The Impact of Cancer Therapies on Oral Health

Chemotherapy and radiation are essential tools for treating cancer, but these therapies can result in oral health complications. As dental professionals and as family and community members, we often see firsthand how these treatments affect the mouth and overall quality of life. At times, medical teams only focus on managing the cancer itself, leaving cancer patients to deal with any oral complications on their own. Dentists and hygienists can offer support to patients navigating a cancer journey in the form of preventive strategies, compassionate education, and relief.

This issue is personal to me. My father was diagnosed with stage IV pancreatic cancer several years ago. He was a dentist and had many years of clinical dental experience. He had seen side effects of medications that are extensively used with a cancer diagnosis. Seeing my father live through the same treatments, surgeries, and emotions himself enhanced my own perspective of how changes in the mouth can highly affect a person’s quality of life.

So, what are the most common oral side effects associated with cancer therapy and treatment?

Oral Mucositis

Oral mucositis is common and often the most painful side effect of chemotherapy and radiation.¹ It occurs when the delicate lining of the mouth becomes inflamed and ulcerated, leading to red, swollen, and extremely tender tissues. These ulcers can make eating, speaking, and swallowing very difficult, significantly affecting nutrition and quality of life. Due to delayed healing from the medications, these infections can show signs quickly and may not be able to completely heal while a patient is undergoing cancer treatment. There have been cases where patients have had so much pain from their oral mucositis sores that they elected to stop their cancer treatments. Prevention, therefore, is key when it comes to oral mucositis.

Dental professionals can highlight the importance of proper home care to decrease bacteria and the chance of infection.² Soft toothbrushing with quality products is key to prevent trauma and the chance for open sores developing in the mouth, even before chemotherapy starts. Decreasing bacteria and improving any gingival inflammation that is present even before changing the body’s immune response is pivotal to preventing oral mucositis. Patients can also avoid spicy or acidic foods that may irritate tissues during treatment.

Dry Mouth

One of the most frequently reported complications of cancer treatment is xerostomia, or dry mouth.³ Chemotherapy, as well as head and neck radiation, can damage the salivary glands or alter their function. We know that saliva plays a critical role in lubricating the mouth, protecting tissues, buffering acids, and removing bacteria. Without adequate saliva, patients may experience difficulty speaking, chewing, or swallowing.

Managing xerostomia often includes recommending saliva substitutes that are pH neutral; sugar-free, xylitol-containing lozenges or gums; increased water intake; and prescription-strength fluoride with calcium and phosphate to protect teeth. These extra minerals will supplement what is missing from the naturally occurring saliva and help with the remineralization process of teeth. Along with advising patients to stay hydrated, encouraging them to avoid things that dry the oral cavity, like alcohol-containing mouth rinses or caffeine, can also make a significant difference.⁴

Taste Changes

Cancer therapies may also alter taste perception, a condition known as dysgeusia. Many patients report foods tasting metallic, bitter, or simply bland. These changes occur due to damage to taste buds, nerve pathways, or salivary composition.

For patients already struggling to maintain nutrition during treatment, taste changes can make eating even more difficult. If a patient is experiencing taste changes, they can try experimenting with seasonings, especially ones they have never tried before, or try different temperatures of food. Using plastic utensils can minimize metallic taste that can regularly occur with taste changes. Nutrition is an important part of healing, and when favorite nutritious foods taste differently than before, it can negatively affect health. Working closely with a nutritionist is helpful for patients who are experiencing taste changes.

Increased Caries Risk

Because of xerostomia and dietary adjustments during treatment, cancer patients face a significantly higher risk of dental caries.⁵ Without sufficient saliva to neutralize acids and remineralize enamel, tooth surfaces are more vulnerable to decay. Additionally, many patients turn to high-carbohydrate comfort foods or sugary drinks to help with nausea, which only increases the risk of caries.

Preventive measures for patients with or without dry mouth should be a priority. When it comes to caries prevention, individual planning is important, as a patient may have various products or tasks that will feel more doable than others. Some patients may commit to using a prescription-strength fluoride toothpaste or gel every day, while others may only be open to having applications of in-office fluoride varnish every 3 months. Some patients may love the idea of including xylitol in their routines, and some may only want to use povidone iodine one time a month. We as dental professionals can reinforce the importance of simple home care to mechanically remove biofilm and supplement the decrease in saliva, even when patients feel fatigued.

Burning Mouth Syndrome

Some cancer patients experience burning mouth syndrome (BMS),⁶ a condition characterized by chronic burning, tingling, or pain in the mouth without an obvious cause. This may result from nerve damage, xerostomia, or as a side effect of chemotherapy medications. Patients often describe the sensation as similar to scalding from hot food or drink and can occur at any point during the day.

As you can imagine, BMS can negatively affect appetite, nutrition, and quality of life. While no single cure exists at this time, management strategies may include pH-neutral saliva substitutes, topical pain-relief rinses, and collaboration with the oncology team to adjust medications if possible. Providing empathetic listening and reassurance is essential.

Our Role with Our Patients

As dental professionals, we are in a unique position to support patients undergoing cancer therapy. Preventive oral care visits before, during, and after treatment are crucial to reduce complications. During these visits, we can educate patients on their current oral hygiene and talk about things that may happen in the future with their treatment, help with product recommendations for xerostomia, place caries prevention medicaments, screen and monitor for oral mucositis, and be a collaborative provider with oncology teams to provide safe, patient-centered care.

Beyond the clinical side, compassion and empathy are powerful tools. Many patients and their caregivers feel overwhelmed by the sheer number of changes cancer treatment brings. Being a trusted partner in their care not only helps them manage oral side effects but also improves their confidence and overall well-being.

Cancer therapy can profoundly affect oral health, from dry mouth and taste changes to heightened caries risk and burning mouth syndrome. These challenges may seem secondary compared to fighting cancer itself, but they deeply affect daily living, quality of life, and the outcome of the treatment. By staying informed and proactive, dental professionals can help patients navigate these side effects with dignity, comfort, and improved oral health outcomes. Our knowledge and care remind patients that while cancer therapy may change many aspects of their health, they do not have to face these oral challenges alone.

ABOUT THE AUTHOR

Melia Lewis, MEd, RDH, practices at Aspen Heights Dental in Highland, Utah, and is an adjunct professor at Colorado Northwestern Community College. She is cofounder of Hygiene Edge, an online education platform, and owns and operates Acuti Sharpening, a dental hygiene instrument sharpening company.