Cleaning and Shaping Oval Canals with 3 Instrumentation Systems: A Correlative Micro–computed Tomographic and Histologic Study

doi:10.1016/j.joen.2017.06.032

Journal of Endodontics

Volume 43, Issue 11, November 2017, Pages 1878-1884

https://doi.org/10.1016/j.joen.2017.06.032 Get rights and content

Highlights

•
The mean unprepared apical areas ranged from 10% (SAF) to 18% (XP-endo Shaper).
•
SAF exhibited less unprepared areas than XP-endo Shaper in the apical canal.
•
In the full canal length, the amount of prepared walls was similar for the 3 systems.
•
The 3 instrument systems displayed similar behavior in terms of cleaning.

Abstract

Introduction

The present study evaluated the cleaning and shaping ability of 3 instrumentation systems in oval canals of extracted vital teeth using a correlative analytic approach.

Methods

Oval distal canals from 33 freshly extracted mandibular molars with pulp vitality were scanned by micro–computed tomographic (micro-CT) imaging for sample selection. Specimens matched by anatomic similarities were distributed into 3 experimental groups according to the instrument system to be evaluated: the Self-Adjusting File (SAF; ReDentNOVA, Ra'anana, Israel), TRUShape (Dentsply Sirona, Tulsa, OK), and XP-endo Shaper (FKG Dentaire, La Chaux-de-Fonds, Switzerland). The irrigant was 5.25% sodium hypochlorite heated at 37°C. After rescanning with micro-CT imaging, the unprepared surface areas were identified, measured, and then histologically evaluated for the amount of pulp remnants in each root third.

Results

When the apical 4-mm canal segment was evaluated, the SAF exhibited significantly less unprepared areas than the XP-endo Shaper (P < .05), and there were no significant differences for the other comparisons (P > .05). Analysis of the full canal length showed no statistically significant differences between the 3 tested systems (P > .05). Likewise, the tested systems did not differ significantly in cleaning the unprepared walls (P > .05).

Conclusions

There was no significant difference in the amount of unprepared surface areas between the 3 instrument systems, except for the comparison between the SAF and XP-endo Shaper in the apical 4-mm segment. None of them prepared 100% of the root canal walls. The cleaning ability of the 3 systems was similar.

Section snippets

Specimen Selection and Preparation

The study protocol was approved by the institutional ethics committee of human research. Thirty-three vital human mandibular molars freshly extracted for reasons not related to this study were selected. Immediately after extraction, teeth were stored in 10% buffered neutral formalin. Pulp vitality was confirmed by the presence of bulk soft tissue in the pulp chamber after access preparation and later by histologic analysis. The inclusion criteria considered only distal roots with a single canal

Micro-CT Imaging

There were no significant differences between groups for specimen length, canal volume, and canal surface area before preparation (P > .05). The mean specimen lengths for the SAF, X-endo Shaper, and TruShape groups were 11.1 mm, 10.6 mm, and 10.3 mm, respectively. The volume and surface area of the distal root canals were significantly increased after instrumentation with the 3 systems (P < .01). There were no significant differences between groups (P > .05).

In the apical 4-mm segment, the mean

Discussion

This study used an innovative correlative micro-CT/histologic approach to evaluate the cleaning and shaping ability of 3 instrument systems in oval distal canals of vital mandibular molars. The 3 systems have been specially devised to reach larger extensions of the canal walls and perform better in anatomically complex canals than conventional instruments. The present findings showed that the mean amount of areas that remained untouched by the 3 instrument systems ranged from 9.85%–17.77% in

Acknowledgments

Supported by grants from Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ) and Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), Brazilian Governmental Institutions.

The authors thank FKG Dentaire for providing the XP-endo Shaper instruments and ReDentNOVA for providing the SAF instruments and EndoStation equipment.

The authors deny any conflicts of interest related to this study.

References (26)

Y.T. Jou et al.
Endodontic working width: current concepts and techniques
Dent Clin North Am
(2004)
M.K. Wu et al.
Prevalence and extent of long oval canals in the apical third
Oral Surg Oral Med Oral Pathol Oral Radiol Endod
(2000)
F. Paqué et al.
Preparation of oval-shaped root canals in mandibular molars using nickel-titanium rotary instruments: a micro-computed tomography study
J Endod
(2010)
J.F. Siqueira et al.
Correlative bacteriologic and micro-computed tomographic analysis of mandibular molar mesial canals prepared by self-adjusting file, Reciproc, and Twisted File systems
J Endod
(2013)
O.A. Peters et al.
A micro-computed tomographic assessment of root canal preparation with a novel instrument, TRUShape, in mesial roots of mandibular molars
J Endod
(2015)
M.A. Versiani et al.
Flat-oval root canal preparation with self-adjusting file instrument: a micro-computed tomography study
J Endod
(2011)
O.A. Peters et al.
Root canal preparation of maxillary molars with the self-adjusting file: a micro-computed tomography study
J Endod
(2011)
F. Paqué et al.
Micro-computed tomography evaluation of the preparation of long oval root canals in mandibular molars with the self-adjusting file
J Endod
(2011)
Z. Metzger et al.
The quality of root canal preparation and root canal obturation in canals treated with rotary versus self-adjusting files: a three-dimensional micro-computed tomographic study
J Endod
(2010)
Z. Metzger et al.
The self-adjusting file (SAF). Part 1: respecting the root canal anatomy–a new concept of endodontic files and its implementation
J Endod
(2010)

J.F. Siqueira et al.

Ability of chemomechanical preparation with either rotary instruments or self-adjusting file to disinfect oval-shaped root canals

J Endod

(2010)

G. De-Deus et al.

The self-adjusting file optimizes debridement quality in oval-shaped root canals

J Endod

(2011)

Z. Metzger et al.

The self-adjusting file (SAF). Part 3: removal of debris and smear layer - a scanning electron microscope study

J Endod

(2010)

Cited by (93)

Accumulated Hard Tissue Debris and Root Canal Shaping Profiles Following Instrumentation with Gentlefile, One Curve, and Reciproc Blue
2023, Journal of Endodontics
This laboratory study aimed to evaluate the accumulated hard tissue debris (AHTD) and shaping performance following root canal instrumentation with a novel stainless steel rotary system (Gentlefile; MedicNRG, Kibbutz Afikim, Israel) compared with two single-file nickel-titanium instruments of different kinematics through micro–computed tomography (micro-CT) analysis.
Thirty isthmus-containing mesial roots of human mandibular molars with a curvature of 15°–35° were scanned with micro-CT at an isotropic resolution of 12 μm and randomly assigned to three groups (n = 10) according to the instruments used for canal preparation: Gentlefile (GF; #23/.04), One Curve (OC; #25/.06; Micro-Mega, Besancon, France), and Reciproc Blue R25 (RB; #25/.08; VDW, Munich, Germany). The AHTD, unprepared canal surface area, volume changes, surface area changes, and transportation were evaluated by comparing preoperative and postoperative micro-CT images. In addition, the time required for canal preparation was recorded. Data were statistically analyzed using the one-way analysis of variance (ANOVA) test or the Kruskal-Wallis test at a significance level of 5%.
No significant differences were observed in the percentage of AHTD or in the unprepared canal surface area between the three groups (P > .05). The RB group demonstrated a significantly greater percentage increase in volume and surface area than the GF group (P < .05). The GF and OC groups showed significantly less transportation at 3 mm from the apex than the RB group (P < .001). The OC group required significantly less time for instrumentation than the RB and GF groups (P < .05).
Instrumentation with GF (#23/.04), OC, and RB yielded similar levels of AHTD and unprepared surface area in isthmus-containing curved canals. GF achieved this with less dentin removal and apical transportation, at the expense of a longer preparation time.
Disinfection and Shaping of Vertucci Class II Root Canals after Preparation with Two Instrument Systems and Supplementary Ultrasonic Activation of Sodium Hypochlorite
2023, Journal of Endodontics
This study compared disinfection and shaping after root canal preparation with either XP-endo Shaper or TruNatomy instrument systems, supplemented by ultrasonic activation of sodium hypochlorite (NaOCl) with either stainless-steel (SS) or nickel-titanium (NiTi) inserts.
Mesial roots from mandibular molars with Vertucci class II configuration were divided into 2 groups (n = 24) based on anatomically paired micro-computed tomography (micro-CT) analyses. Pre and postpreparation micro-CT scans were obtained to evaluate the shaping performance. The canals were contaminated with a mixed bacterial culture for 30 days and then subjected to preparation with either XP-endo Shaper or TruNatomy instruments using NaOCl irrigation. Supplementary ultrasonic activation of NaOCl was conducted using either an SS (TruNatomy group) or NiTi (XP-endo Shaper group) insert. Bacteriological samples were taken from the canals before preparation (S1), after preparation (S2), and after the supplementary approach (S3). Bacterial reduction was evaluated using a quantitative real-time polymerase chain reaction.
Preparation with both instrument systems significantly reduced bacterial counts (P < .01). After preparation, 36% (TruNatomy) and 35% (XP-endo Shaper) were negative for bacteria. These values increased to 59% and 65% after ultrasonic activation with the SS and NiTi inserts, respectively. The quantitative data in S2 showed that XP-endo Shaper promoted a significantly higher bacterial reduction than TruNatomy (P < .05). No significant intragroup differences were observed after ultrasonic activation (P > .05), probably because the SS insert promoted a significantly higher S2-to-S3 reduction than the NiTi insert (P < .01). Micro-CT analysis revealed no significant differences in the unprepared areas between the groups (P > .05).
The XP-endo Shaper caused a significantly higher bacterial reduction than TruNatomy in Vertucci class II canals. Better antibacterial results after ultrasonic activation were observed for the SS ultrasonic inserts than for the NiTi inserts.
Influence of pecking frequency at working length on the volume of apically extruded debris: A micro-computed tomography analysis
2022, Journal of Dental Sciences
Citation Excerpt :
Reciproc Blue (RB) and WaveOne Gold (WOG) are two popular single-file systems working with reciprocating motion.7 Recently introduced XP-endo Shaper (XPS) is specifically designed to overcome the challenge of irregular root canals, including oval-shaped canals.12,13 To date, the debris extruded by them in oval-shaped and curved canals remains unclear.
There is no consensus to date on how many repetitive pecking motions at working length (WL) should be regarded as optimal during instrumentation. Therefore, this study aimed to evaluate the effect of pecking frequency at WL on the volume of apically extruded debris using three single-file systems in curved, oval-shaped canals.
Forty-five single-rooted mandibular premolars with curved, oval-shaped canals were prescanned by micro-computed tomography, anatomically paired-matched, and randomly divided among three groups (n = 15 each): Reciproc Blue (RB), WaveOne Gold (WOG) and XP-endo Shaper (XPS). Samples were embedded in agarose gel to collect extruded debris. After preparation to the WL, each sample was rescanned after one, two, four, 10, and 20 pecking motions at WL, respectively. The debris volume was innovatively calculated by a modification of an existing method using micro-computed tomography. The apical preparation size was also measured. Data were compared using a two-way repeated-measures analysis of variance.
All single-file systems extruded debris apically, irrespective of the pecking frequency at WL. The extruded debris volume correlated positively with the minor foramen size (P < 0.05); both increased with pecking frequency for each single-file system (P < 0.05). The minor foramen size corresponded to the instrument tip size when reaching the WL once.
To produce less debris extrusion and obtain a predictable foramen size corresponding to the instrument tip size, a single pecking motion may be preferred when using single-file systems. Caution should be exercised when applying the current results to clinical situations.
Influence of the Number of Pecking Motions at Working Length on the Shaping Ability of Single-file Systems in Long Oval-shaped Curved Canals
2022, Journal of Endodontics
The present study compared the effect of the number of pecking motions at the working length (WL) on the shaping ability of single-file systems in long oval-shaped curved root canals.
Single-rooted mandibular premolars with long oval-shaped curved canals (25°–35°) were prescanned using micro–computed tomographic imaging, anatomically paired, and randomly divided into 3 groups (n = 15): XP-endo Shaper (XPS; FKG Dentaire, La Chaux-de-Fonds, Switzerland), Reciproc Blue (RB; VDW, Munich, Germany), and WaveOne Gold (WOG; Dentsply Sirona, Ballaigues, Switzerland). After preparation to the WL, each specimen underwent 1, 2, 4, 10, or 20 pecking motions to the WL and was rescanned. Morphologic parameters were measured and analyzed using a 2-factor repeated measures analysis of variance and the Scheirer-Ray-Hare test.
The minor apical diameter and percentage increase in canal volume increased with the number of pecking motions, whereas the percentage of unprepared canal surface area decreased (P < .05). The mean minor diameters (in mm) at D0 varied between 0.29 and 0.35 after 4 pecking motions with the RB and WOG systems and between 0.35 and 0.36 after 10 pecking motions with the XPS system. No significant differences in canal transportation or centering ratio were observed among the groups at the levels of canal curvature and canal thirds (P > .05).
Increasing the number of pecking motions improves the cutting efficacy of single-file systems without adversely altering the anatomic characteristics of oval-shaped curved canals. No more than 4 pecking motions for the RB and WOG systems and 10 pecking motions for the XPS system appear to be acceptable for the shaping of these difficult to clean root canals.
Novel laser activated photoacoustic streaming for removing pulp remnants from round root canals after single file reciprocating instrumentation
2022, Photodiagnosis and Photodynamic Therapy
Citation Excerpt :
Additionally, after single-file instrumentation, approximately 18% of untouched intracanal areas are left in premolars, of which 10% are in the apical region [3]. To enhance the disinfection these regions, new instruments that adapt to complex intracanal anatomy and improved activated irrigation techniques have been developed and evaluated [8,27,28]. In this study, we evaluated the efficacy of a new Er:YAG laser activated irrigation technique, the SWEEPS protocol, for the removal of the pulp tissue from round canals of premolars after single-file reciprocating instrumentation.
: This study evaluated the efficacy of a new laser-assisted irrigation system, the shock wave enhanced emission photo-acoustic streaming (SWEEPS) technique in removing pulp tissue from single-rooted premolars.
: Freshly extracted mandibular premolars with round root canals (n = 40), scanned using cone beam computed tomography, were randomly divided into control and four experimental (according to the irrigation technique used) groups (n = 8/group). Groups 1, 2, and 3 were instrumented using Reciproc Blue (RB25/0.06) followed by final irrigation protocol (FIP), activated by SWEEPS, ultrasonically activated irrigation (UAI), and conventional irrigation (CI), respectively. In these groups, 7 mL 3% NaOCl in total was used during instrumentation; for FIP, 3% NaOCl (60 s), ethylenediaminotetraacetic acid (60 s), and 3% NaOCl (30 s). In group 4, SWEEPS activation of 3% NaOCl for 6 × 30 s alone was performed. The untreated control group specimens were processed for histological evaluation of remaining pulp tissue (RPT) in each canal third. The results were analyzed using the Mann-Whitney U test (α = 0.05).
: Significant differences were observed between the control group and the experimental groups (p<0.05). In the middle third, the UIA and SWEEPS showed similar efficacy (p = 0.171), superior to CI and SWEEPS without instrumentation (p<0.05). In the apical third, SWEEPS was the most efficient (p = 0.002), and UIA and CI showed no difference (p = 0.643).
: SWEEPS was superior to UIA and CI in removing RPT in the apical region of round canals after single instrument root canal preparation; SWEEPS without instrumentation was inefficient in removing pulp tissue.
Characterisation of deformed or separated nickel-titanium retreatment instruments after clinical use - A multicentre experience: Defect profiles of clinically-used retreatment instruments
2022, Journal of Dentistry
The present study examined the defect characteristics of clinically-used, discarded nickel titanium rotary retreatment instruments and analysed the impact of clinical use on their metallurgical properties.
92 XP-endo Shaper (XPS; FKG Dentaire) and 20 XP-endo Finisher (XPFR; FKG Dentaire) instruments with structural deformation or separation were collected after retreatment from four endodontic clinics over a 20-month period. The types of defects and their relative locations were recorded. The lateral and fractured surfaces of the separated instruments were examined with scanning electron microscopy. Differential scanning calorimetry was used to investigate the thermal behaviour of new, deformed and fractured instruments.
77 (84%) XPS and 4 (20%) XPFR had an area with structural change while 15 (16%) XPS and 16 (80%) XPFR were fractured. All unfractured, deformed XPFR showed unwinding close to the coronal end of the flute. Fractures in XPS and XPFR were often close to the coronal end of the flutes or the expanding segments of the insruments. Most of the XPS fractures were torsional failure (67%) while XPFR failed predominantly by cyclic fatigue (81%). The austenite-finishing temperature of XPFR (40 °C) was higher than that of XPS (35 °C). Both XPS and XPFR exhibited 2-stage phase transformations.
Torsional failure was more prevalent in XPS instruments and fatigue failure was more prevalent in XPFR instruments. amongst the investigated instruments, XPFR were more likely to separate without warning whereas XPS frequently exhibited plastic deformation. The latter may be used as a pre-separation forewarning sign during clinical retreatment.
The failure mode of XP-endo Shaper and XP-endo Finisher used clinically for retreatment appeared to be different. Plastic deformation, the forewarning sign of instrument seaparation, occurs when XP-endo instruments are used for retreatment.

View all citing articles on Scopus

View full text

Basic ResearchCleaning and Shaping Oval Canals with 3 Instrumentation Systems: A Correlative Micro–computed Tomographic and Histologic Study

Highlights

Abstract

Introduction

Methods

Results

Conclusions

Section snippets

Specimen Selection and Preparation

Micro-CT Imaging

Discussion

Acknowledgments

Dent Clin North Am

Oral Surg Oral Med Oral Pathol Oral Radiol Endod

J Endod

J Endod

J Endod

J Endod

J Endod

J Endod

J Endod

J Endod

J Endod

J Endod

J Endod

Basic Research
Cleaning and Shaping Oval Canals with 3 Instrumentation Systems: A Correlative Micro–computed Tomographic and Histologic Study