Abstract
Introduction
This study investigated the impact of different canal tapers and access cavity designs
on the life span of endodontically treated mandibular first molars using the finite
element method.
Methods
Finite element analysis was performed on simulated models with 3 access cavity designs
(traditional, conservative, and truss). The mesial canals were prepared to either
constant tapers of 25/.04 and 25/.06 or a variable taper corresponding to the cumulative
canal preparation shapes of TruNatomy Prime (Dentsply Sirona, Charlotte, NC) and ProTaper
Gold F2 (Dentsply Sirona). The distal canals in all models had a 40/.04 preparation.
Using occlusal fingerprint analysis, all models were subjected to cyclic occlusal
loading until model failure. The number of cycles until failure, the location of failure,
stress distribution patterns, and the maximum von Mises stresses were assessed.
Results
The traditional access models showed a lower life span than the conservative and truss
models regardless of the canal taper, whereas there was not a notable difference in
the conservative and truss models. The stresses migrated apically along the root surface
and remarkably on the mesial aspect of the mesial root and the furcation area’s outer
surface. After root canal preparation with different tapers, there were no evident
changes in the pattern and magnitude of the stresses distributed along the root surface.
Conclusions
The life span of the tooth is affected more significantly by the access cavity design
than the root canal preparation taper. Because stress patterns migrate apically rather
than concentrate in the pericervical area, crack initiation and propagation might
occur anywhere on the root surface.
Key Words
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Article info
Publication history
Published online: June 14, 2021
Identification
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© 2021 American Association of Endodontists.
