How do you get rid of a canker sore by tomorrow? what cream, ointment, etc.. truly works?

Different things.: For canker sores or aphthous ulcers, dissolving a common antibiotic like tetracycline in water and swishing it in the mouth a few times a day has shown to help. Topical steroid (kenalog (triamcinolone) in orabase) can also help, but both require prescriptions. Zinc lozenges, vitamin c are known to possibly help (no good studies though).

Mouth bandaid: Your canker sore would heal quickly if you could keep your tongue off of it. Just like a cut on your finger that feels better with a bandaid on it a protective coating on the canker relieves acute pain & by keeping your probing tongue away promotes healing. Try kanka, a drop of tincture of benzoin or even one of milk of magnesia (magnesium hydroxide). All work by creating a temporary mouth bandaid.

Ointments: There are several prescription ointments for canker sores that sooth and heal. There is also an ointment called kenalog (triamcinolone) in orabase that acts like an oral bandage to soothe and protect. You should consult your dentist.