title: Influence of an erbium, chromium-doped yttrium, scandium, gallium, and garnet (Er,Cr:YSGG) laser on the reestablishment of the biocompatibility of contaminated titanium implant surfaces.
abstract: BACKGROUND
  The aim of the present study was to evaluate the influence of an erbium, chromium-doped yttrium, scandium, gallium, and garnet (Er,Cr:YSGG laser [ERCL]) on 1) the surface structure and biocompatibility of titanium implants and 2) the removal of plaque biofilms and reestablishment of the biocompatibility of contaminated titanium surfaces.
  
  
  METHODS
  Intraoral splints were used to collect an in vivo supragingival biofilm on sand-blasted and acid-etched titanium disks for 24 hours. ERCL was used at an energy output of 0.5, 1.0, 1.5, 2.0, and 2.5 W for the irradiation of 1) non-contaminated (20 and 25 Hz) and 2) plaque-contaminated (25 Hz) titanium disks. Unworn and untreated non-irradiated, sterile titanium disks served as untreated controls (UC). Specimens were incubated with SaOs-2 osteoblasts for 6 days. Treatment time, residual plaque biofilm (RPB) areas (%), mitochondrial cell activity (MA) (counts per second), and cell morphology/surface changes (scanning electron microscopy [SEM]) were assessed.
  
  
  RESULTS
  1) ERCL using either 0.5, 1.0, 1.5, 2.0, or 2.5 W at both 20 and 25 Hz resulted in comparable mean MA values as measured in the UC group. A monolayer of flattened SaOs-2 cells showing complete cytoplasmatic extensions and lamellopodia was observed in both ERCL and UC groups. 2) Mean RPB areas decreased significantly with increasing energy settings (53.8 +/- 2.2 at 0.5 W to 9.8 +/- 6.2 at 2.5 W). However, mean MA values were significantly higher in the UC group.
  
  
  CONCLUSIONS
  Within the limits of the present study, it was concluded that even though ERCL exhibited a high efficiency to remove plaque biofilms in an energy-dependent manner, it failed to reestablish the biocompatibility of contaminated titanium surfaces.
authors.affiliation: Department of Oral Surgery, Heinrich Heine University, Düsseldorf, Germany. info@frank-schwarz.de
authors.forename: Frank
authors.initials: F
authors.lastname: Schwarz
authors.forename: Enaas
authors.initials: E
authors.lastname: Nuesry
authors.forename: Katrin
authors.initials: K
authors.lastname: Bieling
authors.forename: Monika
authors.initials: M
authors.lastname: Herten
authors.forename: Jürgen
authors.initials: J
authors.lastname: Becker
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D018441:Biofilms / Q000528:radiation effects*; D002448:Cell Adhesion; D002470:Cell Survival; D002478:Cells, Cultured; D002857:Chromium; D003666:Decontamination / Q000295:instrumentation / Q000379:methods*; D015921:Dental Implants / Q000382:microbiology*; D003773:Dental Plaque / Q000628:therapy; D004871:Erbium; D005260:Female; D006801:Humans; D007834:Lasers; D008297:Male; D008422:Materials Testing; D010006:Osteoblasts / Q000502:physiology / Q000528:radiation effects; D018709:Statistics, Nonparametric; D013499:Surface Properties; D014025:Titanium / Q000528:radiation effects*
chemical_list: D015921:Dental Implants; D002857:Chromium; D004871:Erbium; D014025:Titanium