Best Answer: People have always argued what the best oil out there is. And most people either go for royal purple, castrol, and mobil 1. I personally choose Mobil 1, but the choice is really opinion based.
The sores may occur singly or in groups and vary from about 1/8 inch to 1 -1/4 inch in diameter. The sore may be painful for three or four days, but complete healing usually takes ten to fifteen days. Canker sores may recur many times each year. Causes: No one knows what causes canker sores. They may be caused by a virus, may be a form of allergic reaction or may result from an auto-immune condition (meaning that the body has developed an immune reaction against its own tissue).
Stress on the tissues or any type of injury in the mouth can cause canker sores. Since the sores are actually tiny ulcers, they can be caused by any kind of hard brushing or eating something that can cause bruises or lead to tissue inflammation in the mouth.