title: Comparison of warm vertical compaction protocols to obturate artificially created defects in the apical one-third.
abstract: BACKGROUND
  The purpose of this study was to evaluate the ability of 4 different warm vertical compaction protocols to obturate artificially created defects in the apical one-third of a root canal system by using a split-tooth model.
  
  
  METHODS
  Four warm vertical protocols used (A) continuous down-pack and continuous backfill, (B) continuous down-pack and incremental backfill, (C) incremental down-pack and continuous backfill, and (D) incremental down-pack and incremental backfill. Three artificially created defects were placed 2, 3, and 4 mm from the apex of the split-tooth model. Before obturations, a fine-medium System B plugger was prefitted 4 mm from the working length. The root canal system was obturated according to each of the experimental protocols. Resultant obturations (N = 10/protocol) were separated from the model, and replicated defects were assessed by a blinded evaluator who used an ordinal scale (0-4) that was based on how much each defect was replicated by GP.
  
  
  RESULTS
  By using nonparametric analyses with Bonferroni adjustment (α = 0.01), with the apical 2-mm defect, protocol D demonstrated significantly (P ≤ .01) better defect replication as compared with protocols A, B, and C. For the apical 3-mm defect, protocols B and D were significantly better (P ≤ .01) than protocols A and C. However, there was no difference (P > .01) between protocols with apical 4-mm defect (100% replication).
  
  
  CONCLUSIONS
  The incremental down-pack with incremental backfill appears better able to replicate the most apical defect, which suggests benefits of repeated heat application and packing force to manipulate the GP in the apical plug area.
authors: Department of Endodontics, University of Missouri-Kansas City School of Dentistry, Kansas City, Missouri 64108, USA. perrycan@umkc.edu
authors: Candice
authors: C
authors: Perry
authors: James C
authors: JC
authors: Kulild
authors: Mary P
authors: MP
authors: Walker
mesh_terms: D003786:Dental Pulp Cavity / Q000473:pathology*; D006171:Gutta-Percha / Q000737:chemistry*; D006358:Hot Temperature; D006801:Humans; D008422:Materials Testing; D008853:Microscopy / Q000295:instrumentation; D012387:Root Canal Filling Materials / Q000737:chemistry*; D012389:Root Canal Obturation / Q000295:instrumentation / Q000379:methods*; D018915:Root Canal Preparation / Q000295:instrumentation / Q000379:methods; D013499:Surface Properties; D019227:Tooth Apex / Q000473:pathology*
chemical_list: D012387:Root Canal Filling Materials; D006171:Gutta-Percha
keywords: Apical defect replication; backfill; down-pack; warm vertical compaction