For treating mouth ulcers, you can use topical gels containing generic ingredients like lidocaine or benzocaine, which numb the area to provide quick pain relief. To reduce inflammation and speed up healing, a corticosteroid dental paste containing triamcinolone acetonide is highly effective when applied directly to the sore. Alternatively, an antiseptic gel like chlorhexidine gluconate can help keep the area clean. Apply these gently with a clean finger after meals. Most ulcers heal naturally within one to two weeks. However, if an ulcer lasts longer than three weeks, is unusually large, or causes severe pain, please consult a doctor or dentist for a proper evaluation.