Long-term results after CO2 laser skin resurfacing: a comparison of scanned and pulsed systems

Background: New laser technology permits the use of high-energy pulsed and continuous-wave carbon dioxide (CO2 ) lasers with flashscanners to treat rhytides. Objective: We compared the efficacy and side effects of the two leading CO2 lasers used in skin resurfacing. Methods: A total of 28 patients with facial rhytides were treated with either the UltraPulse or SilkTouch laser systems; in five additional patients, contralateral cosmetic units were treated with one system or the other in a direct comparison of the lasers. Results: We compared photographs taken before and after treatment, and a lessening of facial wrinkling was noted in all subjects. In some subjects improvement was confirmed by optical profilometry methods. Biopsy specimens in representative patients showed that immediate thermal damage was limited to 180 μm. Long-term postoperative specimens showed changes in the papillary dermis consistent with new collagen deposition and reduction of pretreatment solar elastosis. Posttreatment facial erythema was noted in half the patients for up to 2 months; transient hyperpigmentation was observed in one third of the treated areas. Conclusion: Although the SilkTouch system produced more immediate thermal damage, there were no significant differences in efficacy or adverse effects between the lasers. Our results suggest that both laser systems, used with appropriate settings, are capable of safely smoothing the skin surface. (J Am Acad Dermatol 1997;37:709-18.)