ABSTRACT
Background:
An important aspect of the preparation of the access cavity and biomechanical preparation of the root canal is to safeguard as much of the tooth’s framework as possible without affecting access and visibility.
Objectives:
To compare the impact of the conservative design of access preparation and traditional design of access preparation in association with TruNatomy endodontic instrumentation and WaveOne Gold endodontic instrumentation on resistance to fracture by the design of a cavity for endodontic access using finite element analysis
Materials and Methods:
Micro-CT radiographic images of 16 human first permanent molars of the mandible were included in the study to create representative finite element analysis computational models.
Results:
A significant reduction in load for failure after endodontic preparation was observed in TDAP subcategories as compared to specimens with CDAP. However, the reduction in load for failure was comparable in both endodontic instrument systems within the CDAP and TDAP
Conclusion:
A significant reduction in load for failure after endodontic preparation was observed in the traditional design of access preparation subcategories as compared to specimens with the conventional design of access preparation.
KEYWORDS: Access cavity, conventional design, finite element analysis, resistance to fracture, traditional design, TruNatomy, WaveOne gold
INTRODUCTION
To gain access to the coronal one-third and middle one-third of the canal, traditional design access preparations (TDAP) are created by the removal of the roof of the whole pulp chamber.[1,2] Without essentially obtaining straight-line accessibility, the conservative design of access preparation (CDAP) tries to preserve dentin and partial removal of the roof pulp to find canal orifices.[3,4]
Utilizing WaveOne Gold (WOG) and TruNatomy (TN) in conjunction with CDAP requires additional time for preparation than using TDAP designs, according to a recent investigation by Vorster et al.[5,6]
This study was carried out to compare the impact of conservative design of access preparation and traditional design of access preparation in association with TruNatomy endodontic instrumentation and WaveOne Gold endodontic instrumentation on resistance to fracture by the design of cavity for endodontic access using finite element analysis.
MATERIALS AND METHODS
Study groups and sample size in each group
The study specimens were divided into eight categories with each category having two specimens.
Category A: TDAP/WOG.
A1 = control (n = 2).
A2 = access preparation and instrumentation (n = 2).
Category B: CDAP/WOG.
B1 = control (n = 2).
B2 = access preparation and instrumented (n = 2).
Category C: TDAP/TN.
C1: control (n = 2).
C2: instrumented (n = 2).
Category D: CDAP/TN.
D1: control.
D2: instrumented (n = 2).
Geometry acquisitions and finite element analysis (FEA)
Micro-CT radiographic images of 16 human first permanent molars of the mandible were included in the study to create representative finite element analysis computational models.
Statistical analysis
One-way ANOVA statistical test and Chi-square test were used for the statistical examination.
RESULTS
A significant reduction in load for failure (decrease in fracture resistance) after endodontic preparation was observed in TDAP subcategories as compared to specimens with CDAP. However, the reduction in load for failure was similar in both endodontic instrument systems (TN and WOG) within the CDAP and TDAP [Table 1].
Table 1.
Findings of FEA
| Vertical load at failure (kg) | Horizontal load at failure (kg) | Reduction in failure load due to preparation | P | |
|---|---|---|---|---|
| TDAP/WOG | ||||
| Control | 23.38 | 18.92 | 27.43% | 0.012 |
| Instrumented | 17.52 | 14.24 | ||
| CDAP/WOG | ||||
| Control | 18.69 | 15.17 | 2.33% | 0.367 |
| Instrumented | 18.20 | 14.86 | ||
| TDAP/TN | ||||
| Control | 31.58 | 25.49 | 30.23% | 0.021 |
| Instrumented | 22.71 | 18.39 | ||
| CDAP/TN | ||||
| Control | 17.52 | 14.24 | 10.63% | 0.591 |
| Instrumented | 15.95 | 12.98 |
The von Mises stress allocation was highly accumulated at the cervical area and did not transit toward the root. It was noticed that cracks, that is, nonlinearities were largely accumulated at the region of enamel.
DISCUSSION
According to a study by Elkholy et al.,[7] accessibility to the hard tissue of teeth and root canals and its elimination and root canal preparation were more important for resistance to fractures than canal tapering.
There was no discernible disparity in loss of dentin between the TDAP and CDAP categories, according to an investigation by Vorster et al.[6] that measured the thickness of residual dentin and loss of volume of the dentin at the pericervical region after using the WaveOne Gold endodontic file system and TruNatomy endodontic file system.
In a study by Zhang et al.,[8] the more massive palatal root in the first molars of the maxilla was likewise the site of accumulation of stress, which is comparable to what has been shown here. Furthermore, stress patterns and crack development inside enamel matched Zhang et al’s.[8] descriptions.
CONCLUSION
A significant reduction in fracture resistance after endodontic preparation was observed in the traditional design of access preparation subcategories as compared to specimens with the conventional design of access preparation. In addition, when comparing WaveOne Gold with TruNatomy, the researchers came to the conclusion that the kind of root canal instrumentation equipment did not significantly affect improving resistance to fractures.
Financial support and sponsorship
Nil.
Conflicts of interest
There are no conflicts of interest.
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