Effect of different retreatment files using different kinematics on the release of inflammatory mediators in root canal retreatment of single-rooted teeth: a randomized clinical trial.

OBJECTIVES: This randomized clinical trial aimed to evaluate the effect of two rotaries (ProTaper Universal Retreatment (PTUR)), D-Race (DR) + XP-Endo Finisher R (XPFR) and one reciprocating (Reciproc Blue (RB) retreatment techniques on the release of neuropeptides (Substance P, calcitonin gene-related peptide (CGRP)), and cytokines (IL-6 and IL-10) in periapical fluid in root canal retreatment of single-rooted teeth. MATERIALS AND METHODS: In this randomized clinical trial (ClinicalTrials.gov ID: NCT05039502), seventy-five patients scheduled for retreatment were randomly divided into 3 groups according to the file system used to remove root canal filling materials (n = 25): PTUR, RB, and DR + XPFR. After reshaping and disinfection of the root canals, periapical fluid samples were taken, and the levels of Substance P, CGRP, IL-6, and IL-10 were measured by enzyme-linked immunosorbent assay (ELISA) test. Data were analyzed using the Kruskal-Wallis and chi-square tests. The level of significance was set as p = 0. 05. RESULTS: All the allocated participants received the intervention and were analyzed. There was no statistically significant difference among groups in terms of gender, age, tooth localization, and the distribution of analgesic use after treatment (p values 0.799, 0.095, 0.637, 1.000, respectively). No statistically significant difference was found in terms of the levels of Substance P, CGRP, and IL-10 among groups (p > .05), except IL-6. CONCLUSIONS: PTUR, RB, and DR + XPFR files have comparable results in the expression of inflammatory mediators. CLINICAL RELEVANCE: Retreatment files powered with rotary or reciprocating motion produced similar neuropeptide and cytokine levels in patients.

Filling quality of several obturation techniques in the presence of apically separated instruments: A Micro-CT study.

Separated root canal instruments may affect the quality of root canal obturation and hence the survival of endodontically treated teeth. Obturation techniques may influence filling-quality. The aim was to evaluate the obturation quality of teeth filled with different obturation techniques in the presence of apically separated instruments using micro-computed tomography (µ-CT). Notched ProTaper F2 rotary-files were separated in the apical third of 36-human mandibular incisors with single root/canal and mature apex. Samples were filled by an endodontist according to one of the following obturation techniques (n = 12): cold lateral-compaction (CLC), single-cone (SC) and thermoplastic injection (TI). Samples were scanned by the Skyscan 1,274® µ-CT device after 1-week at 37°C in 100% humidity. Images of the sections were evaluated with CTan software in terms of total-volume and volume percentage of the filling materials and voids between coronal end of the separated instrument and gutta-percha/sealer filled void-free sections. Data was analyzed using Kruskal-Wallis and Mann Whitney-U tests with a significance level of 5%. Kruskal-Wallis revealed differences among groups (p < 0.05).Pairwise comparisons revealed that less volume of voids were measured in SC (0.02 ± 0.03 mm3 ) compared to CLC (0.15 ± 0.16 mm3 ) and TI (0.18 ± 0.24 mm3 ) (p < 0.05); while TI was statistically similar with CLC (p > 0.05). Percentages of volumes of voids and filling materials were as follows for SC, CLC and TI, respectively: 8.88 ± 18.52% and 24.45 ± 38.40%, 46.92 ± 33.53% and 53.07 ± 33.53%, 40.54 ± 33.85% and 42.79 ± 34.45%. The obturation technique may have a significant impact on the volume of voids in the presence of a separated file. No obturation technique produced a void-free root canal filling.

Effect of modified NaOCl irrigation solution on bond strength of bioceramic-based root canal sealer to dentin.

INTRODUCTION: Biomechanical shaping and hermetic obturation play an important role in the success of root canal treatment. AIMS AND OBJECTIVES: This study aimed to examine the bonding strength of the bioceramics sealer to the dentin surface with or without core when irrigated with conventional NaOCl, modified NaOCl, EDTA, MTAD and distilled water. Materials and Methods: 120 single-root teeth dissected at the level of enamel-cement junction were grouped according to different irrigation and filling techniques; each group consisted 12 teeth. After final irrigation with NaOCl, modified NaOCl, EDTA, MTAD or distilled water, the samples were filled with bioceramic sealer. Samples with or without core were obtained; then 2 mm-thickness horizontal sections were made in the middle coronal and the middle third of the dentin and subjected to a push-out test. Results: Although bonding strength was the lowest when modified NaOCl was used, the highest bonding strength was reported with NaOCl in the present study. Bond strength values determined in the coronal third were found to be high compared to the middle third, although the difference was not statistically significant. In the groups without core, the resistance of the connection was found to be higher than in the core with a filled root canal (P < 0.05). CONCLUSION: Because the connection value of the bioceramic root canal sealer to the dentin using modified NaOCl was lower,it is recommended not to use the monoblock effect in canal filling in cases anticipated to be problematic. It would be more appropriate to use bioceramic paste without core in cases where a high attachment to dentin is desired.

A micro-computed tomography evaluation of voids using calcium silicate-based materials in teeth with simulated internal root resorption.

OBJECTIVES: The obturation quality of MTA, Biodentine, Total Fill BC root canal sealer (RCS), and warm gutta-percha (WGP) in teeth with simulated internal root resorption (IRR) was evaluated by using micro-computed tomography. MATERIALS AND METHODS: Standardized IRR cavities were created using 40 extracted maxillary central incisor teeth and randomly assigned into 4 groups (n = 10). IRR cavities were filled with MTA, Biodentine, Total Fill BC RCS (bulk-fill form) and WGP + Total Fill BC RCS. Percentage of voids between resorptive cavity walls and obturation material (external void), and inside the filling materials (internal voids) were measured. RESULTS: Total Fill BC sealer in the bulk-fill form presented significantly highest values of external and internal void percentages (p < 0.05). Biodentine showed a significantly lowest external void percentage (p < 0.05). WGP + Total Fill BC RCS presented significantly lower values of internal void percentages than all groups (p < 0.05), except Biodentine (p > 0.05). CONCLUSION: None of the filling materials were created void-free obturation in resorption cavities. Biodentine may favor its application in teeth with IRR over Angelus MTA and bulk-fill form of Total Fill BC.

Evaluation of the amount of remained sealer in the dentinal tubules following re-treatment with and without solvent.

BACKGROUND: The effect of solvent and sealer type (BioRoot RCS [BRRCS], mineral trioxide aggregate [MTA] Fillapex, and AH26) on the root canal residues was evaluated by confocal laser scanning microscopy (CLSM). MATERIALS AND METHODS: Distal root canals of 60 mandibular molars prepared up to ProTaper-F4 were filled using one of the sealers labeled with 0.1% rhodamine-B (n = 20 per sealer). Samples were divided into two according to reprocessing methods as follows: ProTaper Universal Reprocessing System (PTUR) or solvent plus PTUR. Samples were sectioned at 2-5 and 8 mm from the apex and the samples were observed under CLSM. Penetration depth, percent penetration depth, and percent penetration into canal walls were evaluated. Statistical analysis was performed using the repeated measures of the two-way ANOVA and Bonferroni post hoc test at P = 0.05. RESULTS: The highest penetration depth was measured in BRRCS in all root canal thirds with or without chloroform addition. Percentage of penetration depth values of MTA Fillapex and BRRCS was statistically similar and higher than AH26 in all sections, except the apical section re-treated with the addition of chloroform. CONCLUSION: None of the sealers were completely removed. The type of sealant and the use of chloroform changed the amount of sealant remaining in the root canal system.

Influence of size and insertion depth of irrigation needle on debris extrusion and sealer penetration.

OBJECTIVES: To determine the effect of size and insertion depth of irrigation needle on the amount of apical extruded debris and the amount of penetration depth of sealer using a confocal laser scanning microscope (CLSM). MATERIALS AND METHODS: Twenty maxillary premolars were assigned to 2 groups (n = 10), according to the size of needle tip, 28 G or 30 G. Buccal roots of samples were irrigated with respective needle type inserted 1 mm short of the working length (WL), while palatal roots were irrigated with respective needle type inserted 3 mm short of the WL. Prepared teeth were removed from the pre-weighed Eppendorf tubes. Canals were filled with F3 gutta-percha cone and rhodamine B dye-labeled AH 26 sealer. Teeth were transversally sectioned at 1 and 3 mm levels from the apex and observed under a CLSM. Eppendorf tubes were incubated to evaporate the irrigant and were weighed again. The difference between pre- and post-weights was calculated, and statistical evaluation was performed. RESULTS: Inserting needles closer to the apex and using needles with wider diameters were associated with significantly more debris extrusion (p < 0.05). The position of needles and level of sections had statistically significant effects on sealer penetration depth (p < 0.05 for both). CONCLUSIONS: Following preparation, inserting narrower needles compatible with the final apical diameter of the prepared root canal at 3 mm short of WL during final irrigation might prevent debris extrusion and improve sealer penetration in the apical third.

Postoperative pain intensity after using different instrumentation techniques: a randomized clinical study.

OBJECTIVES: The aim of this clinical study was to evaluate the influence of the instrumentation techniques on the incidence and intensity of postoperative pain in single-visit root canal treatment. MATERIAL AND METHODS: Ninety patients with single root/canal and non-vital pulps were included. The patients were assigned into 3 groups according to root canal instrumentation technique used; modified step-back, reciprocal, and rotational techniques. Root canal treatment was carried out in a single visit and the severity of postoperative pain was assessed via 4-point pain intensity scale. All the participants were called through the phone at 12, 24 and 48 h to obtain the pain scores. Data were analyzed through the Kruskal-Wallis test. RESULTS: There was significant difference between all groups (p<0.05). The modified step-back technique produced postoperative pain significantly lower than the rotational (p=0.018) and reciprocal (p=0.020) techniques. No difference was found between the reciprocal and rotational techniques (p=0.868). Postoperative pain in the first 12 h period (p=0.763) and in the 24 h period (p=0.147) was not significantly different between the groups. However, the difference in the 48 h period was statistically different between the groups (p=0.040). CONCLUSION: All instrumentation techniques caused postoperative pain. The modified step-back technique produced less pain compared to the rotational and reciprocal techniques.

Postoperative pain intensity after using different instrumentation techniques: a randomized clinical study

Abstract Postoperative pain is a frequent complication associated with root canal treatment, especially during apical instrumentation of tooth with preexisting periradicular inflammation Objectives The aim of this clinical study was to evaluate the influence of the instrumentation techniques on the incidence and intensity of postoperative pain in single-visit root canal treatment. Material and Methods Ninety patients with single root/canal and non-vital pulps were included. The patients were assigned into 3 groups according to root canal instrumentation technique used; modified step-back, reciprocal, and rotational techniques. Root canal treatment was carried out in a single visit and the severity of postoperative pain was assessed via 4-point pain intensity scale. All the participants were called through the phone at 12, 24 and 48 h to obtain the pain scores. Data were analyzed through the Kruskal–Wallis test. Results There was significant difference between all groups (p<0.05). The modified step-back technique produced postoperative pain significantly lower than the rotational (p=0.018) and reciprocal (p=0.020) techniques. No difference was found between the reciprocal and rotational techniques (p=0.868). Postoperative pain in the first 12 h period (p=0.763) and in the 24 h period (p=0.147) was not significantly different between the groups. However, the difference in the 48 h period was statistically different between the groups (p=0.040). Conclusion All instrumentation techniques caused postoperative pain. The modified step-back technique produced less pain compared to the rotational and reciprocal techniques.

Influence of passive ultrasonic irrigation on the efficiency of various irrigation solutions in removing smear layer: a scanning electron microscope study.

To evaluate the influence of passive ultrasonic irrigation (PUI) to remove the smear layer with different irrigation solutions. Seventy-eight single rooted mandibular premolars were used. The working lengths were measured and the root canals were prepared by using nickel titanium rotary files. The specimens were subjected to six different irrigation regimens: sodium hypochloride (NaOCl) with classic irrigation (CI); NaOCl with PUI; EDTA with CI; EDTA with PUI; QMix with CI; and QMix with PUI. The specimens were split longitudinally. Scanning electron microscopy images were taken to evaluate the amount of residual smear layer and scored. Statistical analysis was performed with the Kruskal-Wallis test. The Dunn's test was used for post hoc testing after the Kruskal-Wallis test. The smear layer scores of apical thirds were significantly higher than coronal and middle thirds except for NaOCl + CI group (p < 0.001). The irrigation with PUI improved the efficacy of all irrigation solutions on removal of smear layer in both coronal and middle thirds (p < 0.001). The PUI activation increased the activity of NaOCl, EDTA, and QMix, respectively without any significance. All irrigation regimens were significantly more effective in coronal and middle thirds compared to apical third. PUI significantly increased the efficacy of smear layer removal regardless of irrigation solution.

Evaluation of the dentinal wall adaptation ability of MTA Fillapex using stereo electron microscope.

BACKGROUND: An ideal root canal obturation requires a complete dentinal wall adaptation of sealer and Gutta-percha combinations without any gap formations. AIMS: The aim of the study was to evaluate the dentinal wall adaptation ability of MTA Fillapex root canal sealer using stereo electron microscope (SEM). METHODS: Twenty-four, single-rooted, human maxillary incisor teeth were used. All canals were prepared with a rotary nickel-titanium (Ni-Ti) instrument to a size F3 file. Teeth divided into two equal groups and one of the experimental groups was filled with AH Plus, and the other group was filled with MTA Fillapex using Gutta-percha single cone as a core material. The roots were prepared for SEM evaluation, and serial scanning electron photomicrographs were taken at ×50, ×100, ×500, and ×1000 magnifications. The gaps between the root canal sealer and canal walls were detected and measured in coronal, middle, and apical thirds. For each section, the highest value among the detected gap formations was recorded. STATISTICAL ANALYSIS: Mann-Whitney U-test, Freidman, and Wilcoxon tests were used. RESULTS: The statistical analysis showed no significant difference between two sealers in terms of gap formation (P > 0.05). CONCLUSIONS: MTA Fillapex has a similar dentinal wall adaptation ability as AH Plus does.

Cleaning efficacy of reciprocal and rotary systems in the removal of root canal filling material.

AIM: The aim of this study was to compare the efficacy of hand file, nickel titanium rotary instrument, and two reciprocating instruments for removing gutta-percha and sealer from the root canals. MATERIALS AND METHODS: Eighty-eight mandibular premolar teeth were used. The root canals were shaped and filled with gutta-percha and a resin-based sealer. The specimens were divided into four groups according to the technique by which the root filling material was removed: Group 1 - Wave One; Group 2 - Reciproc; Group 3 - ProTaper; and Group 4 - Gates-Glidden burs and stainless steel hand file. Then teeth were split longitudinally and photographed. The images were transferred to a computer. The ratio of remaining filling material to the root canal periphery was calculated with the aid of ImageJ software. Statistical analysis was performed using Kruskal-Wallis and Mann-Whitney tests. RESULTS: A significant difference was found among all groups (P < 0.001). The WaveOne group demonstrated significantly less remaining filling material. The greatest amount of filling material was found in specimens where gutta-percha was removed with Gates-Glidden burs and stainless steel hand file. CONCLUSION: The reciprocating files were found to be significantly more effective in removing the filling material from the canal walls compared to the rotational file and hand file.

Impact of different file systems on the amount of apically extruded debris during endodontic retreatment.

OBJECTIVE: The goal of present study was to determine the effect of different nickel-titanium file systems on the amount of apically extruded debris during endodontic retreatment: D-RaCe retreatment systems, EdgeFile XR retreatment rotary files, and Reciproc R40. MATERIALS AND METHODS: Thirty-six single-rooted prepared mandibular premolar teeth were filled with Gutta-percha and AH Plus sealer. The teeth were then randomly assigned into three groups (n = 12) for retreatment. The endodontic retreatment was performed as follows: D-RaCe, EdgeFile XR, Reciproc 40. Debris extruded apically during the retreatment was collected into preweighed Eppendorf tubes. An incubator was used to store tubes at 70(°) C for 5 days. The initial weight was subtracted from final weight of the Eppendorf tubes to calculate the weight of the dry extruded debris for each group. The data obtained were evaluated using Welch analysis of variance and Games-Howell post-hoc tests (P < 0.05). RESULTS: All files resulted in apical extrusion of debris. Reciproc caused significantly less debris extrusion compared to D-RaCe and EdgeFile XR (P < 0.05). CONCLUSIONS: The findings revealed that during endodontic retreatment, number, and taper of files might have an influence on the amount of apically extruded debris during endodontic retreatment.

Effect of powder-to-water ratio on the push-out bond strength of white mineral trioxide aggregate.

AIM: To evaluate the effect of powder-to-water ratio on the retention characteristics of white mineral trioxide aggregate (MTA; Angelus, Londrina, Pr, Brazil) over time. METHODS: One hundred and thirty-five root dentin slices from extracted single-rooted human mandibular premolar teeth were instrumented to achieve a diameter of 1.3 mm. Three MTA groups were prepared using 4:1, 3:1, and 2:1 powder-to-water ratios. The samples were stored for 96 h and 7 and 28 days at 37°C. The push-out bond strengths were measured using an Instron testing machine. Data were analyzed using two-way analysis of variance (anova) with Bonferroni correction. RESULTS: There was a statistically significant difference between the experimental groups at the 96-h and 7-day study periods (P = 0.002). At 96 h, the materials prepared at 2:1 ratio had the lowest bond strength than the samples prepared at the other two ratios (P < 0.001). There was a significant difference between the findings at 96-h and 28-day study periods for 2:1 and 4:1 ratios. The highest bond strength value was found at 28 days of exposure (P < 0.001). CONCLUSION: The powder-to-water ratio significantly interfered with the bond strength properties of white MTA.

Evaluation of the Bond Strength and Fracture Resistance of Different Post Systems.

AIM: To compare the bond strength and the fracture resistance of different post systems. MATERIALS AND METHODS: Endodontically treated 60 mandibular incisor and 60 mandibular premolar teeth were used for the bond strength and fracture resistance test respectively. For each test, three groups (n = 20) were formed according to the posts used zirconia posts (ZR post), individually formed glass fiber reinforced composite posts with an (Interpenetrating Polymer Network-IPN post) and cast metal posts. Then groups were randomly assigned into two subgroups according to the post design: 1-parallel sided and 2-tapered (n = 10/group). All posts were luted with a self-adhesive luting agent. For push-out test two 1 mm thick horizontal root sections were obtained and subjected to push-out test. For fracture resistance test, the specimens were loaded vertically at 1 mm/min crosshead speed. The push out test data were analyzed with Kruskal-Wallis and Dunn's test. Analysis of variance (ANOVA) and Tukey significant difference tests were used to compare the fracture resistance. RESULTS: Cast metal posts showed the highest retention (p < 0.05); however, IPN and zirconia posts showed similar results. No significant difference was found between parallel sided or tapered designs of post groups in terms of bond strength (p > 0.05). In terms of fracture resistance, IPN post groups showed lowest fracture resistance (p < 0.05). No significant difference was found between parallel sided or tapered posts in terms of fracture resistance, except zirconia post (p > 0.05). There was no relationship between the bond strength and fracture resistance of the post systems (r = - 0.015, p > 0.700). CONCLUSION: Post type had effect both on the fracture resistance and retention of the posts used. However, post design had effect only on the fracture resistance of the post systems. CLINICAL SIGNIFICANCE: Superficial treatment of the post used can improve the retention of post systems.

Apical root canal transportation of different pathfinding systems and their effects on shaping ability of ProTaper Next.

BACKGROUND: This study aimed to compare glide path preparation of different pathfinding systems and their effects on the apical transportation of ProTaper Next (Dentsply Maillefer, Ballaigues, Switzerland) in mesial root canals of extracted human mandibular molars, using digital subtraction radiography. MATERIAL AND METHODS: The mesial canals of 40 mandibular first molars (with curvature angles between 25° and 35°) were selected for this study. The specimens were divided randomly into 4 groups with 10 canals each. Glide paths were created in group 1 with #10, #15 and #20 K-type (Dentsply Maillefer, Ballaigues, Switzerland) stainless steel manual files; in group 2 with Path-File (Dentsply Maillefer) #1, #2, and #3 and in group 3 with #16 ProGlider (Dentsply Maillefer) rotary instruments; in group 4 no glide paths were created. All canals were instrumented up to ProTaper Next X2 to the working length. A double digital radiograph technique was used, pre and post-instrumentation, to assess whether apical transportation and/or aberration in root canal morphology occurred. Instrument failures were also recorded. The data were analyzed statistically using ANOVA and Tukey tests (p<0.05). RESULTS: No significant differences were found among groups regarding apical transportation (p>0.05). Two ProTaper Next instruments failed in-group 4. CONCLUSIONS: Within the parameters of this study, there was no difference between the performance of path-finding files and ProTaper Next system maintained root canal curvature well and was safe to use either with path-finding files or alone. Key words:Glide path, PathFile, ProGlider, ProTaper Next, transportation.

The Effect of Increased Temperatures of QMix and EDTA on the Push-out Bond Strength of an Epoxy-resin Based Sealer.

BACKGROUND: Bond strength of root canal sealers is mainly influenced by the surface tension of the root canal wall. Heat, or the use of a surfactant might reduce surface tension and it is known that surface tension of an EDTA solution significantly affected from temperature rise. QMix is a novel endodontic irrigant for smear layer removal containing EDTA, chlorhexidine and a detergent. There is no data regarding the influence of the temperature of the EDTA and QMix on the push-out bond strength of root canal sealers. AIM: To evaluate effect of temperatures of QMix and EDTA on the bond-strength of AH Plus. MATERIALS AND METHODS: Sixty premolars were prepared with ProTaper F4. During preparation 3% NaOCl was performed. Specimens were divided into 4 groups as follows: 5-mL 17% EDTA at 22°C and 37°C; 5-mL QMix at 22°C and 37°C. Three specimens from each group were prepared for observation using SEM. Remaining roots were obturated and prepared for a push-out test. Data was analysed using Anova and Bonferroni tests (p<0.05). RESULTS: Samples irrigated with QMix had higher push-out bond strength values than those irrigated with EDTA (p=0.01), regardless of temperature. Samples irrigated with 37°C EDTA resulted in higher bond-strength values than those irrigated with 22°C EDTA (p<0.001). CONCLUSION: Temperature of the final irrigant does affect the bond strength values of AH plus to root dentin irrigated with EDTA. Bond strength of AH Plus sealer to root canal dentin may improve with QMix.

Influence of diode laser application on the efficiency of QMiX and EDTA solutions in removing smear layer.

OBJECTIVE: The aim of this study was to compare the efficacy of QMiX and ethylenediaminetetraacetic acid (EDTA) solutions with diode laser treatment in smear layer removal. BACKGROUND DATA: Removing the smear layer from the apical thirds of root canals is difficult, regardless of the solution used. Researchers have been improved some irrigation agitation methods to overcome this challenge, and agitation of irrigants with laser devices has become popular. METHODS: Seventy-five extracted mandibular premolars were used. After root canals were, prepared the specimens were divided into five groups (n = 15): Group 1, no irrigation; Group 2, 17% EDTA; Group 3, QMiX solution; Group 4, 17% EDTA with diode laser; and Group 5, QMiX with diode laser. The roots were split longitudinally and prepared for scanning electron microscopic (SEM) investigation. The smear layer was evaluated under × 500, × 1000, and × 2000 magnifications. RESULTS: The amount of smear layer was found significantly high in the control group (p < 0.001). In the EDTA group, the amount of smear layer was significantly high at the apical thirds, and the differences among the three regions were statistically significant (p < 0.001). In the QMiX group, no difference was found between the coronal and middle thirds; however, the amount of smear layer was significantly high at the apical thirds (p < 0.001). In the EDTA plus laser and the QMiX plus laser groups, the smear layer was found significantly high at the apical thirds (p < 0.001). However, no differences were found between the coronal and middle thirds in either group. CONCLUSIONS: None of the solutions completely removed the smear layer, especially at the apical thirds. Diode laser treatment with solutions decreased the amount of smear layer, without significance.

Effects of Different Rotary Files Combined with Different Irrigation Needles on Apically Extruded Debris.

The aim of this study was to compare the apically extruded debris associated with ProTaper Next and OneShape Apical files using two different irrigation needles, open-ended and closed-ended (Max-I-Probe). Forty-eight mandibular premolars were assigned to four groups (n=12) as follows: Group PTN-SN: Root canal was prepared with ProTaper Next (PTN) and irrigated with open-ended standard needle; Group PTN-MP: Root canal was prepared with PTN and irrigated with Max-I-Probe; Group OSA-SN: Root canal was prepared with OneShape Apical (OSA) and irrigated with open-ended needle; Group OSA-MP: Root canal was prepared with OSA and irrigated with Max-I-Probe. Debris extruded during instrumentation was collected into pre-weighed Eppendorf tubes. After storage in an incubator at 70 °C for 5 days, the Eppendorf tubes were weighed to obtain the final weight with extruded debris. The difference between pre-and post-debris weights was calculated and statistical analysis was performed using Kruskal-Wallis and Mann-Whitney U tests (p<0.05). No statistically significant difference was observed between files and needles regarding amount of apically extruded debris (p>0.05). OneShape Apical and ProTaper Next resulted in extrusion of debris beyond the apical foramen, regardless of needle tip.

Effects of Different Rotary Files Combined with Different Irrigation Needles on Apically Extruded Debris

The aim of this study was to compare the apically extruded debris associated with ProTaper Next and OneShape Apical files using two different irrigation needles, open-ended and closed-ended (Max-I-Probe). Forty-eight mandibular premolars were assigned to four groups (n=12) as follows: Group PTN-SN: Root canal was prepared with ProTaper Next (PTN) and irrigated with open-ended standard needle; Group PTN-MP: Root canal was prepared with PTN and irrigated with Max-I-Probe; Group OSA-SN: Root canal was prepared with OneShape Apical (OSA) and irrigated with open-ended needle; Group OSA-MP: Root canal was prepared with OSA and irrigated with Max-I-Probe. Debris extruded during instrumentation was collected into pre-weighed Eppendorf tubes. After storage in an incubator at 70 °C for 5 days, the Eppendorf tubes were weighed to obtain the final weight with extruded debris. The difference between pre-and post-debris weights was calculated and statistical analysis was performed using Kruskal-Wallis and Mann-Whitney U tests (p<0.05). No statistically significant difference was observed between files and needles regarding amount of apically extruded debris (p>0.05). OneShape Apical and ProTaper Next resulted in extrusion of debris beyond the apical foramen, regardless of needle tip.

O objetivo do presente estudo foi comparar a extrusão apical de restos de preparação de canais, associada às brocas ProTaper Next e OneShape Apical usando duas agulhas de irrigação, de ponta aberta e ponta fechada (Max-I-Probe). Quarenta e oito premolares inferiores foram divididos em quatro grupos (n=12): Grupo PTN-SN: o canal radicular foi preparado com ProTaper Next (PTN) e irrigado com agulha convencional de ponta aberta; Grupo PTN-MP: o canal radicular foi preparado com PTN e irrigado com Max-I-Probe; Grupo OSA-SN: o canal radicular foi preparado com OneShape Apical (OSA) e irrigado com agulha de ponta aberta; Grupo OSA-MP: o canal radicular foi preparado com OSA e irrigado com Max-I-Probe. Os restos extrudados apicalmente foram coletados em tubos Eppendorf previamente pesados. Após armazenagem por cinco dias a 70 °C, os tubos Eppendorf foram pesados para obter o peso final com os resíduos. A diferença entre as pesagens antes e depois foi calculada e análise estatística foi feita usando os testes de Kruskal-Wallis e Mann-Whitney U (p<0,05). Não houve diferença estatisticamente significante entre as brocas e agulhas com relação à quantidade de resíduos extrudados (p>0,05). As brocas ProTaper Next e OneShape Apical promoveram extrusão além do forame apical, independente do tipo de agulha utilizada.