Effectiveness of continuous chelation irrigation protocol in endodontics: a scoping review of laboratory studies

This scoping review aimed to synthesize and explore the current boundaries and limitations of laboratory research on the effectiveness of continuous chelation irrigation protocol in endodontics. This scoping review was reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Extension for Scoping Reviews. Literature search was conducted on Pubmed and Scopus to identify all laboratory studies evaluating smear layer and hard-tissue debris removal or, antimicrobial efficacy, or dentine erosion induced by continuous chelation. Two independent reviewers performed the all review steps and the relevant items were recorded. Seventy-seven potentially relevant studies were identified. Finally, 23 laboratory studies met the eligibility criteria for qualitative synthesis. Seven studies focused on the smear layer/debris removal outcome, 10 on antimicrobial activity, and 10 on dentine erosion. In general, the continuous chelation protocol was equally or more effective in the cleanliness of root canals and antimicrobial activity compared with traditional sequential protocol. In addition, etidronate solutions seemed to be milder chelating agents compared to those with EDTA, thus resulting in reduced or no dentine erosion and roughness modification. Yet, the methodological differences among the included studies limit the results' generalizability. The continuous chelation seems to be equally or more effective in all investigated outcomes when compared with the traditional sequential protocol. The methodological variability among the studies and shortcomings in the methods employed limit the generalizability and clinical relevance of the results. Standardized laboratory conditions combined with reliable three-dimensional investigation approaches are necessary to obtain clinically informative findings.

Cone-Beam Computed Tomography Assessment of Prevalence of Procedural Errors in Maxillary Posterior Teeth

A range of procedural errors can occur when performing endodontic treatment on posterior teeth. These errors may decrease the success rate in endodontic practice. This study assessed the prevalence of procedural errors and the quality of endodontic treatments in maxillary molars and premolars using cone-beam computed tomography (CBCT). CBCT scans from two private radiology centers were assessed retrospectively to ensure the same calculated sample size of 327 teeth for each of the four maxillary posterior tooth types (a total of 1,308 endodontically treated teeth). Image sets were evaluated for procedural errors categorized as follows: obturation length (overfilling or underfilling by >2 mm short of the root apex), missed canals, perforations, strip perforations (with extrusion of material into the furcation area), separated instruments in the root canal space, and root fracture. Data were analyzed with SPSS version 20 (SPSS Inc., Chicago, IL, USA), and frequency data was assessed using the Monte Carlo test at the 0.05 level of significance. The procedural errors most commonly reported in the present study were from most frequent to least frequent: underfilled canals (50.0%), missed canals (27.5%), overfilled canals (12.5%), apical perforations (5.0%), separated instruments (3.1%), and root fractures (1.9%). No strip perforations (with extrusion of material into the furcation area) were seen in the study (0%). Underfilled and missed root canals were the most frequent procedural errors identified in the present study. These findings underline the importance of more consideration of critical working length management during all stages of root canal treatment, greater awareness of root canal anatomy, and the use of imaging and diagnostic devices that enhance the ability to identify and treat root canals both safely and effectively.

Effectiveness of intentional replantation in managing teeth with apical periodontitis: A systematic review

BACKGROUND

Intentional replantation (IR) to treat disease of endodontic origin remains controversial. While IR has been advocated by some clinicians as another valid treatment option, others consider it as a treatment procedure of last resort.

OBJECTIVE

To systematically review and critically evaluate the effectiveness of IR compared with nonsurgical root canal treatment/retreatment or apical surgery in terms of clinical and patient-related outcomes in managing permanent teeth with apical periodontitis (AP).

METHODS

A literature search of five databases (PubMed, Embase, Scopus, Web of Science and Cochrane Central register of Controlled Trials), and the grey literature (Networked Digital Library of Theses and Dissertations, Open Access Theses and Dissertations, DART-Europe E-theses Portal, British Library E-Theses Online Service), from inception to November 2021, was conducted. Randomised clinical trials, comparative clinical trials (CCTs), nonrandomised, retrospective, and prospective comparative cohort and case-control two arm studies which evaluated clinical and/or patient-related outcomes of permanent teeth with AP treated with IR compared with nonsurgical root canal treatment/retreatment or apical surgery were identified. The quality of the studies was appraised using the Cochrane risk of bias tool for randomized trials (RoB 2.0), the Robins-I for nonrandomized controlled clinical trials and the Newcastle-Ottawa scale for observational studies. Two independent reviewers were involved in the literature selection, performed the data extraction and the appraisal of the studies identified; disagreements were resolved in conjunction with a third reviewer.

RESULTS

No comparative study was identified from the literature search. Four longitudinal studies (one prospective and three retrospective) were identified during the screening of titles and abstracts but were excluded after reading the full text, because only IR was evaluated (single arm studies).

DISCUSSION

The available evidence on IR is mainly based on observational studies, which reported high overall mid- to long-term survival, and low complication rates. The results suggest that IR may represent an alternative treatment procedure to solve problems of endodontic origin. However, in the absence of high-quality evidence from CCTs, clinical decision-making should be on a case-by-case basis and in accordance with the clinician's experience and the patient's preference.

CONCLUSION

Clinical studies showed that IR may be a treatment modality to manage problems of endodontic origin. However, clinical trials comparing the effectiveness of IR with nonsurgical root canal treatment/retreatment or apical surgery are still required given the paucity of evidence.

Efficacy of different irrigant activation devices in removing dentin debris from an artificial isthmus connecting curved canals

The aim of this study was to evaluate the debridement efficacy of sonic irrigation (EDDY; VDW, Munich, Germany and EndoActivator; Dentsply-Sirona, Ballaigues, Switzerland) and ultrasonically activated irrigation (Irrısafe; Satelec Acteon, Merignac, France) in a simulated canal isthmus connecting curved canals. Transparent resin blocks were produced containing two curved canals connected with an isthmus. The isthmus was then filled with dentin debris. Three irrigant activation cycles were performed and the amount of remaining debris was compared analysing pictures taken after each activation cycle. Data were statistically analysed using one-way ANOVA and post hoc Tukey tests at a significance level of p < 0.05. EDDY showed greater efficiency in removing dentin debris from the simulated isthmus than the other techniques tested. An increase in the activation time enhanced the efficiency of both EDDY and ultrasonically activated irrigation in debris removal.

A review of the latest developments in rotary NiTi technology and root canal preparation

The introduction of nickel-titanium (NiTi) mechanical instruments dramatically changed clinical endodontics over the last few decades. Before NiTi, it was necessary to use more instruments to create an ideal root canal shape, and many approaches, sequences and techniques were developed over the years. Recently, NiTi endodontic instruments have undergone a series of changes brought about by modifications in design, surface treatments, and thermal treatments to improve their root canal preparation outcomes and reduce associated canal preparation risks during root canal treatment. Heat treatment is one of the most fundamental approaches to improving the fatigue resistance and flexibility of NiTi endodontic instruments. In addition, new kinematics have been developed to offer greater safety and efficiency. This narrative review describes the general properties and manufacturing of NiTi instruments, and the mechanical system evolution of NiTi instruments.

Evaluation of Dentine Structure Loss after Separated File Retrieval by Three Different Techniques: An Ex-vivo Study

OBJECTIVE

To evaluate the success rate of retrieving separated instrument, the root canal volume changes using cone-beam computed tomography and the retrieval time using Ruddle's technique, Terauchi file retrieval kit (TFRK) and Endo Rescue kit.

METHODS

Sixty human mandibular first molars were selected, and a 4-mm portion of #25/.04 rotary files were separated in the middle third of moderately curved mesio-buccal canals. Teeth were randomly assigned into three groups (n=20): R group, in which separated files were retrieved according to Ruddle's technique; T group, in which separated files were retrieved using TFRK and E group, in which separated files were retrieved using Endo Rescue kit. Values were analyzed using IBM SPSS. Results presented as mean+-standard deviation and 95% confidence interval for the root canal volume and time and frequency (%) for success rate. Comparisons of differences in time, canal volume and success rate between groups were assessed.

RESULTS

Retrieval was successful in R and T groups (70% and 80% respectively) without any significant difference between them (p=0.715), while E group hadn't any successful samples (0.0%) with significant difference compared to R and T groups (p<0.001, p<0.001). E group showed the highest increase in canal volume followed by R group, while T group exhibited the lowest increase in canal volume. There was no significant difference in the mean retrieval time between R and T groups (p=0.815).

CONCLUSION

TFRK provides a more conservative way for retrieval of separated instrument from the middle third of moderately curved canals. (EEJ-2023-01-01).

Stronger than Ever: Multifilament Fiberglass Posts Boost Maxillary Premolar Fracture Resistance

This paper investigates the influence of cavity configuration and post-endodontic restoration on the fracture resistance, failure mode and stress distribution of premolars by using a method of fracture failure test and finite elements analysis (FEA) coupled to Weibull analysis (WA). One hundred premolars were divided into one control group (G_contr) (n = 10) and three experimental groups, according to the post-endodontic restoration (n = 30), G₁, restored using composite, G₂, restored using single fiber post and G₃, restored using multifilament fiberglass posts (m-FGP) without post-space preparation. Each experimental group was divided into three subgroups according to the type of coronal cavity configuration (n = 10): G_1O, G_2O, and G_3O with occlusal (O) cavity configuration; G_1MO, G_2MO, and G_3MO with mesio-occlusal (MO); and G_1MOD, G_2MOD, and G_3MOD with mesio-occluso-distal (MOD). After thermomechanical aging, all the specimens were tested under compression load, and failure mode was determined. FEA and WA supplemented destructive tests. Data were statistically analyzed. Irrespective of residual tooth substance, G₁ and G₂ exhibited lower fracture resistance than G_contr (p < 0.05), whereas G₃ showed no difference compared to G_contr (p > 0.05). Regarding the type of restoration, no difference was highlighted between G_1O and G_2O, G_1MO and G_2MO, or G_1MOD and G_2MOD (p > 0.05), whereas G_3O, G_3MO, and G_3MOD exhibit higher fracture resistance (p < 0.05) than G_1O and G_2O, G_1MO and G_2MO, and G_1MOD and G_2MOD, respectively. Regarding cavity configuration: in G₁ and G_2, G_1O and G_2O exhibited higher fracture resistance than G_1MOD and G_2MOD, respectively (p < 0.05). In G₃, there was no difference among G_3O, G_3MO and G_3MOD (p > 0.05). No difference was found among the different groups and subgroups regarding the failure mode. After aging, premolars restored with multifilament fiberglass posts demonstrated fracture resistance values comparable to those of an intact tooth, irrespective of the different type of cavity configuration.

Micro-shear bond strength of different calcium silicate materials to bulk-fill composite

Introduction

This study aimed to compare the micro-shear bond strength (µSBS) performances of two resin-based calcium silicate-based cement (CSC) (TheraCal PT and TheraCal LC), Biodentine, and two modified-MTA CSC materials (NeoMTA 2 and BioMTA+) to bulk-fill restorative material.

Materials and Methods

Fifty 3D printed cylindrical resin blocks with a central hole were used (2 mm in depth and 4 mm in diameter). CSCs were placed in the holes (per each group n = 10) and incubated for 24 h. Cylindrical polyethylene molds (2 mm in height and diameter) were used to place the bulk-fill restorative materials on the CSCs and polymerize for 20 s. Then, all specimens were incubated for 24 h at 37 °C at a humidity of 100%. Specimen’s µSBSs were determined with a universal testing machine. Data were analyzed with one-way ANOVA (Welch) and Tamhane test.

Results

Statistically higher µSBS was found for TheraCal PT (29.91 ± 6.13 MPa) (p < 0.05) respect to all the other materials tested. TheraCal LC (20.23 ± 6.32 MPa) (p > 0.05) reported higher µSBS than NeoMTA 2 (11.49 ± 5.78 MPa) and BioMTA+ (6.45 ± 1.89 MPa) (p < 0.05). There was no statistical difference among TheraCal LC, NeoMTA 2 and Biodentine (15.23 ± 7.37 MPa) and between NeoMTA 2 and BioMTA+ (p > 0.05).

Conclusion

Choosing TheraCal PT as the pulp capping material may increase the adhesion and µSBS to the bulk-fill composite superstructure and sealing ability.

Comparison of shaping ability of the Reciproc Blue and One Curve with or without glide path in simulated S-shaped root canals

Objectives

This study aimed to assess the impact of a glide-path on the shaping ability of 2 single-file instruments and to compare the centering ability, maintenance of original canal curvatures and area of instrumentation in simulated S-shaped root canals.

Materials and Methods

Forty simulated S-shaped root canals were used and were prepared with One Curve (group OC), One G and OC (group GOC), Reciproc Blue (group RB) and R-Pilot and RB (group PRB) and scanned before and after instrumentation. The images were analyzed using AutoCAD. After superimposing the samples, 4 levels (D1, D2, D3, and D4) and 2 angles (Δ1 and Δ2) were established to evaluate the centering ability and modification of the canal curvatures. Then, the area of instrumentation (ΔA) was measured. The data were analyzed using 2-way analysis of variance and Tukey's test for multiple comparisons (p < 0.05).

Results

Regarding the centering ability in the apical part (D3, D4), the use of the glide-path yielded better results than the single-file groups. Among the groups at D4, OC showed the worst results (p < 0.05). The OC system removed less material (ΔA) than the RB system, and for Δ1, OC yielded a worse result than RB (p < 0.05).

Conclusions

The glide-path improved the centering ability in the apical part of the simulated S-shaped canals. The RB system showed a better centering ability in the apical part and major respect of the canal curvatures compared with OC system.

The micro‐shear bond strength of new endodontic tricalcium silicate‐based putty: An in vitro study

This study aimed to compare in vitro micro-shear bond strength (μSBS) of three different endodontic tricalcium silicate-based materials in contact with a bulk-fill resin-based composite. Thirty cylindrical resin blocks with a hole in the centre (2 mm in depth and 4 mm in diameter) were manufactured with a 3D printer and divided into three groups (n = 10), depending on the calcium silicate cement used: light curing TheraCal LC (Bisco, Schaumburg, IL, USA), liquid-powder NeoMTA 2 (NuSmile Avalon Biomed, Bradenton, FL, USA) and putty NeoPutty (NuSmile, Houston, TX, USA). Each sample was stored for 24 h at 37°C and 100% humidity. Then, after adhesive placement, the restorative material Filtek bulk-fill (3 M ESPE, St. Paul, MN, USA) was placed over the capping material using cylindrical plastic capsules (2 mm height and 2 mm) and polymerised for 20 s. Specimens were then tested in a universal testing machine for the compression load resulting in the μSBS. The data were compared with the one-way ANOVA (Welch) and the Tamhane test. The mean value was significantly higher in the TheraCal LC group than in the other two groups (p < 0.05). There was no significant difference between NeoMTA 2 and NeoPutty groups (p > 0.05). The majority of failure modes for all groups were cohesive within biomaterial. Using TheraCal LC in the pulp capping procedure can result in higher bond strength values to the tested bulk-fill resin-based composite than NeoMTA 2 and NeoPutty.

Instrumentation Kinematics Does Not Affect Bacterial Reduction, Post-Operative Pain and flare-ups: A Randomized Clinical Trial

AIM

This randomized clinical trial aimed to assess the effect of instrumentation kinematics (reciprocation or continuous rotation) on bacterial reduction, post-operative pain and incidence of flare-ups after root canal treatment of single-rooted mandibular premolars with asymptomatic apical periodontitis.

METHODOLOGY

Sixty-six patients were included in this prospective, parallel, randomized clinical trial. Patients were randomly allocated into two groups (N=33) according to the kinematics of the shaping instrument: WaveOne Gold (WO) used in reciprocation or One Shape (OS) used in continuous rotation. Under complete asepsis, bacterial samples were taken before (S1) and after (S2) a standard cleaning and shaping protocol. Evaluation of bacterial reduction was done by both culture technique and quantitative real-time polymerase chain reaction (qPCR) analysis. Post-operative pain was evaluated using the visual analog scale (VAS) after 24, 48- and 72-hours following treatment, while flare-ups were recorded as a binary outcome (Yes/No). Independent and paired t-tests were used for inter and intragroup comparisons for bacterial count data respectively. For post-operative pain score, intergroup comparisons were analyzed using Mann-Whitney U test while intragroup comparisons were analyzed using Friedman test followed by pairwise comparisons utilizing Wilcoxon signed rank test with Bonferroni correction. The significance level was set at p≤0.05 within all tests.

RESULTS

All the allocated participants received the intervention and were analyzed. The comparison between culture and qPCR methods showed that qPCR analysis demonstrated significantly higher pre-instrumentation baseline bacterial count (p<0.05). The percentage of bacterial reduction, detected by either method, significantly decreased after instrumentation using either rotation or reciprocation kinematics (p<0.05). However, the difference between the WOG or OS files was statistically non-significant (p>0.05). The intra-group comparisons showed a significant reduction in post-operative pain with time (p<0.05) for both groups. However, the inter-group comparison demonstrated that the difference in post-operative pain after the use of either WOG or OS was statistically non-significant (p>0.05). The incidence of flare-ups between both groups was also not-significant (p=1).

CONCLUSIONS

Shaping kinematics, either rotation or reciprocation motions, had no impact on bacterial reduction and the incidence of post-operative pain and flare-ups after root canal preparation of single-rooted premolars with asymptomatic apical periodontitis.

Effectiveness of XP-Endo Finisher and Passive Ultrasonic Irrigation in the Removal of the Smear Layer Using two Different Chelating Agents

STATEMENT OF THE PROBLEM

The smear layer may harbor microorganisms and necrotic pulp tissue, jeopardizing irrigant penetration. Recently, Dual Rinse®, a weak chelating agent, has been introduced to the market. However, its chelating capacity in the final irrigation protocol with different activation systems has not yet been deeply analyzed.

PURPOSE

The aim of this ex vivo study was to evaluate the effectiveness of passive ultrasonic irrigation (PUI) and XP-endo Finisher (XP) on smear layer removal in combination with two chelating agents, ethylenediaminetetraacetic acid (EDTA) and etidronic acid (HEDP).

MATERIALS AND METHOD

This in vitro, experimental study evaluated fifty-two single-rooted human teeth were standardized to 16 mm in length. Root canal instrumentation was performed by the ProTaper Gold system up to the F4 file. The apical end of the samples was sealed with wax to simulate a closed system. Teeth from group 1 (n=24) were irrigated with 3% sodium hypochlorite (NaOCl) and 17% EDTA, while teeth from group 2 (n=24) were irrigated with 3% NaOCl mixed 9% HEDP. Both groups were divided into two subgroups (n=12) depending on the activation system used: XP (group XP-EDTA and XP-HEDP) or PUI (group PUI-EDTA and PUI-HEDP). The specimens were evaluated by scanning electron microscopy at 3, 5 and 8mm from the apex. Statistical analysis was performed using ANOVA and Bonferroni tests considering p> 0.05 as significant.

RESULTS

PUI-EDTA was the most effective at removing the smear layer, with a statistically significant difference from XP-EDTA (p< 0.042) and group XP-HEDP (p< 0.003). There were no statistically significant differences among the other groups.

CONCLUSION

Under the conditions of this ex vivo study, no activation system was able to completely remove the smear layer from the root canal walls. However, the combination of NaOCl with ultrasonically activated EDTA obtained better results than the other treatments.

Effect of a novel laser-initiated photoacoustic activation of a solvent or sodium hypochlorite in the removal of filling remnants after retreatment of curved root canals

BACKGROUND

This study aimed to evaluate the effect of Er:YAG laser-initiated shockwave-enhanced emission of photoacoustic streaming (SWEEPS®) and passive ultrasonic irrigation (PUI) combining thymol-based solvent or sodium hypochlorite (NaOCl) in the removal of filling remnants from curved canals.

METHODS

Forty-eight curved root canals were instrumented and filled with an epoxy-resin-based sealer and gutta-percha. The canals were retreated with a Wave One Gold primary file (tip size 25; variable taper) and sodium hypochlorite (NaOCl). After the retreatment, the samples were randomly divided into four groups according to the additional irrigation protocol: PUI/NaOCl, PUI/solvent, SWEEPS®/NaOCl or SWEEPS®/solvent. The volume of filling material in root canal was measured after root canal filling, after mechanical retreatment, after final irrigation protocol and after additional irrigation protocol, using micro-CT. The results were analyzed using Kruskal-Wallis test with the post-hoc Mann-Whitney U test and Wilcoxon test (α=0.05).

RESULTS

In the PUI group, irrigation with the solvent or NaOCl resulted in similar filling reduction (p = 0.224). In the SWEEPS® group, irrigation with NaOCl resulted in a significantly greater filling reduction compared to the solvent (p = 0.021). The SWEEPS®/NaOCl group was more effective than the PUI/NaOCl group (p = 0.008). No significant differences were found between PUI/solvent and SWEEPS® groups (p>0.05) and PUI/NaOCl and SWEEPS®/solvent group (p>0.05).

CONCLUSION

Although all tested protocols improved the removal of filling remnants from curved root canal, the SWEEPS® was more successful than PUI when NaOCl was used. Both tested techniques showed similar efficacy when in combination with the solvent.

Effects of ultrasonic refinement on endodontic access cavity walls: A microcomputed tomography analysis

Objectives

The present study aimed in assessing the coronal defects after access cavity finishing and refinement by micro.

Methods

Access cavities on thirty molars were prepared using a diamond bur. To finish and refine the access cavity, the Endo-Z was used in group 1 (n=15) and Start X 1 in group 2. Preparation time was recorded. A micro-CT scan was done before and after access preparation. Formation and location of the new defects were registered, the extension of defects calculated and the direction of the extension registered, preparation time and surface roughness determined (P < 0.05).

Results

Preparation time was significantly higher with ultrasonics (P <0.001). Internal walls showed smoother surfaces for Endo-Z group. Newly counts and extension length of defects weren't significantly different between groups (P > .05).

Conclusion

Ultrasonic tips induced new cracks. Both instruments caused the extension of cracks. Ultrasonic tips requires more time and results in significantly rougher surfaces.

A comparison of near-infrared imaging with other diagnostic tools for dental caries

Dental caries is one of the most common diseases in the world, and global incidence rates are increasing. The early detection of dental lesions enables a conservative approach to be employed and represents a priority in modern dentistry. Recent studies have suggested that conventional diagnostic methods, such as visual tactile inspection and X-ray examination, exhibit low sensitivity and are not very effective in early diagnoses. Consequently, late detection of decay is associated with an increased loss of tooth structure. New diagnostic systems based on optical properties have been developed to facilitate early detection. Several studies have evaluated the performance of near-infrared imaging (NIRI) as an early diagnostic tool. NIRI using light ranging from 700 to 1700 nm has demonstrated better optical properties compared to conventional optical systems using light in the visible spectra. NIRI enables deeper penetration of the light in the tooth tissue, weak scattering with lower background noise and strong photon absorption with detailed images. Several in vivo studies have demonstrated that NIRI technology has the potential to improve performance compared with current diagnostic methods. NIRI exhibits increased sensitivity compared to radiographs and is more suitable to identify approximal enamel lesions. This paper aims to review these recent advances and their potential applications in daily clinical practice.

Dental Practice after COVID-19 Pandemic: Analysis of Italian Guidelines and Current Literature to Propose Appropriate Protocols for Dental Practices

On March 11^th, 2020, WHO declared COVID-19 a pandemic. This disease is caused by SARS-CoV-2, a virus that can be spread by symptomatic or asymptomatic carriers through contact, droplets and airborne transmission. Because of the transmission routes of this virus, dental treatments are considered “high risk” procedures, both for patients and operators. Italy was one of the most affected European countries and experienced a long lockdown period. Guidelines were provided by the Italian Health Ministry for a safe reopening of dental practices. In this article those guidelines are reported and compared with the available literature. The Italian model for reopening dental practice appears to be coherent with the indications provided by WHO and is supported by several studies.

The fate of overfilling in root canal treatments with long-term follow-up: a case series

This study describes 6 cases of endodontic overfilling with successful clinical outcomes during long-term (up to 35 years) radiographic follow-up. Successful endodontic treatment depends on proper shaping, disinfection, and obturation of root canals. Filling materials should completely fill the root canal space without exceeding the anatomical apex. Overfilling may occur when the filling material extrudes into the periapical tissues beyond the apex. The present case series describes 6 root canal treatments in which overfilling of root canal sealer and gutta-percha accidentally occurred. Patients’ teeth were periodically checked with periapical radiographs in order to evaluate the outcomes during long-term follow-up. All cases showed healing and progressive resorption of the extruded materials in the periapex. The present cases showed that if a 3-dimensional seal was present at the apical level, overfilling did not negatively affect the long-term outcomes of root canal treatment.

European Society of Endodontology position statement: Surgical extrusion, intentional replantation and tooth autotransplantation: European Society of Endodontology developed by

This European Society of Endodontology (ESE) position statement on surgical extrusion, intentional replantation and tooth autotransplantation represents the consensus of an expert committee, convened by the ESE. A narrative review in the International Endodontic Journal (Plotino et al. 2020, international Endodontic Journal, 53, 1636-52) formed the basis for the position statement. The review provided detailed information on the background, clinical procedures and the outcome of surgical extrusion, intentional replantation and tooth autotransplantation techniques. The aim of the current statement is to summarize the best available evidence on these clinical techniques to provide appropriate clinical guidance to undergraduate and postgraduate students, dental practitioners, clinical teachers and researchers. The current position statement will be updated by the ESE periodically to reflect new evidence as it becomes available to provide the most current treatment guidance for clinical practice.

Clinical fracture incidence of rotary and reciprocating NiTi files: A systematic review and meta-regression

This systematic review was registered in PROSPERO (CRD42017075917) and aimed to investigate whether the available clinical evidence supports the hypothesis that reciprocating motion results in a lower incidence of nickel-titanium files fracture compared to continuous rotation. Clinical studies that reported the incidence of fracture of engine-driven nickel-titanium files were included. The main exposure was the kinematics, and the primary outcome was the incidence of files fracture. The overall incidence of files fracture was 2.27%, with a trend for higher incidence with rotary motion (2.43%) than with reciprocating (1.0%), though without significant differences. Multiple meta-regression models revealed that the use of nickel-titanium files in more than four teeth and less proficient operators were associated with a higher incidence of file fracture. There was no difference in the clinical incidence of fracture of nickel-titanium instruments between reciprocating and rotary motions; however, other factors were identified.

Influence of Rotation Speed of Mtwo Files on Root Canal Instrumentation Time with Different Canal Curvatures

Introduction

The aim of this study was to analyze the effect of rotation speed on the instrumentation time of root canals with different curvatures using Mtwo NiTi rotary instruments.

Methods and Materials

Forty root canals were selected and divided into 2 groups, according to the angle of curvature (group A>30^°, group B<30^°). Both groups were divided into 2 subgroups (n=10), according to the rotational speed used for root canal instrumentation (150 rpm: group A1 and B1; 250 rpm: group A2 and B2). The total instrumentation time and the total number of instrumentation cycles (NCI) required to complete root canal preparation were registered for each canal. The mean and standard deviation were then calculated. Data were then statistically analyzed using two-way ANOVA and interaction effect P-values (P<0.05).

Results

During root canal instrumentation, there were no file fractures. Total instrumentation time of the low speed groups A1 (150 rpm) and B1 (150 rpm) were significantly higher (P<0.05) than that of the high speed groups, A2 (250 rpm) and B2 (250 rpm); however, there was no statistically significant difference in terms of NCI between the different groups (P>0.05). Statistical difference was not found between the different angles of curvature, group A1 vs B1 and A2 vs B2 in terms of total instrumentation time (P>0.05) and NCI (P>0.05).

Conclusions

This ex-vivo study showed that canal preparation with Mtwo rotary files could be completed safely with an increase of the instrumentation time at low rotational speed independently of the root canal curvature.

Safety of large preparation with different instruments in the buccal canals of maxillary molars

This study aimed to evaluate the influence of large apical preparations with Reciproc (REC), Hyflex CM (HCM) and Twisted File Adaptive (TFA) systems using micro-computed tomography (MCT). Ninety mesiobuccal (MB) and distobuccal (DB) root canals of maxillary molars (n = 45) were scanned using MCT before and after the shaping procedures. The root canals (n = 15) were prepared until REC 40.06, HCM 40.04 and TFA 35.04. The root canal transportation (RCT), centring ability (CA), change in volume of the root canal and at different levels (VC), remaining dentine thickness (RDT), removal of dentine wall (RDW) and working time (WT) were evaluated. Data were analysed using the Kruskal-Wallis and Dunn tests, and the one-way ANOVA and Tukey tests with a level of significance set at 5%. No significant difference among the instruments was found regarding the RCT, CA, RDT, RDW and WT (P > 0.05), in larger apical preparations in curved MB and straight DB canals of maxillary molars.

The management of deep carious lesions and the exposed pulp amongst members of two European endodontic societies: a questionnaire-based study

AIMS

To investigate and compare views on management of deep caries and the exposed pulp by Endodontic Society members in Ireland (Irish Endodontic Society [IES]) and Italy (Accademia Italiana di Endodonzia [AIE]). Further aims were to investigate the influence of patient-related factors (age, symptoms) and operator-related factors (material choice, antibiotics) on management.

METHODOLOGY

A structured online questionnaire containing two cases (an 18- and 45-year-old) and two scenarios (± mild symptoms), including history and radiograph, was sent to IES and AIE members. The answers were analysed using chi-square and Fisher's exact test (P < 0.05).

RESULTS

In total, 120 dentists participated, representing 49% of the AIE and 48% of the IES membership. Age distribution was similar between the societies; however, most AIE members had no further qualifications (63%), while IES respondents generally had a postgraduate endodontic qualification (71%). AIE respondents carried out a larger volume of vital pulp treatment (VPT) per month, with 69% carrying out over five cases, compared with 22% of IES respondents. The presence of patient symptoms significantly altered treatment planning decisions (P < 0.001) with root canal treatment (RCT) more frequently selected in both societies. Patient age significantly influenced treatment choice in the absence (P = 0.043) or presence (P = 0.012) of symptoms with less VPT advocated in older patients. There were no significant differences in the treatment of a young patient in the presence (P = 0.302) or absence of symptoms (P = 0.297); however, older patient management differed between the societies for symptomatic (P = 0.041) and asymptomatic scenarios (P = 0.044) with significantly more RCTs carried out in the AIE than the IES. Hydraulic calcium silicate materials were commonly selected, accounting for 81% of IES and 69% of AIE VPT materials, although younger members of the AIE preferred calcium hydroxide materials. Younger dentists in both societies prescribed less RCT than older age groups.

CONCLUSIONS

Although VPT is carried out by members of both societies there was no consistency regarding the most appropriate management for the exposed pulp or the VPT material of choice. Patient symptoms and age significantly influence the decision-making process and invasiveness of treatment. Hydraulic calcium silicate materials were the most commonly advocated material in all groups except young AIE members who preferred calcium hydroxide.

Cyclic fatigue resistance of reduced-taper nickel-titanium (NiTi) instruments in doubled-curved (S-shaped) canals at body temperature

Background. This study was conducted to compare the cyclic fatigue resistance of VDW.ROTATE, TruNatomy Prime, HyFlex CM, and 2Shape nickel-titanium (NiTi) rotary instruments in double-curved canals in a simulated clinical environment. Methods. Eighty NiTi files were used for the fatigue testing in stainless steel canals compatible with instrument sizes until fracture occurred (n=20): VDW.ROTATE (04./25#), TruNatomy Prime (04./26#), HyFlex CM (04./25#) and 2Shape TS04./25#( 1). For each instrument, the number of cycles to fracture (NCF) was calculated, and the fractured fragment length (FL) was measured. To verify that the files were fractured due to cyclic fatigue, the fractured surfaces of the files were evaluated under a scanning electron microscope. Data were statistically analyzed using the Kruskal-Wallis and Student's t-tests at the %95 confidence level. Results. The failure of the files due to cyclic fatigue was first seen in the apical curvature before the coronal curvature (P<0.05). The highest fatigue resistance was observed in VDW.ROTATE and HyFlex CM files in both curvatures (P<0.05). There were no significant differences in the fatigue resistance between the HyFlex CM and VDW.ROTATE files or between the 2Shape and the TruNatomy files (P>0.05). There was no difference in the fractured lengths of the files between the apical and coronal curvatures (P>0.05). Conclusion. In artificial S-shaped root canals, VDW.ROTATE and HyFlex CM files exhibited higher fatigue resistance compared to 2Shape and TruNatomy files.

Comparison of the cyclic fatigue resistance of VDW.ROTATE, TruNatomy, 2Shape, and HyFlex CM nickel-titanium rotary files at body temperature

Objectives

This study aims to compare the cyclic fatigue resistance of VDW.ROTATE, TruNatomy, 2Shape, and HyFlex CM nickel-titanium (NiTi) rotary files at body temperature.

Materials and Methods

In total, 80 VDW.ROTATE (25/0.04), TruNatomy (26/0.04), 2Shape (25/0.04), and HyFlex CM (25/0.04) NiTi rotary files (n = 20 in each group) were subjected to static cyclic fatigue testing at body temperature (37°C) in stainless-steel artificial canals prepared according to the size and taper of the instruments until fracture occurred. The number of cycles to fracture (NCF) was calculated, and the lengths of the fractured fragments were measured. The data were statistically analyzed using a 1-way analysis of variance and post hoc Tamhane tests at the 5% significance level (p < 0.05).

Results

There were significant differences in the cyclic fatigue resistance among the groups (p < 0.05), with the highest to lowest NCF values of the files as follows: VDW.ROTATE, HyFlex CM, 2Shape, and TruNatomy. There was no significant difference in the lengths of the fractured fragments among the groups. The scanning electron microscope images of the files revealed typical characteristics of fracture due to cyclic fatigue.

Conclusions

The VDW.ROTATE files had the highest cyclic fatigue resistance, and the TruNatomy and 2Shape files had the lowest cyclic fatigue resistance in artificial canals at body temperature.

Influence of Negotiation, Glide Path, and Preflaring Procedures on Root Canal Shaping-Terminology, Basic Concepts, and a Systematic Review

INTRODUCTION

Negotiation, glide path, and preflaring are essential steps in root canal shaping procedures. This report aimed to discuss the terminology, basic concepts, and clinical considerations of negotiation, glide path, and preflaring procedures and the influence of these steps on root canal shaping.

METHODS

This systematic review was undertaken following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The protocol has been registered with the International Prospective Register of Systematic Reviews (number CRD42019127021). A comprehensive literature search was performed by 2 independent reviewers using a selected search strategy in 2 electronic databases (PubMed and Scopus) until January 28, 2019. A further search was performed manually in endodontic journals. Studies investigating or comparing at least 1 shaping property resulting from root canal instrumentation with a glide path or preflaring in human extracted teeth or clinical studies were included.

RESULTS

The literature shows that the definition of glide path and preflaring procedures remains controversial, which requires an elaboration in the American Association of Endodontists' Glossary of Endodontic Terms. After the removal of irrelevant and duplicated articles, 98 articles were included. The impact of glide path preparation and preflaring on working length determination, apical file size determination, canal transportation, separation of endodontic files, shaping time, dentinal microcrack formation, and extrusion of debris was discussed. Because of heterogeneity among the included studies, quantitative synthesis was not performed for most of the parameters.

CONCLUSIONS

An evidence-based guideline is needed to define and correlate the basic concepts and current applications of each step of contemporary advancements in root canal instruments. Glide path preparation reduces the risk of debris extrusion, has no influence on the incidence of dentinal crack formation, and improves the preservation of the original canal anatomy. The creation of a glide path may have no impact on Reciproc files (VDW, Munich, Germany) in reaching the full working length. Preflaring increases the accuracy of working length determination. Further randomized clinical trials are required to evaluate the effect of a glide path and preflaring on root canal treatment outcomes.

Endodontic management of an autotransplanted mandibular third molar: A simplified approach

BACKGROUND AND OVERVIEW

In this case report, the authors aim to review the standard protocols for endodontic treatment of autotransplanted molars and report on the 5-year follow-up of a clinical transplantation case.

CASE DESCRIPTION

The authors transplanted a mandibular third molar into the position of the adjacent second molar. The authors performed extraoral apicoectomy and retrograde restoration after atraumatic extraction of the donor tooth and before transplantation. The authors did not perform conventional orthograde root canal treatment after transplantation. The patient was followed up 5 years after the autotransplantation. Results of follow-up radiography showed a regular root surface without evidence of periapical lesions or root resorption.

CONCLUSIONS AND PRACTICAL IMPLICATIONS

If appropriate sterility of the working field is maintained during surgery and a tight apical seal is achieved during the extraoral treatment, orthograde endodontic treatment should be delayed or avoided.

Dual wavelength irradiation antimicrobial photodynamic therapy using indocyanine green and metformin doped with nano-curcumin as an efficient adjunctive endodontic treatment modality

BACKGROUND

Indocyanine green (ICG) doped with nano-curcumin (N-CUR) can increase photosensitivity in antimicrobial photodynamic therapy (aPDT). Since metformin (Met) provides a synergistic advantage with photosensitivity, it was conjugated with N-CUR@ICG. Aim of the study was to evaluate the photosensitizing effect of N-CUR@ICG-Met used as a new photosensitizer in dual wavelengths irradiation (diode laser and light-emitting diode, LED) aPDT in root canals infected with Enterococcus faecalis biofilm.

MATERIALS AND METHODS

Following synthesis and confirmation of N-CUR@ICG-Met by Scanning electrone microscope (SEM), Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD) and Zetasizer analysis, the mature microbial biofilm was formed. The quantitative and qualitative evaluations of E. faecalis biofilm were made using microbial viability and SEM analysis of the following groups of treatment modalities (n = 5): 1- N-CUR, 2- ICG, 3- Met, 4- N-CUR@ICG, 5- N-CUR@ICG-Met, 6- Diode laser, 7- LED, 8- aPDT/diode, 9- aPDT/LED, 10- aPDT/diode laser + LED, 11- aPDT/LED + diode laser, 12- 2.5 % sodium hypochlorite (NaOCl). In addition, E. faecalis not treated served as negative control. Data were statistically analyzed using One-way Analysis of Variance (ANOVA) and the post-Hoc Bonferroni tests with a level of significance set at P < 0.05.

RESULTS

SEM, FT-IR, XRD, Zetasizer analysis confirmed successful doping of ICG-Met onto/into N-CUR. The treatment modality of N-CUR@ICG-Met mediated aPDT/diode laser, aPDT/LED, aPDT/diode laser + LED, and aPDT/LED + diode laser statistically decreased the cell viability of E. faecalis for 69.40 %, 75.52 %, 82.74 %, and 83.84 %, respectively compared with the negative control group (P < 0.05). The double wavelengths irradiation technique, which exposed the N-CUR@ICG-Met with diode laser irradiation and immediately after with LED (i.e. group No. 10), as well as, N-CUR@ICG-Met with LED irradiation and immediately after with diode laser (i.e. group No. 11) reduced the viable E. faecalis count in biofilm structures statistically more than the other treatment modalities (P < 0.05).

CONCLUSIONS

N-CUR@ICG-Met as a new photosensitizer in dual wavelengths irradiation method may improve anti-biofilm activity of aPDT against E. faecalis.

Histologic Response of Human Pulp and Periapical Tissues to Tricalcium Silicate-based Materials: A Series of Successfully Treated Cases

Pulpal/periapical responses of human teeth that are treated successfully with tricalcium silicate-based materials are extremely difficult to obtain because of the typical unavailability of these teeth for histologic examination. The present case series reports histologic and histobacteriologic findings of 3 human teeth that had undergone pulpotomy, orthograde retreatment, and apicoectomy/root-end filling using tricalcium silicate-based endodontic materials. The teeth were extracted after 34 days, 7 weeks, and 20 months, respectively, because of unusual circumstances. The extracted teeth were processed, paraffin embedded, sectioned, stained with hematoxylin-eosin or the modified Brown and Brenn technique, and examined with light microscopy. The recurrent observation for the 3 cases presented was the absence of inflammatory or foreign body reactions of the host tissues in contact with tricalcium silicate-based materials after different observation periods despite the identification of bacteria in dentinal tubules close to the site of operation. Wound healing was rapid with repair/regeneration of lost tissues with cementum and new bone trabeculae. Although the level of evidence for a case series is low because of the anecdotal nature of the reported episodes, the histologic results reported in the present case series illustrate the highly biocompatible and bioactive nature of the tricalcium silicate-based materials used in treating these cases.

Comparison of shaping ability of ProTaper Next and 2Shape nickel—titanium files in simulated severe curved canals

Aim: To evaluate the centering ability of ProTaper Next (PTN) and 2Shape (TS) nickel—titanium (NiTi) instruments in terms of maintaining the original root canal configuration in a simulated tooth with severe curvature. Methodology: Twenty standardized simulated curved root canals were prepared to an apical size of 0.25 mm using PTN and TS (n = 10 canal/group) nickel-titanium files. A gig was constructed to enable reproducible image acquisition using a photographic camera. Pre- and post-instrumented images were recorded and superimposed using a computer software. The ability of the instruments to remain centered in the canal was determined by calculating a centering ratio at three independent points of the simulated canal: coronal, middle and apical third of the curvature, using a computer software. Statistical analysis was performed using one-way analysis of variance (ANOVA) followed by independent sample t-test at 5% significance level. Results: No significant difference was found between the two systems (p > 0.05). At the apical third, the mean centering ratio was significantly higher than the centering ratio of the coronal and the middle thirds in both TS and PTN (p < 0.05). Conclusions: There were no significant differences in the centering ability of the ProTaper Next and 2Shape systems in simulated severe curved canals. Both systems exhibited some degree of transportation, especially in the apical third.

Influence of activation mode and preheating on intracanal irrigant temperature

This ex vivo study assessed the effectiveness of two activation modes to increase the intracanal temperature of 5.25% NaOCl solution and the time for a preheated-irrigant to return to its initial temperature. Ten single-rooted extracted human teeth were used. Thermocouples were adapted to the root surface and the temperature was registered following two activation modes: ultrasound (US) and thermal. Furthermore, a preheated-solution (45°C/60°C) was flushed into root canal to test the time needed to return to its initial temperature. Data were analysed using two-way ANOVA and Tukey's post-hoc tests (P = 0.05). Statistical analysis showed differences between the activation modes. US and thermal activation increased from 37 to 40.4°C and to 62.8°C respectively in 60 s. Time for preheated-irrigant to return to its initial temperature was longer for 60°C. Preheating irrigant at 60°C and using thermal activation to keep it warm may represent a further step of the irrigation protocol.

Efficacy of sonic and ultrasonic irrigation devices in the removal of debris from canal irregularities in artificial root canals

OBJECTIVE

To evaluate the efficacy of different sonic and ultrasonic devices in the elimination of debris from canal irregularities in artificial root canals.

MATERIALS AND METHODS

A resin model of a transparent radicular canal filled with dentin debris was used. Five groups were tested, namely: Group 1 - ultrasonic insert 15.02; Group 2 - ultrasonic insert 25/25 IRRI K; Group 3 - ultrasonic insert 25/25 IRRI S; Group 4 - sonic insert 20/28 Eddy on a vibrating sonic air-scaler handpiece; Group 5 - 20.02 K-file inserted on a Safety M4 handpiece. Two different irrigants (5% sodium hypochlorite and 17% EDTA) and 3 different times of activation (20, 40, and 60 seconds) were tested. Means and standard deviations were calculated and statistically analyzed with the Kruskal-Wallis and Wilcoxon tests (p<0.05).

RESULTS

No statistically significant differences were found between the two irrigants used. Group 4 removed more debris than the other groups (p<0.05). Groups 1, 2, and 3 removed more debris than group 5 (p<0.05). A statistically significant difference (p<0.05) was found for the time of activation in all groups and at all canal levels, except between 40 and 60 seconds in group 4 at coronal and middle third level (p>0.05).

CONCLUSIONS

No significant differences were found between 5% sodium hypochlorite and 17% EDTA. When the time of activation rises, the dentin debris removal increases in all groups. Both sonic and ultrasonic activation demonstrate high capacity for dentin debris removal.

Photodynamic therapy in endodontics

Photodynamic therapy (PDT) is a treatment modality that was initiated in 1900; however, it was not until the last decade that PDT regained attention for its several favourable features during the treatment of microbial infections in endodontics. Recently, several papers advocated its use for root canal treatment. The concept of photodynamic inactivation requires microbial exposure to either exogenous or endogenous photosensitizer molecules, followed by visible light energy, typically wavelengths in the red/near-infrared region that cause the excitation of the photosensitizers resulting in the production of singlet oxygen and other reactive oxygen species that react with intracellular components and consequently produce cell inactivation and death. Recently, PDT has been suggested as a promising effective adjunct to standard antimicrobial intracanal cleaning and shaping for the treatment of periapical lesions. Current publications tested PDT in terms of bacterial load reduction in vivo, in vitro and ex vivo, showing promising results. The purpose of this article was to review the existing literature on PDT in the endodontic field regarding its mechanism of action, photosensitizers and light sources, limitations and clinical procedures. Although positive results have been demonstrated in vitro, there are considerably fewer in vivo investigations. In conclusion, more in vivo studies are needed on the use of antimicrobial PDT in root canal treatment.

Surgical extrusion: A reliable technique for saving compromised teeth. A 5-years follow-up case report

Aim: To present a long term follow up clinical case in which a compromised anterior tooth was saved by a surgical extrusion procedure. Summary: Although different techniques have been suggested for clinical crown lengthening in the anterior zone, some of them have limitations in terms of aesthetics and procedural requirements. The current case report demonstrates how a simplified surgical extrusion procedure was successfully performed for saving a severely damaged anterior tooth; furthermore, it is possible to apply the technique described in this case using minimum and simple armamentarium like a scalpel, elevators, forceps and splinting flexible cord. Key-learning points: Saving severely compromised anterior teeth is possible by applying surgical extrusion techniques when crown-root ratio allows it. Risk of root resorption or ankylosis is minimum.

Dentinal Microcrack Formation During Root Canal Treatment with Mtwo Instruments and MicroSeal Filling Technique

Objective:

The purpose of this study was to evaluate dentinal microcrack formation during root canal treatment using Mtwo NiTi rotary instruments and MicroSeal filling technique.

Materials and Methods:

Forty-five single-rooted teeth were selected for the present study and divided into 3 different groups ( n = 15): Group 1, in which root canals were instrumented with Mtwo rotary files; Group 2, in which root canals were instrumented with Mtwo rotary files and filled using the MicroSeal technique; and Group 3, that acts as a control group in which no instrumentation nor obturation were performed. Then, roots were sectioned 3 mm, 6 mm, and 9 mm from the apex and the cut surface has been observed under a stereomicroscope to check for the presence or absence of dentinal microcracks. Number of dentinal microcracks was registered for each group at different levels and data were statistically analyzed using the Chi-square test with a level of significance set at P < .05.

Results:

No statistically significant differences were registered among groups ( P < .05). No microcracks were detected in Groups 1 and 3, while two dentinal microcracks were registered in Group 2.

Conclusions:

Mtwo rotary instruments and the MicroSeal root canal filling technique did not significantly induce dentinal microcrack formation.

Impact of Minimal Root Canal Taper on the Fracture Resistance of Endodontically Treated Bicuspids

Objective:

Minimal invasive endodontics preserve coronal and radicular tooth structure to increase the fracture resistance of teeth. The aim of this study was to assess the influence of final preparation taper on the fracture resistance of maxillary premolars.

Materials and Methods:

Sixty maxillary premolars were selected and divided into 2 groups: 30 were shaped with a final apical diameter 30 and a 4% taper and 30 with 6% taper using iRaCe^® instrument (FKG dentaire, Switzerland). All root canals were irrigated with sodium hypochlorite and final rinse with ethylenediaminetetraacetic acid. All canals were filled with gutta-percha single-cone filling technique and AHPlus^® sealer (Dentsply- Maillefer, Baillagues, Switzerland) and access cavity restored with resin composite. Roots were wax coated, placed in an acrylic mold and loaded to compressive strength fracture in a mechanical material testing machine recording the maximum load at fracture and fracture pattern (favorable/restorable or unfavorable/unrestorable). Fracture loads were compared statistically, and data examined with Student t-test with a level of significance set at P ≤ 0.05.

Results:

No statistically significant difference was registered between the 4% taper of preparation (270.47 ± 90.9 N) and 6% taper of preparation (244.73 ± 120.3 N) regarding the fracture resistance of the endodontically treated premolars tested (P = 0.541), while more favorable restorable fractures were registered in the 4% taper group.

Conclusions:

Continuous 4% preparation taper did not enhance the fracture resistance of endodontically treated maxillary premolars when compared to a 6% taper root canal preparation. More fractures were registered in the 4% taper group.

The effect of root canal preparation on the surface roughness of WaveOne and WaveOne Gold files: atomic force microscopy study

Objectives

To examine the surface topography of intact WaveOne (WO; Dentsply Sirona Endodontics) and WaveOne Gold (WOG; Dentsply Sirona Endodontics) nickel-titanium rotary files and to evaluate the presence of alterations to the surface topography after root canal preparations of severely curved root canals in molar teeth.

Materials and Methods

Forty-eight severely curved canals of extracted molar teeth were divided into 2 groups (n = 24/each group). In group 1, the canals were prepared using WO and in group 2, the canals were prepared using WOG files. After the preparation of 3 root canals, instruments were subjected to atomic force microscopy analysis. Average roughness and root mean square values were chosen to investigate the surface features of endodontic files. The data was analyzed using one-way analysis of variance and post hoc Tamhane's tests at 5% significant level.

Results

The surface roughness values of WO and WOG files significantly changed after use in root canals (p < 0.05). The used WOG files exhibited higher surface roughness change when compared with the used WO files (p < 0.05).

Conclusions

Using WO and WOG Primary files in 3 root canals affected the surface topography of the files. After being used in root canals, the WOG files showed a higher level of surface porosity value than the WO files.