title: Clinical and histologic effects of facial skin rejuvenation with pulsed- and continuous-wave flash-scanned CO(2) lasers.
abstract: OBJECTIVE
  The reader is presumed to have some understanding of the use of lasers in skin resurfacing. After studying the article, the participant should be able to: Physicians may earn 1 hour of Category 1 CME credit by successfully completing the examination based on material covered in this article. The examination begins on page 409.
  
  
  BACKGROUND
  The selection of the ideal laser for facial resurfacing is debatable.
  
  
  OBJECTIVE
  The purpose of the study was to determine whether any clinical and histologic differences existed in short- and long-term results after treatment with the Coherent UltraPulse 5000G laser (a pulsed laser; PL) and the Sharplan Silk Touch laser (a continuous-wave laser [CWL] with a flash scanner).
  
  
  METHODS
  Eight patients underwent facial resurfacing treatment on different areas. In each case, one side was treated with the PL and the other with the CWL. The condition of the patients and the treated tissue were monitored periodically after treatment. Histologic assessment of punch biopsies was performed 3 months and 1 year after treatment with hematoxylin-eosin, Masson trichromic, and Verhoeff's stains.
  
  
  RESULTS
  The areas treated with the PL achieved earlier epithelialization with a good appearance. Longer-lasting erythema was observed on the side treated with the CWL. On a histologic level, although the PL-treated tissue epithelialized more quickly, at 3 months and 1 year the collagen was better compacted and better aligned in the CWL-treated tissue, and the macroscopic appearance of the CWL-treated areas was more enhanced.
  
  
  CONCLUSIONS
  The more active vascularization seen in the CWL-treated tissue, associated with the longer-lasting erythema and possibly greater collateral thermal injury, is possibly the reason for the better collagenization and remodeling of collagen and elastin fibers as compared with the results with the PL-treated tissue. This may explain the longer effect associated with CWL treatment. The clinician would do well to bear in mind the histologic findings as well as the macroscopic clinical results when assessing the long-term effects of laser skin resurfacing. (Aesthetic Surg J 2001;21:399-411.).
authors.affiliation: Instituto Médico Vilafortuny, Antoni de Gibernat Foundation, Cambrils, Spain.
authors.forename: M A
authors.initials: MA
authors.lastname: Trelles
authors.forename: L
authors.initials: L
authors.lastname: Pardo
authors.forename: O
authors.initials: O
authors.lastname: Trelles
authors.forename: M
authors.initials: M
authors.lastname: Velez
authors.forename: L
authors.initials: L
authors.lastname: García-Solana
authors.forename: J
authors.initials: J
authors.lastname: Rigau
authors.forename: T J
authors.initials: TJ
authors.lastname: Chamorro