I have a canker sore[that i think formed by biting the lip] which tend to came back but it don't appear like the first time.... how can i treat it ?

Apthous ulcer: Sounds like recurrent apthous ulcer. These are usually caused by trauma or stress. Try abreva over the counter. If this doesn't work your dentist needs to see you to make a proper diagnosis. The med i prescribe for this or any traumatic lesion, including burns, is called kenalog (triamcinolone) in orabase 0.1%. This med will form a protective cover over the lesion to heal faster and it also numbs the area.

Canker or Cold sore?: Cankers (recurrent aphthous ulcers) are an "auto-immune" type reaction to trauma/stress (such as biting your lip). They occur on the loose membranes of your lips, cheeks and floor of the mouth. Your dentist can treat with prednisone, laser or chemicals to cut pain. Cold sores are hsv. Abreva helps those some, but most need doc rx. Both go away without treatment in 10-14 days (pain only 3-5 days).

Symptoms only: Recurrent apthous ulcers last 7-14 days no matter what. But you can decrease the pain the absolute best product I have found is kanka, an otc little brown bottle of relief! it contains benzocaine, a topical anesthetic, and benzoin, a coating agent that is safe, effective, and can be used as often as you want. Try it. You'll like it!