals and use a tongue scraper and floss at least once a day.
- Don’t use mouthwashes that contain alcohol.
- Avoid tobacco and alcohol. Both are drying to the mouth tissues.
Yeast, or Candida albicans, is present in many people’s mouths, but its growth is normally held in check by “good” bacteria. A yeast infection, or uncontrolled growth, occurs when there is a change in mouth chemistry. Such a change can be the result of uncontrolled diabetes, infection with HIV, dry mouth (from any cause), or use of antibiotics, chemotherapy, or drugs that suppress the immune system. Pregnancy, use of birth control pills, and ill-fitting dentures have also been associated with oral yeast infections.
An oral yeast infection, sometimes called oral candidiasis or oral thrush, typically causes whitish or yellowish spots or a film in the mouth. If these spots are brushed or scraped off, they reveal bright red, tender tissue that may bleed slightly. A yeast infection may also be located in the corners of the mouth. It may cause the mouth to feel dry and may or may not be painful. If it is painful, it can be very difficult to maintain normal oral hygiene routines.
Treatment of an oral yeast infection generally requires antifungal medicine and correction of the underlying cause, if possible. In the case of diabetes, that means taking steps to bring blood sugar levels into target range. (Lowering blood sugar should also lower the amount of glucose in the saliva and effectively cut off the yeast’s food supply.) Antifungal medicine may be taken in the form of lozenges that are sucked or a liquid that is swished in the mouth then swallowed. Denture wearers may be instructed to remove their dentures at night and soak them in a cleansing solution overnight.
Because antifungal medicines have a bitter taste, most oral preparations contain large amounts of sugar, which can contribute to both cavities and high blood sugar. There is, however, at least one preparation of the antifungal drug nystatin available in an artificially sweetened version (and there may be others) that may be a better choice for people who have diabetes or recurrent oral yeast infections.
There is some evidence that regularly chewing gum sweetened with xylitol may help to prevent oral yeast infections. Xylitol appears to interfere with the ability of yeast organisms to adhere to the soft tissues of the mouth.
Another potential oral side effect of some drug therapy is overgrowth of the gum tissue, called gingival hyperplasia. The class of antihypertensive drugs known as calcium channel blockers, the immunosuppressant drug cyclosporine, and the antiseizure drug phenytoin are all known to cause this overgrowth of tissue. However, hyperplasia may be prevented or at least minimized while taking these drugs by practicing careful oral hygiene that includes both attentive home care and regular professional cleanings.
When hyperplasia occurs, it can be painful and disfiguring and can interfere with speaking and eating. In some cases, switching to a different drug therapy is a possible solution. If gum overgrowth is severe, surgical removal of the tissue may be necessary. However, the tissue can regrow after surgery if the drug therapy is continued.
People with gum hyperplasia require frequent dentist visits to prevent periodontal disease. As the gums grow, a pocket is created between the tooth and the gum, creating an ideal environment for anaerobic bacteria (bacteria that flourish in the absence of oxygen). A bacterial infection will cause bad breath and will likely raise blood glucose levels as the body tries to fight off the infection.
Proper management of these pockets includes quarterly professional cleaning with an ultrasonic scaler and possibly periodic surgical removal of the overgrowth. Using a sonic toothbrush or a water jet device at home may help to keep teeth and gums as clean as possible between professional cleanings. Water jet devices can remove bacteria up to 6 millimeters under the gum — about 3 millimeters further than a manual toothbrush or floss can reach. However, home care alone is not enough to control bacterial growth when there is gum hyperplasia.
Bleeding upon brushing or flossing is a symptom of gingivitis (inflamed gums) and periodontal disease (infected gums). If you have either of these conditions and also take a drug that thins the blood or prevents clotting, such as aspirin or warfarin, you may notice quite a bit of bleeding during your teeth-cleaning sessions. Some herbal supplements, including garlic and ginkgo biloba, can also have this effect or can magnify the effect of blood thinners and anticoagulants.
Bleeding is usually not a sign that you should brush or floss less; it’s a sign to take your oral home-care routine up a notch and keep regular cleaning appointments with your dental hygienist. In addition, consult your doctor before mixing any drugs with herbal supplements. Increased bleeding is only one of many possible drug-herb interactions.
Effects of radiation therapy
One medical procedure that can have serious oral side effects is radiation therapy of the head and neck. Side effects can include dry mouth, altered sense of taste, mucositis (inflammation of the insides of the cheeks and lips), gum swelling (which can interfere with the fit of dentures), jaw stiffness, and radiation caries (a type of severe tooth decay that is difficult to control). In fact, the risk of oral complications from radiation therapy is so high that a number of health organizations, including the Centers for Disease Control and Prevention, the National Institute of Dental and Craniofacial Research, and the National Cancer Institute, have drawn up guidelines for the prevention and management of oral complications during radiation therapy. Among their recommendations is that people scheduled to undergo radiation of the head or neck have a thorough dental checkup and cleaning and have any dental problems corrected before beginning therapy.
During radiation therapy, a person should be advised to brush the teeth, gums, and tongue with an extra-soft toothbrush and fluoride toothpaste after every meal and at bedtime and to floss daily. Toothbrush bristles can be made even softer by holding the toothbrush under warm water before brushing. A person may also be advised to apply fluoride gel to the teeth using a customized applicator tray for several minutes each day. Using fluoride toothpaste and gel helps prevent tooth decay.
If mouth soreness is a problem, rinsing the mouth with a baking soda and salt solution periodically and eating soft, moist foods can help. Many people are referred to a dietitian during radiation therapy to help with eating issues, and many also see their dentist frequently to have their oral health monitored.
Some of the oral side effects of radiation therapy, such as mucositis, gradually clear up after therapy is concluded, but others linger, suggesting that radiation therapy can have permanent effects on the mouth tissues. People who wear dentures or other mouth appliances may need to have them refitted after radiation. If mouth dryness lingers, daily application of fluoride gel may be needed for life to prevent cavities; self-help measures such as sipping water and possibly using a saliva substitute will also be necessary.
Depression and dental disease
Most people know about the importance of regular brushing and flossing, but what if you just don’t have the energy or motivation to do it? Depression isn’t commonly thought of as a cause or contributor to periodontal disease, but it can be if it affects your ability to care for your teeth and gums. Depression can cause a number of emotional and physical symptoms, including insomnia, lethargy, irritability, forgetfulness, feelings of sadness and hopelessness, decreased or increased appetite, dry mouth, constipation or diarrhea, and loss of motivation to maintain normal routines, such as exercising and practicing oral hygiene.
Simply neglecting oral health care raises the risk of periodontal disease, and the risk rises further if depression is accompanied by an increase in smoking or consumption of alcohol. (Even in the absence of depression, smoking and heavy drinking are detrimental to gum health.)
Depression is a common problem in the United States, and it is even more common among people with diabetes than among the general population. Its onset is often (though not always) associated with life events, such as the death of a loved one or being diagnosed with diabetes, but it can also be a side effect of some prescription drugs, including some used for treating high blood pressure. Since depression frequently goes unnoticed by health-care professionals, it’s often up to the person experiencing depression to ask for help.
Help for depression can come in the form of antidepressant drugs, psychotherapy, or both. If depressive symptoms appear to be drug side effects, switching to another drug may be an option. Self-help measures, such as getting regular exercise, following a healthful diet, and taking steps to control blood sugar level, are important, but they are not enough to treat depression.
If depression (or anything else) is keeping you from attending to your oral hygiene, you may want to schedule more frequent visits with your dental hygienist until your situation changes. In addition to helping you maintain healthy gums and teeth, your hygienist may be able to suggest products or techniques that could make your home care easier or more doable.
Coping with oral side effects
Sometimes the oral side effects of medicines or medical conditions can be alleviated by switching to a different medicine or by treating an underlying condition. But sometimes oral side effects are a tradeoff for life-saving treatment and simply must be dealt with as well as possible. Your dentist and dental hygienist can help you make a plan for maintaining the best oral hygiene possible.
For a healthy mouth, oral cleanliness is imperative, so it’s important to get into the habit of regular brushing and flossing and performing any other home-care procedures recommended by your dental team. Keep scheduled appointments with them, and ask for help if you’re experiencing pain or discomfort.