title: Ablation of human nail by pulsed lasers.
abstract: OBJECTIVE
  The hard and resistant structure of the nail plate forms a natural barrier that limits the penetration of topical drugs. To overcome this barrier, the use of pulsed laser systems has been suggested. The purpose of this study was to evaluate the effect of four laser systems on nail plate ablation rates, ablation efficiencies, and subsequent craters morphology.
  
  
  METHODS
  Solid state Er:YAG (2.94 microns, 250 microseconds), a Ho:YSGG (2.08 microns, 250 microseconds), a XeC1 Excimer (308 nm, 15 ns), and a novel solid-state ultrashort pulse laser (1.05 microns, 350 fs) were used. Ablation rates, surface morphology, and extent of collateral damage were evaluated using light and electron microscopy.
  
  
  RESULTS
  Best ablation efficiencies were demonstrated with the ultrashort pulsed laser (1 micron/mJ), whereas maximum material removal per pulse was obtained with the Er:YAG laser (80 microns/ pulse). Scanning electron microscopy showed cracking damage with both Ho:YSGG and Er:YAG. XeC1 and the ultrashort pulse system left tissue surfaces free of cracks or thermal damage.
  
  
  CONCLUSIONS
  With its minimal acoustical and mechanical impact, high efficiency, and negligible collateral damage, the ultrashort pulse laser at 3 J/cm2 was found to be the optimal laser system for nail ablation.
authors.affiliation: Beckman Laser Institute and Medical Clinic, University of California Irvine 92715, USA.
authors.forename: J
authors.initials: J
authors.lastname: Neev
authors.forename: J S
authors.initials: JS
authors.lastname: Nelson
authors.forename: M
authors.initials: M
authors.lastname: Critelli
authors.forename: J L
authors.initials: JL
authors.lastname: McCullough
authors.forename: E
authors.initials: E
authors.lastname: Cheung
authors.forename: W A
authors.initials: WA
authors.lastname: Carrasco
authors.forename: A M
authors.initials: AM
authors.lastname: Rubenchik
authors.forename: L B
authors.initials: LB
authors.lastname: Da Silva
authors.forename: M D
authors.initials: MD
authors.lastname: Perry
authors.forename: B C
authors.initials: BC
authors.lastname: Stuart
mesh_terms: D006801:Humans; D066298:In Vitro Techniques; D053685:Laser Therapy; D009262:Nails / Q000601:surgery* / Q000648:ultrastructure