title: Behavior of human periodontal ligament cells on CO2 laser irradiated dentinal root surfaces: an in vitro study.
abstract: OBJECTIVE
  The aim of this study was to investigate the in vitro attachment behavior of human periodontal ligament fibroblasts on periodontally involved root surface after conditioning with CO2 laser and to compare its efficacy with chemical conditioning agents, namely tetracycline hydrochloride, citric acid, hydrogen peroxide (H2O2) and EDTA, using scanning electron microscopy.
  
  
  METHODS
  A total of 84 scaled and root-planed specimens from periodontally involved single-rooted human teeth showing hopeless prognosis were selected and assigned to two groups. One group was lased with a CO2 laser (from 5 cm at 3 W for 0.8, 1.0 and 1.2 s), and the other group was treated with either tetracycline hydrochloride (2.5%), citric acid (saturated solution, pH 1), H2O2 (6%) or EDTA (5%; pH 7.4) for 3 min. The specimens were then seeded with human periodontal ligament fibroblasts, incubated for either 12 h or 24 h, and then the cell attachment behavior was observed.
  
  
  RESULTS
  CO2 laser irradiation for 1.0 s was found to be the most efficient, showing consistently good cell attachment with the highest mean value (15.00 +/- 3.41 cells/10,000 microm2 after incubation for 12 h and 29.17 +/- 2.04 cells/10,000 microm2 after 24 h), followed by irradiation for 0.8 s (13.11 +/- 3.04 cells/10,000 microm2 after incubation for 12 h and 22.91 +/- 7.10 cells/10,000 microm2 after 24 h). Charring was observed following irradiation for 1.2 s. Amongst chemical conditioning agents, citric acid was found to be the most efficient, with a mean cell attachment of 17.82 +/- 2.16 cells/10,000 microm2 after incubation for 12 h and 23.62 +/- 1.94 cells/10,000 microm2 after 24 h. EDTA and H2O2 did not do well in the study.
  
  
  CONCLUSIONS
  The results suggest that CO2 laser irradiation for 1.0 s may promote comparatively better attachment of periodontal ligament fibroblast on dentinal root surfaces than the conventional chemical conditioning agents used in the study.
authors.affiliation: Department of Periodontics, Faculty of Dental Sciences, King George's Medical University, Lucknow, India.
authors.forename: V
authors.initials: V
authors.lastname: Pant
authors.forename: J
authors.initials: J
authors.lastname: Dixit
authors.forename: A K
authors.initials: AK
authors.lastname: Agrawal
authors.forename: P K
authors.initials: PK
authors.lastname: Seth
authors.forename: A B
authors.initials: AB
authors.lastname: Pant
mesh_terms: D000704:Analysis of Variance; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002245:Carbon Dioxide; D002448:Cell Adhesion / Q000187:drug effects / Q000528:radiation effects*; D002478:Cells, Cultured; D002614:Chelating Agents / Q000494:pharmacology; D019343:Citric Acid / Q000494:pharmacology; D003804:Dentin / Q000187:drug effects / Q000528:radiation effects*; D003806:Dentin Permeability / Q000187:drug effects / Q000528:radiation effects*; D004492:Edetic Acid / Q000494:pharmacology; D005347:Fibroblasts / Q000502:physiology; D006801:Humans; D007834:Lasers; D008855:Microscopy, Electron, Scanning; D010513:Periodontal Ligament / Q000166:cytology / Q000502:physiology*; D016369:Smear Layer; D013752:Tetracycline / Q000494:pharmacology; D014092:Tooth Root / Q000187:drug effects / Q000528:radiation effects
chemical_list: D000900:Anti-Bacterial Agents; D002614:Chelating Agents; D002245:Carbon Dioxide; D019343:Citric Acid; D004492:Edetic Acid; D013752:Tetracycline