This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Radiology
The best method to reduce radiation caries is application of 
Select and explain. 
A. 0.5% neutral sodium fluoride gel, B. 1% neutral sodium fluoride gel, C. 0.5% stannous fluoride gel, D. 1% stannous fluoride gel
B: 1% neutral sodium fluoride gel
Answer: B: 1% neutral sodium fluoride gel 
Explanation: The best method to reduce radiation caries is daily application of a viscous topical 1% neutral sodium fluoride gel in custom-made applicator trays. The best results are achieved from a combination of restorative dental procedures, excellent oral hygiene, a diet restricted in cariogenic foods, and topical applications of sodium fluoride. Patient cooperation in maintaining oral hygiene is extremely important because radiation caries is a lifelong threat. Teeth with gross caries or periodontal involvement are often extracted before irradiation.
Key Concept:
The best method to reduce radiation caries is daily application of a viscous topical 1% neutral sodium fluoride gel in custom-made applicator trays.
White and Pharoah's Oral Radiology Principles and Interpretation 8th edition