title: Peripheral dentin thickness after root-end cavity preparation.
abstract: OBJECTIVE
  The objective of this study was to determine if it was possible to retain 2 mm of dentin around the periphery of root-end cavity preparations in maxillary central incisor and maxillary canine teeth.
  
  
  METHODS
  Thirty teeth of each type were root filled. Three millimeters of root end was resected and conservative root-end cavities ultrasonically prepared. Root ends were photographed and measured using a computer program. Teeth without 2 mm of peripheral dentin were sectioned for up to 3 further 1-mm increments.
  
  
  RESULTS
  None of the central incisors had 2 mm of dentin remaining at the 3-mm resection level, and none of the canines had 2 mm of dentin remaining even after resecting to 6 mm.
  
  
  CONCLUSIONS
  Recommendations to preserve 2 mm of structure around the root-end cavities of these teeth are unrealistic.
authors.affiliation: Department of Oral Rehabilitation, University of Otago School of Dentistry, Dunedin, New Zealand.
authors.forename: Rajneesh
authors.initials: R
authors.lastname: Roy
authors.forename: Nicholas Paul
authors.initials: NP
authors.lastname: Chandler
authors.forename: Jack
authors.initials: J
authors.lastname: Lin
mesh_terms: D001047:Apicoectomy; D003481:Cuspid; D003786:Dental Pulp Cavity / Q000033:anatomy & histology*; D003804:Dentin / Q000033:anatomy & histology*; D005240:Feasibility Studies; D006801:Humans; D007180:Incisor; D008437:Maxilla; D009811:Odontometry; D012015:Reference Standards; D012184:Retrograde Obturation; D018915:Root Canal Preparation / Q000295:instrumentation*