Objective: Recurrent aphthous ulceration is the most common oral mucosal lesion and may be associated with many systemic diseases. Topical corticosteroids are used frequently for recurrent aphthous ulceration; however, the number of high-quality clinical experiments available is insufficient, and no reports exist on the blood level of corticosteroids after topical usage in the oral mucosa. The objective was to determine the efficacy and safety of dexamethasone ointment in the treatment of recurrent aphthous ulceration and detect serum dexamethasone concentrations in the patients.

Methods: A randomized, double-blinded, placebo-controlled, parallel, multicenter clinical trial was conducted in 5 centers to compare the efficacy and safety of dexamethasone ointment with placebo. There were 810 patients with minor recurrent aphthous ulcerations screened for study eligibility, and 240 patients were enrolled at 5 centers from March 1, 2009 to April 30, 2010; 120 were assigned randomly to the treatment group and 120 to a control group. Patients were instructed to apply the given agent to the identified ulcer 3 times a day (after meals) for 5 days. The size, pain level, healing ratio, and average duration of ulcers and the safety of the agents were evaluated. The serum concentration of dexamethasone was detected using a high-performance liquid chromatography/mass spectrometry assay.

Results: The results showed that baseline characteristics were similar (P>.5). At day 6 ± 2 after treatment, there was significant difference in the variation of ulcer size between the treatment group (7.167 ± 6.3415 mm(2)) and the control group (4.346 ± 7.0666 mm(2); P = .000); and in the variation of pain level between the treatment group (5.623 ± 1.9570) and the control group (4.940 ± 2.2449; P = .001). The healing ratio was 83.33% in the treatment group and 54.70% in the control group (P = .000). No severe adverse reactions were observed. No serum dexamethasone was detected before or after the use of the agents (<0.502 ng/mL).

Conclusion: Dexamethasone ointment was efficient in the treatment of recurrent aphthous ulceration and was safe as evaluated using clinical assessment and serum level detection.