The normal radiation therapy for head and neck cancer is 10-70Gy. We would like to know if there is any radio protective techniques to minimize the effects of radiation on enamel and dentin.
A critical threshold of ≥60Gy may be linked to direct effects of radiation on tooth structure. Findings suggest that care should be taken during the treatment planning process to limit tooth dose, and when clinically possible to limit tooth dose to less than 60 Gy.
I am suggesting to read an article: http://www.priory.com/den/caries05.htm
It explain
Dental caries following radiation therapy is, like so many other problems, and accumulation of events that creates an ongoing problem. 50+ years ago the thought was that radiation had a direct effect on the teeth thereby altering the structure of enamel and dentin. Consequently the management procedures in the 1950s and 1960s was primarily through the removal of teeth prior to therapeutic radiation. the radiation sources in those days were low-energy sources of radiation such as cobalt which had very little bone sparing affect. With time linear accelerators became more prevalent and it would be difficult today to find low energy sources such as cobalt or anything lower than that still in use for the management of oral cancer.
As dental management Of carries improved the dental profession likewise demonstrated an improved appreciation of the reason for caries in the radiation therapy patient group. Most of the patients who developed "radiation carries" were developing dental caries subsequent to the loss of protective, natural salivary production. With xerostomia the patient seemed to be more susceptible to dental caries oftentimes appearing on surfaces that would normally not be the first risk surfaces (facial Surfaces, lingual surfaces, cervical areas, etc. rather than inter proximal and occlusal caries which may have already been affected in this patient group, the patients needing radiation therapy for oral cancer, given the time in history and the prevalence of caries on inter proximal surfaces and occlusal surfaces prior to the more ubiquitous use of Florida did water). So as we progressed into the 1970s and beyond there was a gained an appreciation that teeth could be retained using daily, lifelong, topical fluoride applications, the use of re-mineralizing solutions and meticulous oral hygiene. The pendulum therefore swung from removal of all teeth to the removal of only those teeth bit were on restore will prior to the radiation treatment.
Perhaps we've seen that pendulum switch again towards the removal of teeth that are nonstrategic and have higher risk of breakdown because of pre-existing dental restorations. We've also seen a greater awareness that carries can be managed through multiple risk assessment which then means that there would be multiple treatment interventions were multiple layers of treatment intervention with each treatment intervention layer providing, perhaps, an improved condition relative to dental caries. Meaning that the risk of dental caries, if high, would require a number of different methods to try to reduce that risk by attacking the risk more aggressively. See the articles by Featherstone and the CAMBRA protocols. If we extrapolate these caries management methods towards the patients who are probably most at risk for dental caries, those patients who are xerostomic and probably the most severe group of xerostomia patients are the radiation therapy patients, the caries management method becomes more clear.
Has the pendulum moved towards an appreciation that a certain Threshold level of radiation could have a physical effect on the surface of the tooth? This certainly has been discussed and it is my perception that there are arguments both pro and con.
Regardless, carries control through aggressive management using multiple interventions seems to be effective in many, but not all, patients. Those of us who have worked in the oral cancer field for decades oftentimes recognize that some patients can manage their caries risk for many many years but then something in their life may change and they can exhibit dramatic, rapid deterioration of their dental health through dental caries. The possibility of lifelong prevention exists but the risk of rapidly progressive caries remains. The multi tiered level approach to the management of this dental caries is likely to include strict oral hygiene methods, fluoride applications, daily fluoride gel of neutral preparations of fluoride, calcium/phosphate remineralizing solutions, xylitol chewing gum, chlorhexidine rinse, baking soda toothpaste, etc. and may even include other method such as the use of iodine or sodium hypochlorite solutions in the brushing of the teeth. It's important to remember that the more levels of prevention that are utilized the lifelong commitment to the use of these methods becomes more and more critical. Said another way compliance is a major factor on the part of the patient.
Dear Mithra
I think John and Steven has covered all aspects as regards the info you need. Now it is your turn to get these into practice :) !
This is a multidisciplinary work. The first thing you have to do is convince the radiotherapists that the preparation has to be started before radiotherapy is started. Your own Dept can design and make the fluoride applicators. Convince the management that these can be produced and marketed at least without any loss to them. Then you may get the Pharmacy Dept to manufacture artificial saliva.
Getting all these done will be the most difficult part.
Anyway this is a very important area and often neglected
Narayanan
I aggree ofcourse with all the above. I would only want to emphasize at the issue of educating the patients of the importance of oral hyegene and training them of how to apply it on an everyday base.
Neutrophil leukocytes enter in oral cavity with complet dentition about 1 million per minut. Why are they completly ignored in dental caries infection development?
- Badges
- Science topic
- Similar topics
- Geoscience
- Asia
- India