title: Cone beam computed tomographic evaluation of two access cavity designs and instrumentation on the thickness of peri-cervical dentin in mandibular anterior teeth.
abstract: OBJECTIVE
  The aim of the study was to determine the effect of two access cavity designs on the peri-cervical dentin thickness before and after instrumentation using cone beam computed tomography (CBCT).
  
  
  METHODS
  Sixty mandibular anterior teeth were divided into two groups of thirty teeth each: Group I: conventional access cavity preparation, where access was prepared just above the cingulum and Group II: incisal access cavity preparation, where access was prepared in proximity to the incisal edge. CBCT scans were taken preoperatively, following access cavity preparation and post instrumentation. 200 μm thick slices were obtained 4mm apical and coronal to the cemento-enamel junction. The peri-cervical dentin thickness was calculated on the facial, lingual, mesial, and distal for all the three obtained scans.
  
  
  RESULTS
  The analysis showed that access cavity preparation and instrumentation resulted in a significant loss of tooth structure in Group I on all surfaces, but in Group II, there was a significant loss of tooth structure only in the mesial, lingual, and distal surfaces (P < 0.05).
  
  
  CONCLUSIONS
  Incisal access cavity preparation resulted in lesser loss of dentin in the peri-cervical region.
authors.affiliation: Department of Conservative Dentistry and Endodontics, Faculty of Dental Sciences, M S Ramaiah University of Applied Sciences, Bengaluru, Karnataka, India.
authors.forename: Vinny Sara
authors.initials: VS
authors.lastname: Varghese
authors.affiliation: Department of Conservative Dentistry and Endodontics, Faculty of Dental Sciences, M S Ramaiah University of Applied Sciences, Bengaluru, Karnataka, India.
authors.forename: John V
authors.initials: JV
authors.lastname: George
authors.affiliation: Department of Conservative Dentistry and Endodontics, Faculty of Dental Sciences, M S Ramaiah University of Applied Sciences, Bengaluru, Karnataka, India.
authors.forename: Sylvia
authors.initials: S
authors.lastname: Mathew
authors.affiliation: Department of Conservative Dentistry and Endodontics, Faculty of Dental Sciences, M S Ramaiah University of Applied Sciences, Bengaluru, Karnataka, India.
authors.forename: Shruthi
authors.initials: S
authors.lastname: Nagaraja
authors.affiliation: Department of Conservative Dentistry and Endodontics, Faculty of Dental Sciences, M S Ramaiah University of Applied Sciences, Bengaluru, Karnataka, India.
authors.forename: H N
authors.initials: HN
authors.lastname: Indiresha
authors.affiliation: Department of Conservative Dentistry and Endodontics, Faculty of Dental Sciences, M S Ramaiah University of Applied Sciences, Bengaluru, Karnataka, India.
authors.forename: K S
authors.initials: KS
authors.lastname: Madhu
keywords: Cone beam computed tomography; Protaper; incisal access cavity preparation; peri-cervical dentin