title: Micro-Computed Tomography Study of Filling Material Removal from Oval-shaped Canals by Using Rotary, Reciprocating, and Adaptive Motion Systems.
abstract: BACKGROUND
  This study evaluated filling material removal from distal oval-shaped canals of mandibular molars with rotary, reciprocating, and adaptive motion systems by using micro-computed tomography.
  
  
  METHODS
  After cone-beam computed tomography scanning, 21 teeth were selected, prepared up to a size 40 file, root filled, and divided into 3 groups (n = 7) according to the filling material removal technique: group PTUR, ProTaper Universal Retreatment combined with ProTaper Universal F2, F3, F4, and F5 files; group RP, Reciproc R50 file; and group TFA: TF Adaptive 50.04 files. The specimens were scanned preoperatively and postoperatively to assess filling material removal by using micro-computed tomography imaging, and the percent volume of residual filling material was calculated.
  
  
  RESULTS
  The statistical analysis showed the lowest percent volume of residual filling material at the coronal third in all groups (P < .05). There was no significant difference among the systems in the coronal third (P > .05). In the middle third, group TFA (31.2 ± 10.1) showed lower volume of residual filling material than group RP (52.4 ± 14.1) (P < .05). In the apical third, groups TFA (44.8 ± 20.6) and PTUR (48.6 ± 16.8) presented a lower percent volume of filling material than group RP (70.6 ± 7.2) (P < .05), as confirmed by the qualitative analysis.
  
  
  CONCLUSIONS
  The use of the adaptive motion increased the amount of root filling removed in the middle and apical thirds compared with the reciprocating motion. However, no technique was able to completely remove the filling material from the canals.
authors.affiliation: Department of Restorative Dentistry, School of Dentistry of Ribeirão Preto, University of São Paulo, São Paulo, Brazil.
authors.forename: Bruno Monguilhott
authors.initials: BM
authors.lastname: Crozeta
authors.affiliation: University of Ribeirão Preto, Ribeirão Preto, São Paulo, Brazil.
authors.forename: Yara Teresinha Correa
authors.initials: YT
authors.lastname: Silva-Sousa
authors.affiliation: Department of Restorative Dentistry, School of Dentistry of Ribeirão Preto, University of São Paulo, São Paulo, Brazil.
authors.forename: Graziela Bianchi
authors.initials: GB
authors.lastname: Leoni
authors.affiliation: Department of Restorative Dentistry, School of Dentistry of Ribeirão Preto, University of São Paulo, São Paulo, Brazil.
authors.forename: Jardel Francisco
authors.initials: JF
authors.lastname: Mazzi-Chaves
authors.affiliation: University of Ribeirão Preto, Ribeirão Preto, São Paulo, Brazil.
authors.forename: Thais
authors.initials: T
authors.lastname: Fantinato
authors.affiliation: Positivo University, Curitiba, Paraná, Brazil.
authors.forename: Flares
authors.initials: F
authors.lastname: Baratto-Filho
authors.affiliation: Department of Restorative Dentistry, School of Dentistry of Ribeirão Preto, University of São Paulo, São Paulo, Brazil. Electronic address: sousanet@unaerp.br.
authors.forename: Manoel Damião
authors.initials: MD
authors.lastname: Sousa-Neto
mesh_terms: D000704:Analysis of Variance; D019412:Anatomy, Cross-Sectional; D054893:Cone-Beam Computed Tomography; D003722:Dental Alloys / Q000737:chemistry; D003762:Dental Instruments; D003786:Dental Pulp Cavity / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D004853:Epoxy Resins; D004867:Equipment Design; D006171:Gutta-Percha; D006801:Humans; D008334:Mandible; D008963:Molar; D009038:Motion; D009532:Nickel / Q000737:chemistry; D019233:Retreatment; D012387:Root Canal Filling Materials / Q000737:chemistry*; D012388:Root Canal Irrigants; D012389:Root Canal Obturation / Q000295:instrumentation / Q000379:methods*; D018915:Root Canal Preparation / Q000295:instrumentation / Q000379:methods*; D012399:Rotation; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry; D019227:Tooth Apex / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D055114:X-Ray Microtomography / Q000379:methods*
chemical_list: D003722:Dental Alloys; D004853:Epoxy Resins; D012387:Root Canal Filling Materials; D012388:Root Canal Irrigants; C534916:epoxy resin-based root canal sealer; C040654:titanium nickelide; D009532:Nickel; D006171:Gutta-Percha; D014025:Titanium
keywords: Computed microtomography; Retreatment; TFA adaptive; reciprocating motion