title: Comparative CBCT evaluation of the efficacy of Nd:YAG laser and K3 rotary system in non-surgical root canal retreatment.
abstract: BACKGROUND
  The aim of the present study was to compare the efficacy of Nd:YAG laser and K3 rotary system in the non-surgical root canal retreatment.
  
  
  METHODS
  Sixty-one rooted human teeth were divided into two groups of 30 after root canal therapy. In groups 1 and 2 root canal retreatments were carried out using K3 rotary system and Nd:YAG laser, respectively. CBCT images were used to evaluate canal transportation and root canal debridement at coronal, middle and apical canal cross-sections. In addition, the time necessary for canal debridement and the temperature on the external root surface were calculated. Mann-Whitney U test was used for statistical analysis of data with SPSS 17 after means ± SD were calculated. Shapiro-Wilk test was used to evaluate normal distribution of data. Statistical significance was defined at P<0.05.
  
  
  RESULTS
  The mean time necessary for the debridement of root canals in the laser group was significantly shorter than that in the K3 group (P=0.001). However, there were no significant differences in external root surface temperatures between the two groups (P=0.17). The coronal third of the canals was cleaner in the laser group significantly (p=0.01). Less canal transportation was seen in the laser group compared to the K3 group, significantly (P=0.04).
  
  
  CONCLUSIONS
  Nd:YAG is superior to K3 rotary system in the non-surgical root canal retreatment because it is faster and results in less canal transportation in the middle and apical thirds of the canals.
authors: Department of Endodontics, Dental Faculty Tabriz University (Medical Sciences), Tabriz, Iran - neginghasemi64@gmail.com.
authors: Mohammad
authors: M
authors: Samiei
authors: Negin
authors: N
authors: Ghasemi
authors: Ali
authors: A
authors: Torab
authors: Saeed
authors: S
authors: Rahimi
authors: Mehdi
authors: M
authors: Niknami
authors: Sahand
authors: S
authors: Rikhtegaran
authors: Fatemeh
authors: F
authors: Purnaghi Azar
authors: Seyad
authors: S
authors: Mehdi Vahid Pakdel
mesh_terms: D054893:Cone-Beam Computed Tomography; D003646:Debridement / Q000295:instrumentation / Q000379:methods; D003762:Dental Instruments; D004867:Equipment Design; D006171:Gutta-Percha; D006801:Humans; D066298:In Vitro Techniques; D053844:Lasers, Solid-State; D010865:Pilot Projects; D011897:Random Allocation; D019233:Retreatment; D018915:Root Canal Preparation / Q000295:instrumentation / Q000379:methods*; D013997:Time Factors; D014070:Tooth / Q000000981:diagnostic imaging*
chemical_list: D006171:Gutta-Percha