Can Type of Instrumentation and Activation of the Final Irrigant Improve the Obturation Quality in Oval Root Canals? A Push-Out Bond Strength Study.

Ajinkya M Pawar,Bhaggyashri A Pawar,Anuj Bhardwaj,Anda Kfir,Dian Agustin Wahjuningrun,Alexander Maniangat Luke,Yeyen Yohana,Zvi Metzger

doi:10.3390/biology11010059

Abstract

Simple SummaryThe complete instrumentation of oval root canals remains practically unattainable. The majority of studies show that shaping oval, flat, and irregularly shaped canals is challenging, with more than half of the root canal area remaining unaltered. Furthermore, both rotary and reciprocating files compact hard tissue debris into the isthmus areas and buccal and/or lingual recesses of oval canals, impairing debridement and filling. In addition, one of the most essential variables in assessing the success of endodontic therapy is the adhesion of root canal filling material to dentin.To appraise the outcome of file systems and activation of the final irrigant on the push-out bond strength of root fillings in oval canals. Single-rooted mandibular premolars (n = 180) with oval canals were divided into three groups (n = 60) for instrumentation: ProTaper Next (PTN), WaveOne (WO), and Self-adjusting File (SAF). The specimens were further divided into subgroups (n = 20) and subjected to final irrigation with activation by EndoActivator or passive ultrasonic irrigation or without activation. Then, the specimens were again subdivided (n = 10) and obturated with gutta-percha and AH Plus (GP-AH) or C-Point with EndoSequence bioceramic sealer (C-EBC). One-millimeter-thick horizontal slices were cut from the apical third of the root, 5 mm from the apex, and subjected to push-out bond strength (BS) testing. Specimens for which SAF was used exhibited higher BS values than those for which PTN or WO was used (p < 0.05). Activation of the final irrigation did not affect the BS of the root fillings. Root fillings made of C-EBC presented a higher BS than those made of GP-AH (p < 0.05). Adhesive failure was more common with specimens instrumented using PTN and WO. Root canals instrumented with SAF, showed the highest bond strength values for both root filling materials. The C-EBC produced significantly higher bond strength values than those of the GP-AH.

Highlights

Clinical endodontics is flooded with an abundance of innovations in terms of instrument design, metallurgy, and kinematics [1]
The analysis of the data by the three-way analysis of variance (ANOVA) manifested that the instrumentation protocol and type of root filling had a significant impact on the dislocation resistance of both filling materials (p < 0.05), while the bond strength was unaffected by the irrigant activation technique (p > 0.05)
Specimens that were subjected to the ProTaper Next (PTN) or WO instrumentation showed lower bond strength values than the values of those subjected to the Self-adjusting File (SAF) system (Group 3), which served as a positive control

Summary

Introduction

Clinical endodontics is flooded with an abundance of innovations in terms of instrument design, metallurgy, and kinematics [1]. Most file systems can productively clean canals with a round cross section. The use of rotary or reciprocating file systems may actively push and accumulate debris in the uninstrumented anatomical eccentricities of root canal systems [2,3,4]. It has been suggested that irrigant activation with either sonic or ultrasonic devices may overcome this problem and remove any tissue or debris remaining in areas untouched by the rotating file [5]. Such remaining debris may further impede the goal of a well-filled and well-sealed root canal system [4]

Methods

Discussion

Conclusion