title: Assessment of Er:YAG laser for cavity preparation in primary and permanent teeth: a scanning electron microscopy and thermographic study.
abstract: OBJECTIVE
  Most studies of cavity preparation using Er:YAG lasers have employed permanent teeth. This study's purpose was to compare the cutting efficiency of an Er:YAG laser versus diamond burs in primary and permanent teeth in order to measure thermal effects on the pulp and evaluate lased surfaces using scanning electron microscopy (SEM).
  
  
  METHODS
  A total of 80 primary and permanent teeth were used. Crater depths and mass loss were measured after delivering laser pulses at varying energies onto sound or carious enamel or dentin using the Key-3 laser. Control samples were cut using diamond burs in an air turbine handpiece. Thermal changes were measured using miniature thermocouples placed into the pulp chamber. Lased surfaces were evaluated using SEM.
  
  
  RESULTS
  Laser ablation crater-like defects were deeper in dentin than enamel at the same pulse energy. Greater ablation rates for dentin and enamel and significantly more efficient removal of carious tooth structure by laser was present in primary teeth. Temperature rises in the pulp did not exceed the 5.5 degrees Celsius threshold in any teeth during laser ablation.
  
  
  CONCLUSIONS
  The Er:YAG laser is an efficient device for cavity preparations in primary teeth, with no unacceptable increases in temperature detected in this model.
authors: Department of Preventive Dentistry, Faculty of Dentistry, Jordan University of Science and Technology, Ar Ramtha, Irbid, Jordan. olabt@just.edu.jo.
authors: Ola B
authors: OB
authors: Al-Batayneh
authors: Centre for Paediatric Dentistry, The University of Queensland School of Dentistry, Brisbane, Queensland, Australia.
authors: W Kim
authors: WK
authors: Seow
authors: Centre for Paediatric Dentistry, The University of Queensland School of Dentistry, Brisbane, Queensland, Australia.
authors: Laurence J
authors: LJ
authors: Walsh
mesh_terms: D001831:Body Temperature / Q000502:physiology; D003731:Dental Caries / Q000473:pathology / Q000601:surgery; D003737:Dental Cavity Preparation / Q000295:instrumentation*; D003743:Dental Enamel / Q000502:physiology / Q000601:surgery / Q000648:ultrastructure; D003754:Dental High-Speed Equipment; D003782:Dental Pulp / Q000502:physiology; D003786:Dental Pulp Cavity / Q000502:physiology; D003804:Dentin / Q000502:physiology / Q000601:surgery / Q000648:ultrastructure; D018130:Diamond / Q000737:chemistry; D006801:Humans; D053685:Laser Therapy / Q000295:instrumentation*; D053844:Lasers, Solid-State / Q000627:therapeutic use*; D008855:Microscopy, Electron, Scanning; D008904:Miniaturization; D013817:Thermography / Q000379:methods; D013821:Thermometers; D014094:Tooth, Deciduous / Q000502:physiology / Q000601:surgery* / Q000648:ultrastructure
chemical_list: D018130:Diamond