Shaping ability of XP‐endo Shaper and ProTaper Next in long oval‐shaped canals: a micro‐computed tomography study

Shaping Ability of TRUShape and XP-endo Shaper in C-Shaped Canals Using 3D-Printed Replicas: A Micro-CT Study

OBJECTIVE

 This study compared the shaping ability of TRUShape and XP-endo Shaper systems on C-shaped root canals replicas using microcomputed tomography (micro-CT).

MATERIAL AND METHODS

 Thirty three-dimensional replicas based on a mandibular second molar classified as C1 type I C-shaped canal were randomly divided into two groups (n = 15): TRUShape (G.TRU) and XP-endo Shaper (G.XP) and instrumented with each system according to the manufacturer's instructions. Changes in volume and surface and the unprepared area of the root canal were measured by scanning on micro-CT before and after instrumentation.

RESULTS

 The unprepared areas were 39% in the G.TRU and 43% in the G.XP group with no significant difference between them (p > 0.05), but both the tested systems left a high percentage of unprepared root canal walls of C-shaped root canals.

CONCLUSION

 TRUShape and XP-endo Shaper showed a high rate of unprepared areas with similar results after C-shaped root canals replicas for root canal preparation.

Comparative evaluation of remaining dentin thickness, canal centering ability and apical deformity between ProFit S3 and Protaper gold - A nano CT study

Purpose

For the root canal treatment to be successful, the root canal system must be cleaned and shaped, and must be gradually widened from the apical to the coronal region in order to preserve dentin thickness. ProFit S3 (Profit Dental, India) patented rotary file with variable taper design preserves dentin. The study employs ultra-high-resolution nano-computed tomography to assess the volumetric changes of two new rotary files in permanent mandibular premolars.

Materials and methods

Based on inclusion and exclusion criteria, this in-vitro investigation used extracted premolars. Before the pre-operative scan, samples were made and the working length was determined using a high-precision nano-CT (SkyScan 2214, Bruker, Kontich, Belgium). A single skilled pediatric dentist used ProFit S3 (Profit Dental, India) and Protaper Gold (PTG; Dentsply, Tulsa Dental Specialties, Tulsa, OK, USA) to prepare the canals. Post-op scans were similar to pre-ops. For 3D root canal visualization and analysis, NRecon software was used to rebuild images.

Results

Profit S3 has a mean value of 0.65500 and Protaper gold 1.38800, indicating a significant range. Protaper gold followed Profit S3 in canal volume differential. The two rotating file systems differed significantly (p 0.05). ProFit S3 maintained mesiodistal and buccolingual dentin thickness at 4 mm, 8 mm, and 12 mm, followed by Protaper Gold.

Conclusions

ProFit S3 exhibited the lowest mean canal volume difference compared to Protaper gold. Unlike Protaper Gold, ProFit S3 offers a variable taper design that preserves root canal anatomy, peri cervical dentin, and dentin thickness.

Shaping ability of three heat-treated NiTi systems in Vertucci's type III root canals of mandibular incisors: An ex vivo study

Introduction

The anatomical configuration classified as Vertucci's type III is described as the second most prevalent in mandibular incisors.

Methods

Thirty-six Vertucci's type III mandibular incisors were evaluated by micro-computed tomography (micro-CT) and divided into 3 groups (n = 12) according to the root canal preparation protocol (HyFlex CM [HCM], HyFlex EDM [HEDM], and Sequence Rotary File [SRF]). The teeth were scanned before and after performing 0.25 mm and 0.40 mm apical diameter preparations. The canal volume, dentin thickness, percentage of accumulated debris and untouched canal areas, transportation, and centering ability were measured. The data were statistically analyzed by ANOVA, Tukey, Kruskal-Wallis, and Dunn tests (P < 0.05).

Results

The volume increase was more evident in the apical third. After 0.40 mm preparation, the SRF system provided a higher reduction (P < 0.05) in dentin thickness on the buccal surface 1 mm from the apex. There was higher canal transportation in the bucco-lingual direction. The 0.40 mm apical preparation reduced the percentage of untouched canal areas. The apical third had the highest percentage of untouched canal areas. The cervical third had the lowest volume of accumulated debris.

Conclusions

Increasing the apical preparation to a diameter of 0.40 mm with the HCM, HEDM, and SRF systems in Vertucci's type III root canals of mandibular incisors proved to be safe and effective, reducing untouched canal areas.

Clinical relevance

Root flattening can be intense to the point of generating a root canal bifurcation. Despite the decrease in the root canal diameter, a greater enlargement of the apical region is necessary and safe.

The Complexity of the Root Canal Anatomy and Its Influence on Root Canal Debridement in the Apical Region: A Review

The main goal of root canal treatment is to eliminate the infection in the complex root canal system for the long-term preservation of a functional tooth. Proper debridement of the root canal system, especially in the apical portion, is essential for successful root canal treatment. The complexity of the canal anatomy in the apical region plays a crucial role in reducing the microbial load. Therefore, clinicians must have a thorough knowledge of the anatomy of the root canal system and its variations, especially in the apical portion. Root canal configurations in cross-section have been classified as round, oval, long oval, flattened, or irregularly shaped. Treating oval, long oval, flattened, or irregularly shaped canals is challenging and should be approached differently than a circular canal. Recognizing the root canal shape and apical anatomy determines the different strategies to be used in cleaning, shaping, and obturation to achieve the best result of root canal treatment. The recent development of the instrumentation system improves the treatment outcome for clinicians and patients. This review aimed to discuss the definition, prevalence, and instrumentation for cleaning and shaping in the apical area with the complexity of root canal systems. Therefore, with the aid of this review, we can better understand the variations in the anatomy of the root canal, especially at the apical portion.

Cleaning and Disinfecting Oval-Shaped Root Canals: Ex Vivo Evaluation of Three Rotary Instrumentation Systems with Passive Ultrasonic Irrigation

Background and Objectives: Successful root canal treatment depends on the thorough removal of biofilms through chemomechanical preparation. This study aimed to investigate and compare the cleaning and disinfecting efficiency of oval-shaped root canals using XP-endo Shaper (XPS), ProTaper Next (PTN), and HyFlex CM (HCM) in combination with passive ultrasonic irrigation (PUI). Materials and Methods: Ninety extracted teeth were contaminated and randomly divided into three groups: XPS, PTN, and HCM. Each group was assigned to three subgroups: subgroup A (sterile saline), subgroup B (3% sodium hypochlorite and 17% ethylenediaminetetraacetic acid), and subgroup C (3% sodium hypochlorite, 17% ethylenediaminetetraacetic acid, and PUI). Bacterial sampling was conducted both from baseline samples and samples after chemomechanical preparation. Scanning electron microscopy (SEM) was used to evaluate the residue bacterial biofilms, hard tissue debris, and smear layers on the buccolingual walls of oval-shaped root canals. Results: When combined with sterile saline, XPS demonstrated a higher reduction of bacterial counts and was more effective in eradicating Enterococcus faecalis in the middle third of the canals compared to the other instruments (p < 0.05). Additionally, when used with antimicrobial irrigants, XPS was more effective in disinfecting the coronal third of the canals than the other instruments (p < 0.05). Furthermore, XPS reduced hard tissue debris more effectively in the middle third of canals than in the apical third (p < 0.05). Conclusions: XPS outperforms PTN and HCM in disinfecting oval-shaped root canals. Despite the fact that combining XPS and PUI improves cleaning and disinfecting, removing hard tissue debris from the critical apical area remains challenging.

Analysis of Shaping Abilities of Rotary File Systems in Oval Canals with Moderate Root Curvature: A Randomized Controlled Ex Vivo Study

AIM

The purpose of this study was to evaluate and compare the canal transportation tendencies and centering ability of the TruNatomy shaper (TN) and XP-endo shaper (XPS) rotary systems in oval-shaped canals with moderate root curvature (15°-25°), using cone-beam computed tomography (CBCT) imaging.

MATERIALS AND METHODS

Sixty single-rooted permanent human teeth were chosen after considering the inclusion and exclusion criteria. The teeth were divided into two groups (n = 30). The test group was instrumented with TN files and the other with XPS according to manufacturer's instructions. CBCT images were taken before and after instrumentation to record the root canal distances from mesial, distal, buccal, and lingual borders of the root at 3, 5, and 7 mm distances from the root apex using a specific formula. Statistical analysis was done using the Statistical Package for the Social Sciences software program, version 20.0. The data were analyzed using the unpaired t test.

RESULTS

Both TN and XPS were safe for use in oval-shaped canals with moderate root curvature. However, the XPS showed higher buccolingual transportation as compared with TN at 3 mm from the apex and higher mesiodistal transportation at 3 and 5 mm levels from the apex as compared with TN.

CONCLUSION

Canal transportation has been detected in both systems; however, the values obtained were within the safe range (<0.3 mm). Overall, no significant difference was observed between TN and XPS (p > 0.05) in their canal transportation tendencies and centering ability.

CLINICAL SIGNIFICANCE

The study assesses the canal centering and transportation tendencies of the recently launched TN rotary system in extracted teeth with a combination of morphologies. The findings of the study are significant clinically as minimum transportation of the canal, minimal dentin removal, efficient disinfection, and three-dimensional obturation of the root canal are considered important factors in deciding the prognosis of endodontic therapy.

A micro-computed tomographic analysis of the root canal systems in the permanent mandibular incisors in a Chinese population

BACKGROUND

Comprehensive understanding of the root canal system complexity is critical important for successful root canal therapy. A double root canal system may be present in permanent mandibular incisors with a variable incidence in different ethnic populations. Ignorance or improper management of this canal variation can lead to treatment failure. This in vitro study aimed to identify the anatomic features of root canal systems in the mandibular incisors in a Chinese population by using micro-CT.

METHODS

A total of 106 permanent mandibular incisors (53 central incisors and 53 lateral incisors) were collected from a native Chinese population. The teeth were scanned by a micro-CT scanner and then reconstructed three-dimensionally. The canal configurations were detected by Vertucci's classification, and the number and location of the accessory canals were also identified. The long (D) and short diameters (d) of the main and accessory canals were measured and D/d ratio was calculated at different root levels (cemento-enamel junction [CEJ] level, mid-root level and 1, 2, 3 and 4 mm from the apex). The root canal curvatures in the double-canaled mandibular incisors were measured at the proximal view by using modified Schneider's method. Chi-square test or Fisher's exact test was used for comparison of occurrence rates. Comparison of means from multiple groups was performed by using one-way ANOVA and LSD post-hoc test.

RESULTS

In regard to the occurrence of double root canals, gender difference was neither detected in the mandibular central (16.0% [male] vs 14.3% [female]; p = 0.862), nor in the mandibular lateral incisors (26.9% [male] vs 33.3% [female]; p = 0.611). Age group difference was also not detected in the mandibular central (p = 0.717) and lateral incisors (p = 0.521). The incidence of double root canals was 15.1% (8/53) in the central incisors, and 30.2% (16/53) in the lateral incisors, but the difference did not reach statistical significance (p = 0.063). The most frequent non-single canal type was the type III (1-2-1) (18.9% [20/106]), and the other types identified included 1 case of type II (2-1) and 3 cases of type V (1-2). The incidence of accessory canals was 17.9% (19/106), with a mean level of 1.92 ± 1.19 mm from the apex. The frequency of long-oval (2 ≤ D/d < 4) and flattened canals (D/d ≥ 4), as well as the mean value of D, d and D/d ratio increased from the apical 1 mm to the apical 4 mm level (the D/d ratio increased from 1.9 to 2.9 for the single canals, from 1.4 to 3.3 for the buccal canals and from 1.2 to 2.3 for the lingual canals), and the D/d ratio reached the peak at the mid-root level. Double curvatures were detected in 33.3% (8/24) of the buccal canals and 37.5% (9/24) of the lingual canals, and the difference has no statistical significance (p = 0.063). The degrees of the primary curvatures were 21.5 ± 7.1 degrees for the buccal and 30.1 ± 9.2 degrees for the lingual canals, and the degrees of secondary curvatures were 27.0 ± 11.4 degrees for the buccal and 30.5 ± 12.5 degrees for the lingual canals in the double curvatures. The degrees of the single curvatures were 14.2 ± 6.3 degrees for the buccal and 15.6 ± 6.0 degrees for the lingual canals. Significant difference was detected among above 6 groups of canal curvatures (p = 0.000), and severe curvatures (≥ 20 degrees) were more frequently detected in the double curved canals.

CONCLUSIONS

Double-canaled mandibular incisors were not uncommon in the Chinese population, and type 1-2-1 was the most frequent non-single canal type. Gender and age did not significantly impact the occurrence of a second canal in mandibular incisors. Long-oval and flattened canals were very common at different root levels and their incidence increased from apex to the mid-root level. Severe curvatures were frequently detected in the double canal systems, especially in those canals with double curvatures.

Optimization of automated preparation of long oval-shaped root canals using supplementary instrumentation

This study compared the preparation of long oval-shaped root canals using WaveOne Gold and XP-endo Shaper systems, both supplemented or not with manual instrumentation. Twenty-four long oval-shaped canals of mandibular incisors were distributed into two groups according to the instrumentation: WaveOne Gold Primary or XP-endo Shaper systems. All root canals were manually instrumented with a size 25 K-file after automated preparation. The specimens were scanned by using a micro-CT device (17.42 µm) before and after automated preparation and manual instrumentation. The increased surface of the root canal and the percentage of untouched areas were assessed. Both WaveOne Gold and XP-endo Shaper systems increased the root canal surface and had similar untouched areas (p>0.05). Supplementary instrumentation increased the surface of the root canal and decreased the untouched walls (p<0.05). WaveOne Gold and XP-endo Shaper systems provided a similar preparation of long oval-shaped canals and manual instrumentation improved their preparation.

Shaping ability of WaveOne Gold and OneReci by using two apical sizes: a micro-computed tomographic assessment

Backround

OneReci (MicroMega, Besançon, France) is a recently introduced single-file reciprocating system with scarce information revealed on its shaping ability. This study aimed to compare the shaping abilities of OneReci and a well-documented single-file reciprocating system WaveOne Gold (WOG; Dentsply Maillefer, Ballaigues, Switzerland) and evaluate the effect of increased apical enlargement on the preparation quality, using micro-computed tomography (micro-CT).

Methods

After an initial micro-CT scanning, twenty mesial root canals of mandibular molars were anatomically matched. The canals were assigned to two experimental groups (n = 10), using OneReci or WOG in different canals of the same root. The glide paths were created, and root canals were prepared twice, using size 25 and 35 instruments of the systems, respectively. The specimens were scanned with micro-CT after each preparation. The increase in canal volume, amount of dentin removal, unprepared root canal surface, canal transportation, centering ratio and preparation times were assessed. The data were analysed with independent sample t-tests, variance analyses, Friedman and Mann-Whitney U tests. The significance level was set at 5%.

Results

Each preparation increased the canal volume and dentin removal while decreasing the unprepared root surface. The difference between the systems became significant after preparation with size 35 instruments (p < 0.05). Regarding canal transportation and centering ratio, the difference was insignificant (p > 0.05). The first preparation step (glide path + size 25 instrument) was significantly faster in the OneReci group (p < 0.05).

Conclusions

Preparation with size 25 instruments of the systems appeared to be safe with similar shaping performances. Larger apical preparation promoted significantly higher dentin removal, volume increase, and prepared surface area in WOG.

Shaping outcome of ProTaper NEXT for root canal preparation in mandibular incisors: a micro-CT study

Background

Relatively high incidence of single canals with oval or round shape were observed in human mandibular incisors. In order to investigate the influence of the root canal morphology on root canal preparation, the shaping outcome of ProTaper NEXT in oval and round canals of mandibular incisors were evaluated by using micro-computed tomography (micro-CT) analysis.

Methods

This experiment was approved by the School Medical Ethics Committee. The sample size calculation was conducted using G*Power software. Intact mandibular incisors with a single canal were selected. Oval canals (2 < aspect ratio (AR) ≤ 4) and round canals (AR ≤ 2) were pair-matched according to canal length, and assigned to two experimental groups (13 per group). ProTaper NEXT was used for root canal preparation for both groups. Untouched canal wall (UCW), root canal morphological parameters and three-dimensional (3D) dentin thickness were evaluated in the entire root canal and each canal third after micro-CT scanning. Statistical analysis: Data were collected and analyzed with Mann–Whitney test and Friedman test using SPSS statistics software 25 (P < 0.05). Additionally, correlations of UCW area with canal morphological parameters were also investigated.

Results

After root canal preparation, no significant difference was observed in all analyzed parameters in the apical third between oval and round canal groups (P > 0.05). In the coronal two thirds of the canal, the post-operative structure model index (SMI), form factor and roundness were significantly increased, while the AR was significantly decreased in both groups (P < 0.05). In addition, in the coronal two thirds, significantly more UCW and higher UCWΔ% was observed in oval canal group (P < 0.05). Furthermore, UCW correlated very strongly to canal major diameter (0.924) and initial volume (0.938), and strongly to canal form factor (− 0.724), minor diameter (0.799) and canal area (0.882). Proximal dentin wall was associated with significantly thinner pre-operative dentin thickness and higher amount of dentin removal after root canal preparation in both oval and round canal groups.

Conclusions

(1) Both types of canals were more conical after root canal preparation, but oval root canals tend to leave more UCW area than round canals in the coronal two thirds of mandibular incisors, which contributes to the challenge for endodontic infection control. (2) Root canal preparation usually results in excessive dentin removal in the proximal dentin wall comparing with buccal and lingual walls in both types of canals of mandibular incisors.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12903-022-02335-7.

Effect of Different Downward Loads on Canal Centering Ability, Vertical Force, and Torque Generation during Nickel-Titanium Rotary Instrumentation

This study aimed to examine how downward loads influence the torque/force and shaping outcome of ProTaper NEXT (PTN) rotary instrumentation. PTN X1, X2, and X3 were used to prepare J-shaped resin canals employing a load-controlled automated instrumentation and torque/force measuring device. Depending on the torque values, the handpiece was programmed to move as follows: up and down; downward at a preset downward load of 1 N, 2 N or 3 N (Group 1N, 2N, and 3N, respectively; each n = 10); or upward. The torque/force values and instrumentation time were recorded, and the canal centering ratio was calculated. The results were analyzed using a two-way or one-way analysis of variance and the Tukey test (α = 0.05). At the apex level, Group 3N exhibited the least canal deviation among the three groups (p < 0.05). The downward force was Group 3N > Group 2N > Group 1N (p < 0.05). The upward force, representing the screw-in force, was Group 3N > Group 1N (p < 0.05). The total instrumentation time was Group 1N > Group 3N (p < 0.05). In conclusion, increasing the downward load during PTN rotary instrumentation improved the canal centering ability, reduced the instrumentation time, and increased the upward force.

The dentine-sealer interface: modulation of antimicrobial effects by irrigation

AIM

Assess whether sodium hypochlorite (NaOCl) or chlorhexidine (CHX) and two irrigation protocols may alter the antibacterial properties of dentine and three endodontic sealers using a novel ex vivo tooth model.

METHODOLOGY

Prior to antibacterial testing, the tooth model was validated by means of scanning electron microscopy (SEM) to evaluate the separation between dentine and sealer surfaces. Root blocks prepared from extracted human roots were pretreated with 17% EDTA + 0.9% saline and subsequently treated with 1% NaOCl (G1), 2% CHX (G2) or no irrigant (G3). Two irrigation protocols were further investigated, "1% NaOCl + 17% EDTA" (P1) and "1% NaOCl + 17% EDTA + 2% CHX" (P2). Following irrigation, the root blocks were either filled with AH Plus, BioRoot RCS and Pulp Canal Sealer (PCS), or left empty. All groups were incubated for 1, 7 and 28 days. Direct contact tests for planktonic E. faecalis and 48 hours E. faecalis biofilms were performed at the level of dentine and sealer surfaces. Statistical analysis was performed on the bacterial survival between irrigants (G1, G2 and G3) and between irrigation protocols (P1 and P2) (p<0.05).

RESULTS

The model was considered reproducible as SEM examination of dentine samples indicated consistent separation between dentine and sealer surfaces. Irrigation with CHX (G2) and irrigation protocol (P2) enhanced the antibacterial properties of dentine without sealer application as well as dentine in contact with all three sealers tested, especially against planktonic E. faecalis. G2 and P2 also improved the antibacterial effect of AH Plus surfaces for all three incubation times. No irrigation groups (G1, G2) or irrigation protocols (P1, P2) altered the antibacterial properties of BioRoot RCS surfaces against planktonic bacteria or biofilms. Only BioRoot RCS surfaces eliminated the planktonic E. faecalis in all irrigation groups (G1, G2, G3) and protocols (P1, P2) investigated while PCS surfaces eliminated E. faecalis in biofilms in all groups up to 7 days.

CONCLUSIONS

The tooth model was reproducible. CHX improved the antibacterial activity upon both sealer and dentine surfaces. Among sealers, BioRoot RCS was less affected by NaOCl and CHX, and exhibited high antibacterial properties regardless the irrigation applied.

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

Simple Summary

The 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.

Abstract

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.

An Update on Nickel-Titanium Rotary Instruments in Endodontics: Mechanical Characteristics, Testing and Future Perspective-An Overview

Since the introduction of Nickel-Titanium alloy as the material of choice for the manufacturing of endodontic rotary instruments, the success rate of the root canal therapies has been significantly increased. This success mainly arises from the properties of the Nickel-Titanium alloy: the biocompatibility, the superelasticity and the shape memory effect. Those characteristics have led to a reduction in time of endodontic treatments, a simplification of instrumentation procedures and an increase of predictability and effectiveness of endodontic treatments. Nevertheless, the intracanal separation of Nickel-Titanium rotary instruments is still a major concern of endodontists, with a consequent possible reduction in the outcome rate. As thoroughly demonstrated, the two main causes of intracanal separation of endodontic instruments are the cyclic fatigue and the torsional loads. As results, in order to reduce the percentage of intracanal separation research and manufacturers have been focused on the parameters that directly or indirectly influence mechanical properties of endodontic rotary instruments. This review describes the current state of the art regarding the Nickel-Titanium alloy in endodontics, the mechanical behavior of endodontic rotary instruments and the relative stresses acting on them during intracanal instrumentation, highlighting the limitation of the current literature.

Scope of Preparation of Oval and Long-Oval Root Canals: A Review of the Literature

Successful endodontic treatment depends on cleaning and disinfecting the root canals, in order to provide conditions for three-dimensional filling, which should prevent root canal reinfection. However, anatomical complexities pose a challenge during endodontic treatment. The present study was a literature review carried out in the following databases: PubMed, SciELO, and MEDLINE, which were searched for articles published from 2017 to 2021. Micro-CT studies published in English, which analysed the capacity for preparation of oval and long-oval root canals, were included. The following keywords were used: “oval-shaped canals,” “long-oval-shaped canals,” “endodontics,” and “micro-CT.” The aim of this study was to carry out a literature review of micro-CT studies on the scope of the capacity for preparation performed in oval and long-oval root canals with rotary and reciprocating instruments.

Postoperative Pain after Use of the WaveOne Gold and XP-endo Shaper Systems: A Randomized Clinical Trial

INTRODUCTION

The present study aimed to clinically compare the incidence of postoperative pain after endodontic treatment of posterior teeth using the WaveOne Gold (WOG; Dentsply Sirona, Ballaigues, Switzerland) and XP-endo Shaper (XPES; FKG Dentaire, La Chaux-de-Fonds, Switzerland) systems.

METHODS

In a single-blind randomized clinical trial, 148 vital teeth with an indication for conventional endodontic therapy for prosthetic purposes were treated by 5 specialists following a preestablished protocol. All participants were unaware of the treatment they received. The teeth were randomly divided into 2 groups (n = 74) according to the instrumentation system used (the WOG group and XPES group). The treatments were performed in a single session. The participants were asked to rate the intensity of postoperative pain on a visual analog scale (no pain, mild pain, moderate pain, and severe pain) after 24, 48, and 72 hours and 7 days.

RESULTS

The incidence of postoperative pain was higher in the XPES group after 24, 48, and 72 hours compared with those in the WOG group (P < .05). Two participants in the WOG group experienced severe postoperative pain after 24 hours. None of the participants in either group reported pain after 7 days (P > .05, Mann-Whitney test).

CONCLUSIONS

Postoperative pain is expected after preparation of the root canal system with the WOG and XPES systems tested, but it only persists for a short period. Although more common after the use of the XPES system, the pain was classified as mild at all time points.

Shaping efficiency of XP-endo shaper and Mtwo instruments in long oval root canals: A micro-CT study

This study evaluated the shaping ability of XP-endo Shaper and Mtwo systems in long-oval-shaped canals of extracted human mandibular molars using micro-computed tomography (micro-CT). Images recorded before and after preparation were evaluated for morphometric measures regarding increase in canal volume, dentin removed, surface area, untouched walls and structure model index (SMI). Data were statistically analysed using the Mann-Whitney test with 5% of significance. On both groups, the root canal preparation significantly increased all analysed parameters (P > 0.05). There was no statistical difference between XP-endo Shaper and Mtwo systems in the increase of the canal volume (30.50%-27.82%), in volume of dentin removed (2.77%-2.40%), in the increase of the canal surface area (11.30%-8.86%), in canal untouched surfaces (9.57%-8.51%) and in the SMI (2.59%-2.68%), respectively. XP-endo Shaper and Mtwo systems showed similar shaping efficiency and were not able to completely prepare the walls of long-oval-shaped canals of extracted human mandibular molars.

Effect of XP-endo Shaper versus conventional rotary files on postoperative pain and bacterial reduction in oval canals with necrotic pulps: a randomized clinical study

AIM

To assess postoperative pain and bacterial reduction following the use of XP-endo Shaper versus conventional rotary files in preparation of oval canals with necrotic pulps.

METHODOLOGY

This superiority, parallel, randomized, double blinded clinical trial was conducted in the clinic of the Endodontic Department, Faculty of Dentistry, Cairo University, Egypt. Sixty single-canalled mandibular premolars with necrotic pulps were randomly assigned into two equal groups. Canals were instrumented using XP-endo Shaper files in the intervention group and iRaCe rotary files in the control group. Bacterial samples were taken before and after canal instrumentation. Incidence and severity of postoperative pain was assessed using a modified VAS after 6, 12, 24 h and daily for 5 days. A culture method was used to assess the number of bacterial colony forming units. Incidence of analgesic intake as well as flare-ups was recorded. Data were analysed using chi-square, Fisher Exact, Mann-Whitney, Independent t-test, and Spearman's correlation for pain and bacterial counts.

RESULTS

The XP-endo Shaper compared with the iRaCe group was associated with a significantly lower incidence of postoperative pain at 6, 12, and 24 h (P = 0.039, 0.047, and 0.026, respectively), and severity of postoperative pain at 6 h (mean difference: 1.33, 95% CI: 0.307-2.352, P = 0.02), 12 h (mean difference: 1.1, 95% CI: 0.26-1.936, P = 0.007), 24 h (mean difference: 0.94, 95% CI: 0.178-1.701, P = 0.008) and 48 h (mean difference: 0.97, 95% CI: 0.192-1.747, P = 0.038). There was a significant decrease in bacterial count following canal instrumentation in both groups (P < 0.001) with no significant difference between them (mean difference: 0.83 × 10⁵ , 95% CI: 0.336 × 10⁵ -1.996 × 10⁵ , P = 0.56). A weak correlation existed between postoperative pain severity and bacterial counts (P = 0.54). There was no significant difference in analgesic intake between the two groups (P = 0.085). Flare-ups occurred in 3.3% of teeth in the iRaCe group, while no flare-ups occurred in the XP-endo Shaper group.

CONCLUSIONS

XP-endo Shaper was associated with a significantly lower frequency of postoperative pain for up to 24 h, and lower severity of postoperative pain for up to 48 h compared with iRaCe files. Both systems were equally effective in bacterial reduction from oval root canals with necrotic pulps.

Effect of canal preparation with XP-endo Shaper and ProTaper Next on root canal geometry and dentin thickness of mandibular premolars with radicular grooves and two canals: a micro-CT study

OBJECTIVES

This study aimed to evaluate the effects of different shaping protocols on the root canal geometry and remaining dentin thickness of mandibular premolars with radicular grooves (RG) and two canals by means of micro-CT.

MATERIALS AND METHODS

Mandibular premolars with RG and two canals were matched based on their similar morphological dimensions and assigned to 2 experimental groups according to the canal preparation (n=8): XP-endo Shaper (XPS) and ProTaper Next (PTN) systems. Before and after preparation, morphometric measurements of the volume, surface area, structure model index, area, perimeter, roundness, major and minor diameters, as well as untouched canal walls, canal transportation, and dentin wall thickness were evaluated. Data were statistically compared within and between groups using the independent sample t test (α=5%).

RESULTS

XPS revealed less changes in volume, surface area, area, perimeter, and major and minor diameters (P<0.05). There was no significant difference in structure model index (SMI), roundness, and percentage of untouched canal walls between groups (P>0.05). XPS resulted in less apical canal transportation and a higher remaining dentin thickness toward the RG compared to PTN in lingual canals (P<0.05).

CONCLUSIONS

XPS revealed fewer changes in root canal geometry as well as lower transportation and a greater remaining dentin thickness in the lingual canals toward the RG compared to PTN.

CLINICAL RELEVANCE

Internal and external anatomical characteristics of mandibular premolars might have an influence on biomechanical preparation. Considering the risk of perforation, the canal preparation using XPS appears to be more conservative compared to PTN.

Analysis of the Morpho-Geometrical Changes of the Root Canal System Produced by TF Adaptive vs. BioRace: A Micro-Computed Tomography Study

We aimed to analyze the morpho-geometric changes of the root canal system created by two rotary systems (TF Adaptive and BioRace) using micro-CT technology. Two concepts of rotary file system kinematics, continuous rotation and adaptive kinematics, were used in root canal preparation. Twenty mandibular molars (n = 20) were selected with the following criteria: the teeth have mesial roots with a single and continuous isthmus connecting the mesiobuccal and mesiolingual canals (Vertucci’s Type I configuration) and distal roots with independent canals. Teeth were scanned at a resolution of 14 μm. Canals were divided equally into two groups and then enlarged sequentially using the BioRace system and TF Adaptive system according to manufacturer protocol. Co-registered images, before and after preparation, were evaluated for morphometric measurements of canal surface area, volume, structure model index, thickness, straightening, and un-instrumented surface area. Before and after preparation, data were statistically analyzed using a paired sample t-test. After preparation, data were analyzed using an unpaired sample test. The preparation by both systems significantly changed canal surface area, volume, structure model index, and thickness in both systems. There were no significant differences between instrument types with respect to these parameters (p > 0.05). TF Adaptive was associated with less straightening (8% compared with 17% for BioRace in the mesial canal, p > 0.05). Both instrumentation systems produced canal preparations with adequate geometrical changes. BioRace straightened the mesial canals more than TF Adaptive.

Micro-computed Evaluation of Canal Transportation and Centering Ability of 5 Rotary and Reciprocating Systems with Different Metallurgical Properties and Surface Treatments in Curved Root Canals

INTRODUCTION

The aim of this study was to evaluate the transportation and centering ability of 5 different rotary and reciprocating file systems with different metallurgical properties and surface treatments in curved root canals.

METHODS

Fifty mesiobuccal round canals of upper molars with a curvature of 25°-40° were assigned to 5 experimental groups (n = 12) according to the instrumentation system used: ProTaper Next (Dentsply Sirona, York, PA), Reciproc Blue (RCB [VDW, Munich, Germany]), Reciproc (VDW), TruNatomy (TRN [Dentsply Sirona]), and XP-endo Shaper (FKG, La Chaux-de-Fonds, Switzerland). During instrumentation, 5 mL 2.5% sodium hypochlorite was used in each root canal. The final irrigation protocol included 15% EDTA followed by sodium hypochlorite irrigation. The micro-computed tomographic scanning of the samples was performed before and after instrumentation to analyze the transportation and centering ability at 3 canal levels. The results were analyzed with the 1-way analysis of variance test with the corresponding post hoc test.

RESULTS

Overall, RCB caused significantly more canal transportation compared with the other techniques (P < .05). There were no significant differences between the other techniques (P > .05). ProTaper Next had a significantly better ability to stay within the central axis of the root canal compared with the Reciproc and RCB techniques (P = .046 and P = .017, respectively). In the apical third, all techniques caused similar apical transportation and centering ability (P > .05). In the middle and cervical parts of the canal, the RCB caused significantly greater canal transportation than the other techniques (P < .05).

CONCLUSIONS

Under the limitations of this study, all tested techniques had similar transportation and centering abilities in the apical part of the canal. However, the overall results and those in the middle and coronal parts of the canal indicated that reciprocating instruments resulted in more canal transportation and less centered preparations.

In vitro comparative evaluation of efficiency of XP-endo shaper, XP-endo finisher, and XP-endo finisher-R files in terms of residual root filling material, preservation of root dentin, and time during retreatment procedures in oval canals - A cone-beam computed tomography analysis

Background:

In an oval-shaped canal, no single instrumentation systems were effective in absolute removing obturation.

Aim:

The aim of the study was to evaluate the performance of ProTaper Universal Retreatment (PTUR) system, XP-endo Shaper (XPS), XP-endo Finisher (XPF), and XP-endo Finisher-R (XPF-R) in removing root-canal filling material and preservation of sound dentin during retreatment procedure.

Methodology:

Root-canal preparation was performed on 60 mandibular premolars with oval-shaped canals using the ProTaper Gold file system. Preobturation scans were performed to measure canal volume of the canal and recorded. Obturation was performed and the samples were randomly assigned into four groups according to the retreatment protocol used (n = 15): H-file, PTUR files, PTUR followed by XPF file, and XPS supplemented with XPF-R file. After retreatment, the specimens were re-scanned and volumetric analysis of remaining root filling material, volume of the canal space were measured using EZ-3Di Software Version 5.0.0.2. All the data were subjected to one-way ANOVA and post hoc Tukey's test with a significance of 5%.

Results:

XPS + XPF-R showed promising results in the removal of obturating material and preservation of root dentin than any other group. The difference is statistically significant.

Conclusion:

XPS + XPF-R removed gutta-percha more significantly without sacrificing the sound dentin along with instrumentation.