A dental abscess is a painful dental infection that usually starts suddenly and becomes more intense over time. The pain may radiate to the jawbone, ear, or neck in some cases. The following signs and symptoms characterise a dental abscess: The affected area is the one that hurts when bitten or touched. Gums that are swollen and red Temperature sensitivities to hot and cold foods and liquids There is a bad taste and smell in the mouth. Swollen lymph nodes An inability to open the mouth Having trouble swallowing A general feeling of unwellness