title: Phenothiazine chloride and soft laser light have a biostimulatory effect on human osteoblastic cells.
abstract: OBJECTIVE
  Low-level laser therapy (LLLT) is a well accepted tool to accelerate wound healing and to reduce inflammation after oral implant insertion. Since there are no in vitro data on a combination of LLLT with prior photosensitization, it was the aim of this study to investigate if photosensitization with phenothiazine chloride results in an alteration of the biostimulatory effect of low-level laser irradiation.
  
  
  BACKGROUND
  LLLT and antimicrobial photodynamic therapy are well established for the treatment of peri-implantitis. In vitro studies have shown a biostimulatory effect of LLLT on various cell types, including osteogenic cells.
  
  
  METHODS
  SaOS-2 cells were treated with the photosensitizer phenothiazine chloride before irradiation with matched laser light. At 24-h intervals the viability and differentiation were analyzed in treated and untreated cells.
  
  
  RESULTS
  While the biostimulatory effect of the LLLT could be observed for the lower irradiation dose, the pretreatment with phenothiazine chloride did not significantly affect the growth and differentiation of the SaOS-2 cells.
  
  
  CONCLUSIONS
  It can thus be concluded that combined treatment with phenothiazine chloride and LLLT does not result in a synergistic enhancement of the biostimulatory effect of LLLT, but there was also no evidence for antagonizing effects on growth and differentiation of human osteoblasts.
authors.affiliation: Department of Cranio-Maxillofacial and Oral Surgery, Medical University of Vienna, Vienna, Austria.
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Stein
authors.forename: Jadranka
authors.initials: J
authors.lastname: Koehn
authors.forename: Walter
authors.initials: W
authors.lastname: Sutter
authors.forename: Constanze
authors.initials: C
authors.lastname: Schmidl
authors.forename: Vesna
authors.initials: V
authors.lastname: Lezaic
authors.forename: Gabriele
authors.initials: G
authors.lastname: Wendtlandt
authors.forename: Franz
authors.initials: F
authors.lastname: Watzinger
authors.forename: Dritan
authors.initials: D
authors.lastname: Turhani
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D002470:Cell Survival / Q000528:radiation effects; D024042:Collagen Type I / Q000378:metabolism; D015921:Dental Implants; D006801:Humans; D028022:Low-Level Light Therapy; D010006:Osteoblasts / Q000166:cytology / Q000378:metabolism / Q000528:radiation effects*; D010640:Phenothiazines / Q000494:pharmacology*; D017319:Photosensitizing Agents / Q000494:pharmacology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014407:Tumor Cells, Cultured
chemical_list: D024042:Collagen Type I; D015921:Dental Implants; D010640:Phenothiazines; D017319:Photosensitizing Agents; D000469:Alkaline Phosphatase