title: A randomized investigator-blind trial of different passes of microdermabrasion therapy and their effects on skin biophysical characteristics.
abstract: BACKGROUND
  Microdermabrasion (MDA) is a safe, simple, and beneficial technique for superficial skin resurfacing. Despite its popular usage, few studies have assessed the efficacy of different MDA protocols applied at the present time. Objectives To assess the effects of MDA generally, as well as to compare the effects of two vs. three passes of MDA in each session for a total number of six therapeutic sessions on skin biophysical characteristics.
  
  
  METHODS
  In this randomized, investigator-blind, split-face study, 10 patients underwent a series of six MDA treatments with an interval of 2 weeks. One side of the face was treated with two passes of MDA and the other side was treated with three passes, randomly. Stratum corneum hydration, sebum secretion, and skin pH measurements were obtained before and after the procedure on all sessions and also 1 and 4 weeks after the last treatment.
  
  
  RESULTS
  After six sessions of MDA, a decrease in sebum content compared to baseline was shown at the end of treatment sessions, but no statistical difference was observed between two vs. three passes groups (-30.0 [interquartile range, IQR = 50.0] vs. -27.5 [IQR = 125.3], respectively, P = 0.58). Comparison of two treatment groups showed significant higher values of sebum content in the first follow-up after treatment with three passes of MDA. (64.0 [IQR = 52.0] for three passes vs. 45.0 [IQR = 46.0] for two passes, P = 0.04) A significant increase was observed in pH values at the end of treatment series, first and second follow-up after treatment with two passes of MDA.
  
  
  CONCLUSIONS
  MDA may have remarkable effects on skin barrier function changes resulting in skin clinical improvements (Cochrane Skin Group identifier: CSG No. 37).
authors.affiliation: Center for Research & Training in Skin Diseases and Leprosy, Medical Sciences, University of Tehran, Tehran, Iran.
authors.forename: Parastoo
authors.initials: P
authors.lastname: Davari
authors.forename: Farzam
authors.initials: F
authors.lastname: Gorouhi
authors.forename: Sirous
authors.initials: S
authors.lastname: Jafarian
authors.forename: Yahya
authors.initials: Y
authors.lastname: Dowlati
authors.forename: Alireza
authors.initials: A
authors.lastname: Firooz
mesh_terms: D000328:Adult; D003869:Dermabrasion / Q000379:methods*; D062109:Dermatologic Surgical Procedures; D025802:Electric Capacitance; D005260:Female; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D008875:Middle Aged; D017060:Patient Satisfaction; D012629:Sebum / Q000378:metabolism; D016037:Single-Blind Method; D012867:Skin / Q000737:chemistry / Q000378:metabolism; D015595:Skin Aging; D012871:Skin Diseases / Q000378:metabolism / Q000601:surgery*; D012879:Skin Physiological Phenomena; D018709:Statistics, Nonparametric; D016896:Treatment Outcome; D014867:Water / Q000032:analysis
chemical_list: D014867:Water