title: Evaluation of root-end preparation with a new ultrasonic tip.
abstract: BACKGROUND
  This study was conducted to evaluate the effect of a new ultrasonic tip (Jetip) for root-end preparation.
  
  
  METHODS
  A total of 80 single-rooted teeth were endodontically treated, and the apical 3 mm of the root apex was resected. Teeth were randomly distributed into 2 experimental groups according to the ultrasonic tips used to prepare the root-end cavity. Epoxy resin replicas of root-end surfaces after root-end resection were obtained. A root-end cavity was then prepared with an ultrasonic tip, either Jetip or AS3D. Replicas of the apices were fabricated after the retropreparations, and they were processed for analysis by scanning electron microscopy (SEM) to evaluate the presence of microcracks and the quality of the root-end preparation. The morphologic characteristics of the ultrasonic tip were also assessed by SEM. The time required for root-end preparation was recorded.
  
  
  RESULTS
  There were no statistically significant differences between the Jetip and AS3D groups in the mean time for the root-end preparation, the incidence of microcracks, or the quality of the root-end preparation (P > .05). SEM analysis showed that Jetip exhibited smoothed microprojections after the root preparations, whereas the loss of diamond particles was observed in AS3D.
  
  
  CONCLUSIONS
  Both Jetip and AS3D provided rapid and regular root-end preparations. The cutting efficiencies of both Jetip and AS3D decreased with the number of times the tips were used. The Jetip showed smooth microprojections after root-end preparation, whereas the AS3D tip exhibited the loss of diamond particles.
authors.affiliation: Guanghua School of Stomatology and Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou, China.
authors.forename: Zhengzheng
authors.initials: Z
authors.lastname: Liu
authors.forename: Deqian
authors.initials: D
authors.lastname: Zhang
authors.forename: Qimeng
authors.initials: Q
authors.lastname: Li
authors.forename: Qiong
authors.initials: Q
authors.lastname: Xu
mesh_terms: D001047:Apicoectomy / Q000295:instrumentation* / Q000379:methods; D018130:Diamond / Q000737:chemistry; D004867:Equipment Design; D006801:Humans; D008855:Microscopy, Electron, Scanning; D008866:Microsurgery / Q000295:instrumentation; D061646:Operative Time; D016628:Replica Techniques; D012389:Root Canal Obturation / Q000379:methods; D018915:Root Canal Preparation / Q000379:methods; D013499:Surface Properties; D019227:Tooth Apex / Q000648:ultrastructure; D059708:Ultrasonic Surgical Procedures / Q000295:instrumentation* / Q000379:methods
chemical_list: D018130:Diamond