Assessing accumulated hard-tissue debris using micro-computed tomography and free software for image processing and analysis.
BACKGROUND
The accumulation of debris occurs after root canal preparation procedures specifically in fins, isthmus, irregularities, and ramifications. The aim of this study was to present a step-by-step description of a new method used to longitudinally identify, measure, and 3-dimensionally map the accumulation of hard-tissue debris inside the root canal after biomechanical preparation using free software for image processing and analysis.


METHODS
Three mandibular molars presenting the mesial root with a large isthmus width and a type II Vertucci's canal configuration were selected and scanned. The specimens were assigned to 1 of 3 experimental approaches: (1) 5.25% sodium hypochlorite + 17% EDTA, (2) bidistilled water, and (3) no irrigation. After root canal preparation, high-resolution scans of the teeth were accomplished, and free software packages were used to register and quantify the amount of accumulated hard-tissue debris in either canal space or isthmus areas.


RESULTS
Canal preparation without irrigation resulted in 34.6% of its volume filled with hard-tissue debris, whereas the use of bidistilled water or NaOCl followed by EDTA showed a reduction in the percentage volume of debris to 16% and 11.3%, respectively. The closer the distance to the isthmus area was the larger the amount of accumulated debris regardless of the irrigating protocol used.


CONCLUSIONS
Through the present method, it was possible to calculate the volume of hard-tissue debris in the isthmuses and in the root canal space. Free-software packages used for image reconstruction, registering, and analysis have shown to be promising for end-user application.
Department of Endodontics, Grande Rio University, Rio de Janeiro State University, Rio de Janeiro, Brazil. Electronic address: endogus@gmail.com.
Gustavo
G
De-Deus
Department of Dental Clinics, Rio de Janeiro State University, Rio de Janeiro, Brazil.
Juliana
J
Marins
Department of Endodontics, Grande Rio University, Rio de Janeiro State University, Rio de Janeiro, Brazil.
Aline de Almeida
Ade A
Neves
Department of Dental Clinics, University of Espirito Santo, Espirito Santo, Brazil.
Claudia
C
Reis
Department of Dental Clinics, Rio de Janeiro State University, Rio de Janeiro, Brazil.
Sandra
S
Fidel
Department of Restorative Dentistry, Dental School of Ribeirao Preto, University of São Paulo, São Paulo, Brazil.
Marco A
MA
Versiani
Nuclear Engineering Program, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.
Haimon
H
Alves
Nuclear Engineering Program, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.
Ricardo Tadeu
RT
Lopes
DEMa, PUC-Rio, Rio de Janeiro, Brazil.
Sidnei
S
Paciornik
D019412:Anatomy, Cross-Sectional; D003722:Dental Alloys; D003786:Dental Pulp Cavity / Q000000981:diagnostic imaging*; D004492:Edetic Acid / Q000627:therapeutic use; D004867:Equipment Design; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008963:Molar / Q000000981:diagnostic imaging; D009532:Nickel / Q000737:chemistry; D012388:Root Canal Irrigants / Q000627:therapeutic use; D018915:Root Canal Preparation / Q000295:instrumentation / Q000379:methods; D016369:Smear Layer / Q000000981:diagnostic imaging*; D012973:Sodium Hypochlorite / Q000627:therapeutic use; D012984:Software; D014025:Titanium / Q000737:chemistry; D014867:Water; D055114:X-Ray Microtomography / Q000379:methods*
D003722:Dental Alloys; D012388:Root Canal Irrigants; D014867:Water; C040654:titanium nickelide; D009532:Nickel; D004492:Edetic Acid; D014025:Titanium; D012973:Sodium Hypochlorite
Biomechanical preparation; debris; free software; irrigation; micro-computed tomography; root canal system