title: Root instrumentation with an erbium:yttrium-aluminum-garnet laser: effect on the morphology of fibroblasts.
abstract: OBJECTIVE
  The purpose of this study was to evaluate the effect of erbium:yttrium-aluminum-garnet laser instrumentation of root surfaces on the morphology of fibroblasts from continuous lineage.
  
  
  METHODS
  Dentinal slices with 4 mm2 of surface area were obtained from teeth extracted for severe periodontal involvement. Specimens were assigned to one of three treatment groups: group 1, application of the laser with an energy level of 250 mJ at 103 pulses per second; group 2, application of the laser with an energy level of 80 mJ at 166 pulses per second; and group 3, similar to group 2, but with concomitant water irrigation of the device. The specimens were incubated in multiwell plates containing cell culture media. After 24 hours, the specimens were submitted to routine preparation for scanning electron microscopy. Three independent and blind examiners used photomicrographs to evaluate the morphology of the fibroblasts: 0 = without cells; 1 = flat cells; 2 = round cells; and 3 = combination of round and flat cells.
  
  
  RESULTS
  Statistical analysis indicated that there were significant differences among treatment groups and that group 3 was significantly different from groups 1 and 2.
  
  
  CONCLUSIONS
  There was no difference between groups 1 and 2 in the morphology of fibroblasts. Laser instrumentation with concomitant irrigation impaired the adhesion of fibroblasts to dentinal surfaces.
authors.affiliation: Department of Diagnosis and Surgery, School of Dentistry at Araraquara, State University of São Paulo, Araraquara, São Paulo, Brazil. perio@foar.unesp.br
authors.forename: Carlos Júnior
authors.initials: CJ
authors.lastname: Rossa
authors.forename: Karina G
authors.initials: KG
authors.lastname: Silvério
authors.forename: Iriana C J
authors.initials: IC
authors.lastname: Zanin
authors.forename: Aldo Júnior
authors.initials: AJ
authors.lastname: Brugnera
authors.forename: José Eduardo C
authors.initials: JE
authors.lastname: Sampaio
mesh_terms: D000538:Aluminum Silicates; D002448:Cell Adhesion; D018929:Cell Culture Techniques; D019070:Cell Lineage; D048429:Cell Size; D004871:Erbium; D005347:Fibroblasts / Q000473:pathology*; D006801:Humans; D053685:Laser Therapy / Q000379:methods; D008855:Microscopy, Electron, Scanning; D015588:Observer Variation; D010513:Periodontal Ligament / Q000473:pathology*; D016037:Single-Blind Method; D013223:Statistics as Topic; D018709:Statistics, Nonparametric; D007507:Therapeutic Irrigation; D014092:Tooth Root / Q000473:pathology / Q000601:surgery*; D014867:Water; D015019:Yttrium
chemical_list: D000538:Aluminum Silicates; D014867:Water; D015019:Yttrium; D004871:Erbium