Abstract: Objective To evaluate and compare the effectiveness of pulsed dye laser(PDL)and the long-pulsed Nd:YAG laser in the treatment of fresh scars. Methods Patients with fresh scars were involved for a comparative randomized split-scar trial. Each scar was divided at the midline into two fields. One half received treatment by pulsed dye laser (Vbeam, Candela Corp.) with a 7 mm spot size at 0.45 ms with 6~9 J/cm2and a 20 ms spray duration with a 20 ms delay. The other half was treated by Nd:YAG (GentleYAG, Candela Corp.) with a 3 mm spot size at 10 ms with 150~180 J/cm2. Patients received 3 laser treatment sessions at one month interval. The scars were evaluated with Vancouver scar scale (VSS) 2 months after treatment. Results Twenty-one patients with average 3.4-week scars were involved. Two months after last treatment, final total VSS analysis revealed significant decline of both PDL and long-pulsed Nd:YAG laser group after treatment (P<0.05), but no statistical difference between the 2 groups (P>0.05). However, the emphasis was different. The PDL sites advantaged in the improvement of vascularity and thickness of scar, whereas Nd:YAG in pliability. Conclusion Both 2 kinds of lasers could improve the appearance of fresh scars but emphasize differently.

Key words: Fresh scars, Pulsed dye laser, Long-pulsed Nd:YAG laser