title: In vitro study of the variable square pulse Er:YAG laser cutting efficacy for apicectomy.
abstract: OBJECTIVE
  Variable square pulse (VSP) Er:YAG laser should be quicker than older Er:YAG lasers. The objectives were: (1) comparison of VSP laser and mechanical handpiece efficacy for apicectomy and (2) determination of optimal pulse width/energy/frequency combination.
  
  
  METHODS
  Sixty extracted, single-rooted mature human teeth with round apical parts were instrumented, root filled, cleaned, and divided into four groups. Apical 2 mm of each root were apicectomized with mechanical handpiece and Er:YAG laser with three different settings (LaserA = 200 mJ/300 microseconds/ 8 Hz; LaserB = 200 mJ/100 microseconds/8 Hz; LaserC = 380 mJ/100 microseconds/20 Hz). Timing results were statistically compared.
  
  
  RESULTS
  LaserC was the most efficient setting. Differences between groups were significant except between LaserC-Mechanical and LaserA-LaserC (P < 0.05).
  
  
  CONCLUSIONS
  VSP Er:YAG laser used for apicectomy is slower by a factor of 7-31 than mechanical handpiece, but treatment outcome is acceptable. Optimal settings for apicectomy with VSP laser are 380 mJ/100 microseconds/20 Hz.
authors.affiliation: Department of Oral Surgery, School of Dental Medicine, Gundulićeva 5, 10 000 Zagreb, Croatia. josko@sfzg.hr
authors.forename: Josko
authors.initials: J
authors.lastname: Grgurević
authors.forename: Lovro
authors.initials: L
authors.lastname: Grgurević
authors.forename: Ivana
authors.initials: I
authors.lastname: Miletić
authors.forename: Zoran
authors.initials: Z
authors.lastname: Karlović
authors.forename: Silvana Jukić
authors.initials: SJ
authors.lastname: Krmek
authors.forename: Ivica
authors.initials: I
authors.lastname: Anić
mesh_terms: D000328:Adult; D000535:Aluminum; D001047:Apicoectomy / Q000295:instrumentation*; D003762:Dental Instruments; D004871:Erbium; D006801:Humans; D066298:In Vitro Techniques; D053685:Laser Therapy / Q000295:instrumentation*; D007834:Lasers; D011829:Radiation Dosage; D013997:Time Factors; D015019:Yttrium
chemical_list: C503779:yttrium-aluminum-garnet; D015019:Yttrium; D004871:Erbium; D000535:Aluminum