IMPORTANT: In issues of oral health and dental care you should ensure your treatment, care, and support is provided by qualified and experienced health professionals. Check the register of the New Zealand Medical Council for Oral and Maxillofacial Surgeons (OMS) (Click here) and the register of the Dental Council of New Zealand for dentists, and prosthodontists.(Click here) Ensure the right health professional with the rights skills, and expertise is providing advice and services for your safety, health and well being. Be aware that this advice from the Ministry of Health does not include OMS that are registered with the Dental Council ONLY.

Dental Health after Radiotherapy

A summary of a talk given the Auckland Support Group in October 2015

Dr Kim Gear from Oral Health gave an interesting talk which sparked some animated discussion.

Below is a summary of her points and the issues raised by patients.

Radiotherapy, Kim said, has long term effects and we need to do what we can to minimise them.

Kim's Tips

The tooth is like a house with enamel on the outside, dentine beneath it and the nerve in the centre. A breach in the wall of the house allows bad bugs to infiltrate. Once they are in the dentine they are harder to control. RT makes things worse so the aim is to avoid the breach. How do we do that?

• Identify susceptible teeth before treatment

• Focus on good bugs not bad

• Take care with sugars in the diet

• Take care with what and when we eat

Importance of saliva

Saliva has many aspects. One of them is for storage. Teeth are like bricks stored in saliva. There is a rebuilding process going on all the time. If you put a tooth in a glass of coke it will dissolve but in the mouth teeth are protected by saliva (normally). Saliva also protects from thrush and helps with eating and speaking.

Non-physical use of saliva

Saliva is so powerful that it has cleaning properties. Kim asked her children to donate some saliva. She used it to clean a discoloured kauri table that had been left outside. She compared the cleaning qualities of saliva with those of water and Mr Muscle. Saliva was clearly superior. Divers use saliva to defog their goggles.

Medications affect saliva

Some drugs can prevent neural transmission, i.e. the message to the brain to make saliva. The following meds are implicated in causing a dry mouth

• Antihypertension drugs

• Anxiolytics

• Antihistamines

• Anticholinergics

• Antipsychotics These are called xerogenic drugs. They should be taken at night if possible so the teeth can be remineralised during the day. (Some meds have sugar, for example Nilstat. Use other antifungals.)

How to avoid dental decay

• Don’t graze, as dieticians often tell you during RT. Put meals together. If you eat sugar, eat with rest of meal.

• Careful oral hygiene. Brush twice a day at least with fluoride toothpaste. Neutrafluor 5000 is good but expensive. This is where we need to push for funding.

• Floss daily. Flossing has been criticised in the news recently but kim is a great advocate for flossing. You can also get little brushes to clean between the teeth

• Rinses are not all good. Some will just mask the problem. A strong fluoride mouthwash would be useful, as is chlorhexidine

• Salt and baking soda (50/50, one teaspoonful in a glass of warm water) is wonderful. Salt breaks down thick saliva and baking soda makes the mouth less acidic.

pH level in the mouth

The pH level is a measure of how acidic the mouth is. This is very important because acid causes the breach in the wall of the tooth.

“The pH scale goes from 1 to 14. 1 being the most acidic, 14 being the most alkaline, and 7 being neutral (like most water). A pH of 5.5 is an important pH level for teeth as the teeth begin to dissolve or demineralize at a pH in the mouth below 5.5.” (

So pH 5.5 is when the building blocks come out to rebuild the teeth. Fluoride applied to the teeth get the level up to 4.5.

More points

• Don’t drink filtered water because filters take out the fluoride

• Carbonated water is acidic – pH level way too low. Sip ordinary water

• Some toothpastes have a foaming agent called sodium laurel sulphate. This can sting. Sensodyne Rapid Relief has no SLS but doesn’t have much fluoride.

• Kim is trying to get a fluoride rinse made at the pharmacy at $3 a bottle. If we can have that we can use normal toothpaste.

• Diet needs to be palatable as well as nutritionally complete. Also practical for unwell patients. There is a book called Cooking Solutions by her predecessor David Hay. Next month she will bring photocopies for us.

• Foodstuffs can be deceptive. For example fruit teas can be bad, with a pH of 3.

• has info about acid in food. Tomato sauce, for example, is loaded with sugar.

Secret weapons

• After eating something sweet, wash your mouth with salt and baking soda. It will reduce the acid, but not take the mouth back to what is was.

• Electric toothbrush. Use child’s one if necessary

• Use only a soft toothbrush

• Flick brush up at 45 degree angle

• Most plaque is at base of tooth

• Clean across the tops and don’t forget the backs


• Savacol is the same as chlorhexidine

• Oral 7 products (She said Biotene but Biotene might not have the active ingredients anymore.)

• Alcohol free Periogard

• Use online products like Squigle – fluoride toothpaste with no foaming agent or flavour

• GC Mouth Gel


Kim thinks we should lobby for better provision of services. Outline complications we have faced and expenses we have borne.

Kim advises us NOT to have all teeth extracted out of frustration because this leads to more complications!

Radiotherapy IS justified to kill the cancer. Her aim is to minimise the damage. She thinks medicine and dental care would work together more.

Research into mucositis

Earlier Kim Gear introduced Annie Bestie, who is studying a PhD in Biological Sciences. Her research topic is mucositis. She is investigating whether certain bugs might contribute to it. (Recently Kim has suggested Blis 18 lozenges, a probiotic. Research isn't complete yet but they have given some people relief.)


Diana Ayling

Dental and Oral Care

Before treatment we advise you to review these resources. We know that head and neck cancer patients can have many dental and oral care issues. We provide resources:

Before Treatment

During Treatment

After Treatment