Efficacy of ProTaper NEXT Compared with Reciproc in Removing Obturation Material from Severely Curved Root Canals: A Micro-Computed Tomography Study.
BACKGROUND
The aim of this study was to compare the remaining root canal obturation, volume of dentin removed, and apical transportation after retreatment of severely curved root canals by using Reciproc (REC) or ProTaper NEXT (PTN) systems.


METHODS
Twenty-eight mesial canals of mandibular molars were instrumented and then obturated with gutta-percha and sealer and allocated into 2 balanced groups (n = 14), the REC group (R25 file) and the PTN group (X3 and X2 files). Micro-computed tomography analysis was performed to assess the percentage of residual obturation material, the amount of dentin removed, and apical transportation. The effective time for the removal of obturation and procedural errors were recorded.


RESULTS
Obturation was effectively removed from the root canal in the REC and PTN groups (P ≤ .001), and the percentages of remaining obturation material were similar between both groups (84.8% PTN vs 86.5% REC) (P > .05). The amount of dentin removed (3.17 ± 2.64 mm(3) PTN versus 3.50 ± 2.82 mm(3) REC), apical transportation (at 1 mm: 0.096 ± 0.189 mm PTN versus 0.093 ± 0.186 mm REC; at 3 mm: 0.059 ± 0.069 mm PTN versus 0.082 ± 0.080 mm REC; at 5 mm: 0.097 ± 0.093 mm PTN versus 0.133 ± 0.138 mm REC), and the working time (269.69 ± 19.25 seconds PTN versus 268.62 ± 16.37 seconds REC) were also similar in both groups (P > .05). One file fractured in the REC group.


CONCLUSIONS
Both systems were equally effective in the removal of obturation from severely curved canals and can be used for retreatment. Neither system could completely remove the obturation material; therefore, additional techniques are needed to improve cleaning of the root canal.
Department of Operative Dentistry and Endodontics, Dental College of Pernambuco, University of Pernambuco, Camaragibe, Pernambuco, Brazil. Electronic address: gnevares@yahoo.com.
Giselle
G
Nevares
Department of Operative Dentistry and Endodontics, Dental College of Pernambuco, University of Pernambuco, Camaragibe, Pernambuco, Brazil.
Diana S
DS
de Albuquerque
School of Dentistry, University of São Paulo, São Paulo, São Paulo, Brazil.
Laila G
LG
Freire
Department of Operative Dentistry and Endodontics, Dental College of Pernambuco, University of Pernambuco, Camaragibe, Pernambuco, Brazil.
Kaline
K
Romeiro
Division of Endodontics, College of Dentistry, University of Manitoba, Winnipeg, Manitoba, Canada.
Howard M
HM
Fogel
Division of Endodontics, Restorative Dentistry, School of Dentistry, University of São Paulo, São Paulo, São Paulo, Brazil.
Marcelo
M
Dos Santos
Division of Endodontics, College of Dentistry, University of Manitoba, Winnipeg, Manitoba, Canada.
Rodrigo S
RS
Cunha
D003722:Dental Alloys; D003762:Dental Instruments; D003786:Dental Pulp Cavity / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D003804:Dentin; D004853:Epoxy Resins; D004867:Equipment Design; D006171:Gutta-Percha; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods; D008334:Mandible; D008422:Materials Testing; D008963:Molar / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D009532:Nickel; D010865:Pilot Projects; D019233:Retreatment; D012387:Root Canal Filling Materials; D012388:Root Canal Irrigants; D012389:Root Canal Obturation / Q000295:instrumentation* / Q000379:methods*; D018915:Root Canal Preparation / Q000295:instrumentation* / Q000379:methods*; D012997:Solvents; D013499:Surface Properties; D014025:Titanium; D019227:Tooth Apex / Q000033:anatomy & histology / Q000000981:diagnostic imaging*; D055114:X-Ray Microtomography / Q000379:methods*
D003722:Dental Alloys; D004853:Epoxy Resins; D012387:Root Canal Filling Materials; D012388:Root Canal Irrigants; D012997:Solvents; C040654:titanium nickelide; D009532:Nickel; D006171:Gutta-Percha; D014025:Titanium
Apical transportation; gutta-percha removal; retreatment; root canal obturation material