This study evaluated the efficacy of bioadhesive hydrogel patches, made of a pharmaceutical grade cellulose derivative, in the control of pain and as an aid to healing of aphthous ulceration. Patients kept a twice daily ulcer diary to record their pain level on a visual analogue scale. The sensitivity of the test ulcer was assessed by a challenge with pure orange juice as a stimulant before and after application of the patch by the patient. A significant reduction in stimulated pain was recorded following application of the patches to the ulcers (P < 0.01). The patches were found to adhere longer to large ulcers in the early stages of ulceration, when they achieved their maximum protective and pain-attenuating effects. The ulcer size was recorded daily by the patient and patients claimed a reduction in healing time following patch therapy.