ABSTRACT
Objective:
To investigate the effects of straight-line minimally invasive access cavity on the mechanical properties of endodontically treated maxillary first
premolars using
finite element analysis.
Methods:
Micro-CT data of twenty maxillary first
premolars were collected for three-dimensional reconstruction. Three access cavities, including the conventional access cavity (ConvAC), the truss access cavity (TrussAC) and the straight-line minimally invasive access cavity (SMIAC), as well as the
root canal treatment procedure, were simulated in all the 20 reconstruction samples of three-dimensional models, respectively. The peak von Mises stress on the cervical area of each model, as well as the stress distribution under vertical and oblique loading circumstances, were subsequently determined by using
finite element analysis.
Results:
In comparison to the stresses of ConvAC [buccal cervical (BC) (188.7±13.4) MPa, palatal cervical (PC) (200.9±25.7) MPa], the stresses of TrussAC [BC (146.0±12.9) MPa, PC (167.6±15.9) MPa] (t=9.01, P<0.001; t=4.59, P<0.001) and SMIAC [BC (142.6±13.7) MPa, PC (168.1±17.4) MPa] (t=9.64, P<0.001; t=3.76, P=0.004) significantly reduced the peak von Mises stress on the cervical area of the maxillary first
premolars after
root canal treatment. Under vertical loading conditions, SMIAC also reduced the central tendency of stresses on the occlusal surface, cervical area and root. In the case of oblique loading conditions,
similar results were observed. Under both loading conditions, there was no significant difference in the peak von Mises stress on the cervical area of the maxillary first
premolar between TrussAC and SMIAC groups.
Conclusions:
The design of SMIAC could preserve the mechanical properties of the maxillary first
premolar following
root canal treatment, which might have certain clinical feasibility.