Abstract
Introduction
The purpose of this study was to evaluate the impact of conservative endodontic cavities
(CECs) on root canal preparation, restoration, and biomechanical behavior of teeth
prepared using different shaping systems and restorative materials.
Methods
Ninety upper premolars with a bifurcated root were matched based on morphology and
randomly assigned to a control group (n = 10) or 1 of the following experimental groups (n = 40): traditional endodontic cavity and CEC. Teeth were subdivided according to
instrumentation (n = 10) as follows: ProTaper Universal (Dentsply Maillefer, Ballaigues, Switzerland),
Reciproc (VDW GmbH, Munich, Germany), Reciproc Blue (VDW GmbH), and Hyflex EDM (Coltene/Whaledent,
Altstätten, Switzerland). After canal obturation, teeth were restored using temporary
material, conventional composite, regular bulk fill composite, or bulk fill flow combined
with conventional composite. Before and after preparation and after obturation, the
teeth were scanned using micro–computed tomographic imaging. Canal transportation
(CT), the percentage of untouched canal surfaces (UCSs), voids in restoration (VRs),
and residual filling material in the pulp chamber were evaluated. Finite element analysis,
fracture resistance, and the failure pattern were recorded. The data were analyzed
using analysis of variance and the Tukey and chi-square tests.
Results
CECs had greater CT, percentage of filling material, and VRs compared with traditional
endodontic cavities (P < .0001). The highest CT and UCSs were observed in CEC with ProTaper Universal. Bulk
fill flow combined with conventional composite showed a lower percentage of VRs compared
with other restorative materials (P < .05). Finite element analysis, fracture resistance, and failure pattern revealed
similar behaviors in all groups (P > .05) .
Conclusions
CECs had a negative impact on root canal centralization, UCSs, cleaning of the pulp
chamber, and percentage of VRs. Controlled memory instruments were the most adequate
for the root canal preparation of CECs. The endodontic cavity did not influence the
biomechanical behavior of restored teeth.
Key Words
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Article info
Publication history
Published online: March 24, 2021
Identification
Copyright
© 2021 American Association of Endodontists.
