title: Comparative study on morphologic changes and cell attachment of periodontitis-affected root surfaces following conditioning with CO2 and Er:YAG laser irradiations.
abstract: OBJECTIVE
  Clinical application of lasers in periodontal therapy has continued to expand in last decades; however there are still some controversies. The present study aimed to compare the conditioning effects of the carbon dioxide (CO2) or erbium-doped: yttrium, aluminum and garnet (Er:YAG) laser on periodontally diseased root surfaces following scaling and root planing (SRP) in terms of the alteration of morphologies as well as the attachment of periodontal ligament cells.
  
  
  METHODS
  Forty-five periodontally affected root specimens were prepared and randomly assigned into three groups: I control (untreated diseased), II. SRP+CO2 laser (pulsed, noncontact mode), and III. SRP+Er:YAG laser (slight contact mode). After treatment, five specimens in each group were used for surface topographic examination. The remaining 10 specimens in each group were incubated with human periodontal ligament cell suspension. All the specimens were finally evaluated by scanning electron microscopy.
  
  
  RESULTS
  The control specimens showed the lowest number of cultured cells, mostly in oval shape, with no tightly attached cells. The CO2 lased specimens showed a significant increase in the number of attached cells compared with controls, but demonstrated some major thermal alterations on the surfaces. The Er:YAG lased specimens showed the significantly highest number of attached cells, mostly in flat form, and did not show distinct thermal damage.
  
  
  CONCLUSIONS
  The present study suggests that compared with the CO2 laser, the Er:YAG laser may constitute a more useful conditioning tool for enhancing periodontal cell attachment to periodontally diseased root surfaces, with fewer undesirable thermal side effects.
authors.affiliation: 1 Department of Oral Medicine, Periodontology & Oral Diagnosis, Faculty of Oral & Dental Medicine, Fayoum University , Bahaariy Region, Al-Fayoum, Egypt .
authors.forename: Mahmoud Helmy
authors.initials: MH
authors.lastname: Belal
authors.forename: Hisashi
authors.initials: H
authors.lastname: Watanabe
mesh_terms: D002245:Carbon Dioxide; D002448:Cell Adhesion / Q000528:radiation effects*; D012534:Dental Scaling; D006801:Humans; D066298:In Vitro Techniques; D053685:Laser Therapy / Q000295:instrumentation / Q000379:methods*; D054020:Lasers, Gas; D053844:Lasers, Solid-State; D008855:Microscopy, Electron, Scanning; D010518:Periodontitis / Q000532:radiotherapy*; D011897:Random Allocation; D013499:Surface Properties; D014016:Tissue Conditioning, Dental / Q000295:instrumentation / Q000379:methods*; D014092:Tooth Root / Q000528:radiation effects* / Q000648:ultrastructure
chemical_list: D002245:Carbon Dioxide