Comparative Evaluation of Debris Extrusion, Remaining Dentin Thickness and Fracture Resistance of Endodontically Treated Teeth Using Rotary and Reciprocating Endodontic File Systems: An In Vitro Study

Abstract

Background: Preventing the apical extrusion of debris during instrumentation is of paramount importance to reduce the occurrence of flare-ups in endodontically treated teeth. Furthermore, an essential requirement for the longevity and strength of an endodontically treated tooth and its ability to resist fracture is the preservation of residual dentin thickness during instrumentation. The aim of this study was to compare the amount of debris extrusion, remaining dentin thickness at the coronal third, middle third, apical third, and the fracture resistance of the teeth using rotary (TruNatomy; Dentsply Sirona, Charlotte, NC) and reciprocating (WaveOne Gold; Dentsply Sirona) endodontic file systems.

Methods: An in vitro study included 52 single-rooted, oval canal shaped teeth that underwent exploration and initial cleaning with a no. 15 K-file. The prepared canals were then randomly assigned to two groups: Group I, with instrumentation with the TruNatomy rotary file (n=26) and Group II, with instrumentation with the WaveOne Gold reciprocating file. Parameters like debris extrusion, remaining dentin thickness, and fracture resistance were evaluated in both the groups. Analysis was performed using a paired t-test for the assessment of difference between groups and one-way ANOVA test followed by the post-hoc Tukey test for difference between the coronal, middle and apical third for each study group.

Results: The results revealed no significant difference (t=0.454, p=0.652) between the TruNatomy rotary file and WaveOne Gold reciprocating file in apical extrusion of debris after their use in root canal therapy. For the remaining dentin thickness, a significant difference was present between the TruNatomy rotary file and WaveOne Gold reciprocating rotary file at the coronal (t=5.766, p<0.0001) and middle (t=3.690, p=0.001) levels. The mean fracture resistance was significantly more (t=15.877, p<0.0001) with the TruNatomy rotary file compared to the WaveOne Gold reciprocating rotary file.

Conclusion: The TruNatomy rotary file system outperformed the WaveOne Gold reciprocating file system in terms of maintaining the remaining dentin thickness and providing improved fracture resistance. Nevertheless, debris extruded apically was comparable between the TruNatomy rotary file system and the WaveOne Gold reciprocating file system.

Keywords: debris extrusion; fracture resistance; remaining dentin thickness; root canal preparation; trunatomy; waveone gold.

Figure 1. Pictorial representation of the study procedure

(a) Extracted single-rooted teeth. (b) A digital radiograph was taken to confirm the single oval canal. (c) Access opening was done. (d) Working length was confirmed radiographically. (e) Teeth were mounted on wax and CBCT was performed. (f) Each tooth was fixed in the rubber plug of the glass vial with cyanoacrylate. (g) Root canal instrumentation was done. (h) Eppendorf tubes showing apically extruded debris. (i) CBCT was done after instrumentation and the remaining dentin thickness was calculated using Invivo software (Dexis, Quakertown, PA). (j) Canals were dried, and obturation was done. (k) Post-endodontic restoration was done with composite resin. (l) Each tooth was embedded in a putty impression material and a continuous load was delivered through a universal testing machine until fracture occurred. CBCT, cone beam CT