Micro-CT assessment of dentinal micro-cracks after root canal filling procedures.
OBJECTIVE
To evaluate the frequency of dentinal micro-cracks after root canal filling procedures with GuttaCore (GC), cold lateral compaction (CLC) and warm vertical compaction (WVC) techniques in mandibular molars using micro-computed tomographic analysis.


METHODS
Thirty mesial roots of mandibular molars, with a type II Vertucci's canal configuration, were prepared to working length with a Reciproc R40 instrument and randomly assigned to one of the three experimental groups (n = 10), according to the technique used for root filling: GC, CLC or WVC. The GC group was filled with a size 40 GC obturator, whilst CLC and WVC groups used conventional gutta-percha cones. AH Plus sealer was used in all groups. The specimens were scanned at an isotropic resolution of 14.25 μm before and after root canal preparation and after root filling. Then, all pre- and postoperative cross-sectional images of the roots (n = 41 660) were screened to identify the presence of dentinal defects.


RESULTS
Overall, 30.75% (n = 12 810) of the pre- + post-filling images displayed dentinal defects. In the GC, CLC and WVC groups, dentinal micro-cracks were observed in 18.68% (n = 2510), 15.99% (n = 2389) and 11.34% (n = 1506) of the cross-sectional images, respectively. All micro-cracks identified in the post-filling scans were also observed in the corresponding post-preparation images.


CONCLUSIONS
Root fillings in all techniques did not induce the development of new dentinal micro-cracks.
Department of Endodontics, School of Dentistry, Grande Rio University (UNIGRANRIO), Rio de Janeiro, RJ, Brazil.
G
G
De-Deus
Department of Endodontics, Fluminense Federal University (UFF), Niterói, RJ, Brazil.
F G
http://orcid.org/0000-0001-9972-6861
FG
Belladonna
Department of Endodontics, School of Dentistry, Grande Rio University (UNIGRANRIO), Rio de Janeiro, RJ, Brazil.
E J N L
EJNL
Silva
Department of Dentistry II, Federal University of Maranhão (UFMA), São Luís, MA, Brazil.
E M
EM
Souza
Department of Endodontics, School of Dentistry, Grande Rio University (UNIGRANRIO), Rio de Janeiro, RJ, Brazil.
J C A
JCA
Carvalhal
Department of Endodontics, Fluminense Federal University (UFF), Niterói, RJ, Brazil.
R
http://orcid.org/0000-0003-2192-0124
R
Perez
Nuclear Engineering Program, Federal University of Rio de Janeiro (UFRJ), Rio de Janeiro, RJ, Brazil.
R T
RT
Lopes
Department of Restorative Dentistry, Dental School of Ribeirão Preto, University of São Paulo (USP), Ribeirão Preto, SP, Brazil.
M A
MA
Versiani
D003804:Dentin / Q000000981:diagnostic imaging / Q000293:injuries*; D006171:Gutta-Percha; D006801:Humans; D008334:Mandible; D008963:Molar; D011183:Postoperative Complications / Q000000981:diagnostic imaging*; D012387:Root Canal Filling Materials; D012389:Root Canal Obturation / Q000009:adverse effects*; D014092:Tooth Root / Q000000981:diagnostic imaging / Q000293:injuries*; D055114:X-Ray Microtomography
D012387:Root Canal Filling Materials; D006171:Gutta-Percha
cold lateral compaction; dentinal defects; micro-CT; micro-cracks; root canal filling