title: Phenomenon of laser power loss during curettage of infected periodontal pockets.
abstract: OBJECTIVE
  The purpose of this study was to evaluate the reduction in laser power output (PO) at the optical fiber tip during laser curettage of infected periodontal pockets.
  
  
  BACKGROUND
  The combination of mechanical debridement with laser therapy has been used successfully in the treatment of periodontitis.
  
  
  METHODS
  The study group consisted of 28 teeth selected in 12 patients with chronic periodontitis. The teeth were treated with scaling and root planing (SRP), and infected pocket epithelium was removed with an 810-nm diode laser operating at a laser power of 1.7 W in continuous-wave mode (CW). Laser power was set to 1.0 W at the control panel before each measurement to facilitate mathematical analysis, and PO at the optical fiber tip was measured using a power meter. Four laser applications were performed per tooth (duration, 10-15 sec per application; total duration, 40-60 sec per tooth). The fiber tip was cleaved every four applications. Also, 28 irradiations (four PO measurements per irradiation) were performed in non-contact mode and used as controls.
  
  
  RESULTS
  There were significant PO losses between applications in the study group. PO losses of 20.89%, 30.39%, and 40.26% were found between the first and second, first and third, and first and fourth applications, respectively. A low transmission loss of the optical fiber was observed in the control measurements (mean PO loss of 1.58% between the first and fourth irradiations).
  
  
  CONCLUSIONS
  Our results indicated that optical fiber tips need to be cleaved frequently during laser curettage to minimize PO loss.
authors: University of São Paulo School of Dentistry, Rua Joaquim Floriano 72, São Paulo, Brazil. silmea@clinicazegaib.com.br
authors: Silméa
authors: S
authors: Zegaib
authors: José L S
authors: JL
authors: Lage-Marques
authors: Martha M F
authors: MM
authors: Vieira
authors: Antonio R Maia
authors: AR
authors: Junior
authors: Magda
authors: M
authors: Feres
authors: Jamil A
authors: JA
authors: Shibli
authors: Luciene C
authors: LC
authors: Figueiredo
mesh_terms: D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D003475:Curettage; D003646:Debridement; D012534:Dental Scaling / Q000295:instrumentation / Q000379:methods*; D011211:Electric Power Supplies; D005260:Female; D006801:Humans; D054023:Lasers, Semiconductor; D028022:Low-Level Light Therapy / Q000295:instrumentation / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010514:Periodontal Pocket / Q000532:radiotherapy*; D016745:Root Planing / Q000295:instrumentation / Q000379:methods; D018709:Statistics, Nonparametric; D016896:Treatment Outcome