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).
Canker sores can be very painful! The exact cause of canker sores is not entirely certain, although several different factors including stress, certain spicy/acidic foods, or vitamin deficiencies can be associated with them. They are also associated with some autoimmune or gastrointestinal conditions such as Crohn's disease or celiac disease. Canker sores typically resolve within a week or so, although aggravating factors such as spicy foods or mechanical trauma can make them take longer to heal. The fact that your canker sores have persisted for over 3 weeks is an indication that you should return for evaluation with either your dentist or your oral surgeon.