Abstract: Objective: To compare the clinical short-term effects of Nd:YAG laser and CO₂ laser in the treatment of minor aphthous ulcer (MiRAU). Methods: Sixty-eight cases of clinically diagnosed minor aphthous ulcer (MiRAU) patients were randomly divided into 2 groups, namely, the Nd:YAG laser treatment group (Nd:YAG laser group) and CO₂ laser treatment group (CO₂ laser group) with 34 cases in each group.The treatment period was 3-5 days. By the method of VAS and DP classification, the short-term curative effect of two groups was evaluated and compared. Results: In the first three days after laser treatment, the pain reduction index value of two groups was recorded, respectively. Index value of the Nd: YAG laser was: (3.27±0.24), (4.23±0.26) and (5.60±0.27), which was significantly higher than that of the CO₂ laser group with the index value of (2.56±0.27), (3.40±0.30) and (4.20±0.28) (P<0.05). After the laser treatment,Ulcer healing time was(4.07±0.82)days in Nd:YAG laser group, which was significantly shortened than the(5.12±0.26)days in CO₂ laser group (P<0.05). The total effective rate was 100.0% in Nd:YAG laser group and 90.0% in CO₂ laser group. Nd: YAG laser group of patients showed no obvious reaction. And CO₂ laser group has 6 cases of nervous pain, and 7 cases sensitive to smell. Conclusion: Significant effects on the treatment of MiRAU was observed between Nd:YAG laser and CO₂ laser group. By comparison, Nd:YAG laser has more advantages in shortening the healing time and relieving pain.

Key words: Recurrent aphthous ulcer , Nd:YAG laser, CO₂ laser, Curative effect