Dental Care During and After Cancer Treatment: A Guide for Townsville Patients

Cancer Treatment and the Mouth

Cancer treatment — whether chemotherapy, radiotherapy, targeted therapy, immunotherapy, or stem cell transplant — commonly affects oral health. The mouth is vulnerable because it is lined by rapidly dividing epithelial cells that are sensitive to cytotoxic agents and radiation, and because the oral microbiome is complex and can become pathogenic when immune function is compromised.

Approximately 40 per cent of patients undergoing standard chemotherapy and up to 80 per cent of those receiving high-dose chemotherapy before stem cell transplant will develop oral mucositis. Among patients receiving radiation to the head and neck, mucositis is nearly universal, and permanent salivary gland damage is common.

Understanding these risks and preparing appropriately makes cancer treatment safer, more tolerable, and more likely to proceed on schedule.

Before Cancer Treatment Starts: The Pre-Treatment Dental Assessment

The most important step any cancer patient can take for their oral health is scheduling a comprehensive dental assessment 4 to 6 weeks before treatment begins. This allows enough time to treat dental disease and allow healing before immune function is suppressed.

What the pre-treatment dental assessment covers

Oral examination and panoramic x-ray (OPG): Identifies all existing decay, gum disease, root infections, problematic wisdom teeth, and poorly fitting restorations or dentures. Problems that would require extraction or other surgical treatment should be identified and addressed before treatment.

Treatment of active dental disease:

• Tooth extractions — any tooth that will require extraction in the near future should be extracted before chemotherapy. A minimum of 2 to 3 weeks is required for socket healing before chemotherapy begins
• Fillings of active cavities
• Scaling and periodontal treatment for gum disease
• Adjustment or replacement of poorly fitting dentures that could cause mucosal trauma

Prophylactic fluoride treatment: High-risk patients (particularly those receiving head and neck radiation) are fitted with custom fluoride trays and prescribed high-strength fluoride for daily use.

Patient education:

• Oral hygiene technique — soft toothbrush, gentle technique
• Mucositis prevention: salt and sodium bicarbonate mouthrinses
• Denture care and removal during sleep
• Nutritional guidance to support oral healing

Coordinating with the oncology team

The pre-treatment dental assessment should be communicated to the patient’s oncologist or radiation oncologist. The dental team and oncology team need to coordinate on:

• Timing of dental procedures relative to treatment start
• Expected immunosuppression periods (nadir dates for chemotherapy cycles)
• Any planned radiation field that may affect salivary glands or jaw bone

Oral Complications During Cancer Treatment

Oral Mucositis

What it is: Oral mucositis is ulceration and inflammation of the oral mucosa — the lining of the cheeks, lips, tongue, gums, palate, and throat — caused by direct cytotoxicity from chemotherapy or radiation.

Severity grading:

• Grade 1: Erythema (redness), soreness
• Grade 2: Patchy ulceration, can eat modified diet
• Grade 3: Confluent ulceration, unable to eat solid food
• Grade 4: Tissue necrosis, life-threatening complications

Prevention strategies with evidence:

• Basic oral care protocol: soft toothbrush, fluoride toothpaste, saline/bicarbonate rinses every 4 hours
• Cryotherapy: Sucking on ice chips during chemotherapy infusion reduces blood flow to the mouth and reduces mucosal exposure to cytotoxic drugs. Effective for agents with short half-lives such as 5-fluorouracil
• Keratinocyte growth factor (palifermin): Approved for patients undergoing high-dose chemotherapy for haematological malignancies. Reduces grade 3–4 mucositis incidence
• Low-level laser therapy (LLLT): Growing evidence supports LLLT for reducing mucositis severity; not universally available in Townsville

Management during mucositis:

• Morphine-based topical gel or systemic opioids for grade 3–4 pain
• Nutritional support — liquid diet, supplemental drinks, nasogastric tube if unable to maintain intake
• Antifungal treatment for concurrent oral candidiasis
• Saline rinses continued throughout

Oral Infections

Chemotherapy-induced immunosuppression reduces the ability to fight oral infections. Two main organisms cause the majority of treatment-related oral infections:

Candida (thrush): Oral candidiasis (white plaques on tongue and mucosa) is common during chemotherapy. Prophylactic antifungal medication (fluconazole or nystatin suspension) is often prescribed during predictable immunosuppression periods. Good oral hygiene and denture cleansing (removing dentures at night, soaking in antifungal solution) reduce risk.

Herpes simplex virus (HSV) reactivation: Patients with prior HSV exposure (a large proportion of adults) can experience severe oral HSV reactivation during immunosuppression. Prophylactic antiviral medication (acyclovir or valacyclovir) is commonly used.

Bacterial infections: Dental and periodontal infections that were stable before treatment may become acute during chemotherapy. Untreated dental disease present at the start of treatment becomes a potential source of systemic sepsis during neutropenia (low white cell count).

Xerostomia (Dry Mouth)

From chemotherapy: Salivary gland function is affected by many chemotherapy agents, causing temporary dry mouth. This typically resolves within weeks to months after treatment ends.

From head and neck radiotherapy: Radiation to the head and neck region commonly affects the parotid, submandibular, and sublingual salivary glands. When major salivary glands are in the radiation field, permanent xerostomia is common. Modern techniques including intensity-modulated radiotherapy (IMRT) attempt to spare salivary gland tissue, but significant dry mouth remains a frequent long-term side effect.

Permanent xerostomia dramatically increases the risk of radiation caries — rapid, aggressive tooth decay that progresses around the cervical margins of teeth and at root surfaces. Without saliva’s buffering and remineralisation functions, patients can lose multiple teeth within 1 to 2 years of head and neck radiation if oral care is not meticulous.

Management of xerostomia:

• Frequent water sips throughout the day
• Saliva substitutes: sprays (Biotene), lozenges, gels
• Pilocarpine (Salagen) — muscarinic agonist that stimulates residual salivary function; effective for some patients
• Sugarfree chewing gum — stimulates salivary flow in patients with residual gland function
• Avoid alcohol and caffeine (drying effect)
• Avoid alcohol-based mouthwashes

Trismus (Jaw Stiffness)

Patients receiving radiation to the head and neck region may develop trismus — reduced mouth opening — due to radiation-induced fibrosis of the masticatory muscles and temporomandibular joint structures. Trismus can develop during or months after radiotherapy completion.

Prevention involves jaw-opening exercises commencing during radiotherapy — typically three sets of 20 repetitions of maximum opening daily. A TheraBite device or wooden tongue depressors (placed stacked between the teeth) can facilitate progressive stretching. Once established, trismus is difficult to reverse.

Osteoradionecrosis of the Jaw (ORN)

When the jawbone receives a high radiation dose (above approximately 60 Gy), it can undergo avascular necrosis — the bone’s blood supply is destroyed and the bone dies. Exposed, non-healing bone in the oral cavity is the characteristic presentation. ORN is a serious, potentially permanent complication that is extremely difficult to treat.

Risk reduction:

• Avoid tooth extractions in the high-dose radiation field after treatment — plan all necessary extractions before radiotherapy
• If extraction after radiation is unavoidable, hyperbaric oxygen therapy (HBO) before and after the procedure may reduce ORN risk
• Maintain excellent oral hygiene to prevent dental disease that could necessitate extraction

Townsville patients who require dental extractions years after head and neck radiation should be managed by an oral and maxillofacial surgeon with experience in this area, not by a general dental clinic.

Long-Term Oral Health After Cancer Treatment

Regular dental monitoring

Cancer patients who have completed treatment require more frequent dental monitoring than the general population, particularly those with radiation-induced xerostomia. Three-monthly preventive visits (rather than 6-monthly) with professional fluoride application are typically recommended for head and neck cancer patients.

Daily fluoride for radiation patients

Daily use of high-fluoride prescription toothpaste (5,000 ppm) or custom fluoride tray applications is a cornerstone of dental care for patients with radiation-induced dry mouth. Over-the-counter fluoride (1,000–1,500 ppm) is insufficient protection for this high-risk group. Prescription toothpaste requires a dentist’s prescription but significantly reduces radiation caries risk.

Implants and dentures after head and neck radiation

Dental implant placement in previously irradiated bone carries a substantially higher risk of failure and osteoradionecrosis than implant placement in non-irradiated bone. In patients who received radiation doses above 50 Gy to the implant site, specialist surgical assessment is required. Hyperbaric oxygen before and after implant placement is used in some centres.

Dentures in patients with radiation-induced mucositis and dry mouth require careful management — ill-fitting dentures become intolerable quickly and can cause mucosal trauma that increases infection risk. Regular denture review and adjustment is important.

Getting Support in Townsville

The Townsville University Hospital and Icon Cancer Centre Townsville provide oncology services and can coordinate with dental services for patients undergoing cancer treatment. Patients commencing treatment should ask their oncologist for a referral to the Townsville Hospital Oral Health Service for pre-treatment dental assessment if they do not have a regular dentist.

For patients experiencing dental side effects during or after treatment, a referral from their GP or oncologist to a general dentist with experience in medically complex patients or to the hospital dental service is the appropriate pathway.

For related guides see the dry mouth Townsville guide, the dental implants with bone loss guide, and the diabetic dental care guide.