title: Cone-beam Computed Tomography Evaluation of Root Canal Preparation using Various Rotary Instruments: An in vitro Study.
abstract: To evaluate the remaining dentin thickness of teeth after cleaning and shaping the root canal using three rotary instrumentation technique using cone-beam computed tomography (CBCT).
  
  
  
  This in vitro study is being done with 30 premolar samples with 20' curvature. The study is divided into three groups a CBCT was taken to measure the shortest distance from the root canal outline to the closest adjacent root surface was measured at each level from the cementoenamel junction (CEJ) (1,3, 5 and 7 mm) before and after root canal instrumentation. The purpose of this study was to compare the effects of different instruments used to prepare curved root canals on the remaining cervical dentin thickness and total amount of dentin removed from root canals during instrumentation by using multi-slice CBCT. The remaining dentin thickness is very much necessary for the success rate of root canal treatment. However, this study helps to prove that a conservative preparation with a sound remaining dentin thickness is much more advisable.
  
  
  
  It was observed that there was a significant difference at 1 and 3 mm (p < 0.05) and at 5 and 7 mm there was no significant difference ( p > 0.05). Mtwo has removed less amount dentin when compared to ProTaper Universal and ProTaper Next system at 1 and 3 mm.
  
  
  
  Under the conditions of the study, we concluded that ProTaper Universal and ProTaper Next should be used judiciously, as it causes higher thinning of root dentin of the root when compared with Mtwo.
authors.affiliation: Undergraduate Student, Department of Conservative Dentistry and Endodontics Saveetha Dental College and Hospital, Chennai, Tamil Nadu India, India, e-mail: suhasnathan@yahoo.in.
authors.forename: Suhashini
authors.initials: S
authors.lastname: Ramanathan
authors.affiliation: Department of Conservative Dentistry and Endodontics Saveetha Dental College and Hospital, Chennai, Tamil Nadu India.
authors.forename: Pradeep
authors.initials: P
authors.lastname: Solete
mesh_terms: D054893:Cone-Beam Computed Tomography; D003786:Dental Pulp Cavity; D003804:Dentin; D004867:Equipment Design; D006801:Humans; D018915:Root Canal Preparation
keywords: Cone-beam computed tomography; Dentin thickness; Heroshaper rotary instrumentation; iRace; Nickeltitanium; ProTaper