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Aim: This study compared the apical transportation and centering ratio of ProTaper Next (PTN) and XP‐endo Shaper (XPS) nickel titanium (NiTi) rotary files in curved root canals using cone beam computed tomography (CBCT). Methodology: The current in vitro study involved the mesiobuccal canals of mesial roots in 44 extracted mandibular first molars that exhibited apical curvature ranging from 10° to 30°. Two experimental groups were randomly formed from the teeth (n = 22) and subjected to instrumentation with PTN and XPS. CBCT scans were performed before and after instrumentation on the teeth, and the apical transport and centering ratio were calculated at 3, 4, and 5 mm from the apex. Group comparisons were conducted using an independent t‐test with a significance level set at alpha = 0.05. Results: Comparisons within groups did not reveal any statistically significant differences in the magnitude of canal transportation in the buccolingual (BL) and mesiodistal (MD) directions at any level from the apex, neither in the XPS group nor in the PTN group (p > 0.05). Canal transportation in both BL and MD directions was significantly greater in PTN than in XPS (p < 0.05). The centering ratio in the MD and BL directions was the same at 3, 4, and 5 mm from the apex in the PTN (p > 0.05) and also in the XPS (p > 0.05) groups. The centering ratio was significantly higher in XPS than in PTN (p < 0.05) except at 5 mm from the apex in the MD direction and 4 and 5 mm from the apex in the BL direction (p > 0.05). Conclusions: Both buccolingually and mesiodistally, PTN led to greater apical transport than XPS and also showed a lower centering ratio. [ABSTRACT FROM AUTHOR]

Inadequate marginal sealing in endodontically treated teeth can lead to microleakage and treatment failure. The purpose of this in vitro study was to quantify and compare the quality of the marginal seal when different materials and bonding techniques were used to restore endodontic access cavities in zirconia cylinders. Fifty custom zirconia cylinders (10.0 mm in diameter x 14.0 mm in height; wall thickness of 1.5 mm) were prepared with simulated endodontic access cavities (5.0 mm in diameter). The cylindrical specimens were divided into 5 groups, each assigned a different method of access cavity restoration (n = 10 per group): direct glass ionomer cement restorations; direct composite resin restorations adhesively bonded without prior aluminum oxide (AI2O3) particle abrasion of the zirconia surface; direct composite resin restorations adhesively bonded after AI2O3 particle abrasion of the zirconia surface; custom zirconia inlays adhesively bonded without AI2O3 particle abrasion of the zirconia surface or inlay; and custom zirconia inlays adhesively bonded after AI2O3 particle abrasion of the zirconia surface and inlay. Specimens were immersed in 2% methylene blue solution and stored in a humidified incubator at 37°C, and dye penetration was quantified with a spectrophotometer (at 450 nm) every 7 days for 28 days. Statistical analysis was conducted using 2-way analysis of variance with the Tukey test and chi-square analysis. Statistically significant differences in dye penetration were observed, with microleakage influenced by the restoration material and bonding protocol. Zirconia inlays placed after AI2O3 abrasion exhibited the least leakage, showcasing significantly superior sealing compared with direct composite resin restorations without AI2O3 abrasion. The results indicated that AI2O3 particle abrasion is essential for secure bonding of restorations to zirconia. The results of the study confirm that glass ionomer cement should be avoided for long-term restoration of access cavities in zirconia restorations due to its inferior microleakage prevention. Instead, composite resins and zirconia are favored, with AI2O3 air abrasion showing the potential to enhance marginal seal in endodontically treated teeth. [ABSTRACT FROM AUTHOR]

Introduction: The successful outcome of endodontic retreatment heavily relies on the thorough removal of root canal filling materials. This study aimed to quantitatively and qualitatively assess the efficacy of various retreatment file systems using nano-computed tomography (nano-CT) imaging. Materials and Methods: Thirty recently extracted human mandibular molars with mesial roots having curvatures <20° were chosen and sectioned to 16 mm in length. The root canals were prepared with the ProTaper Gold system up to size F2 and they were filled with gutta percha and AH Plus sealer. After obturation, all the samples were randomly assigned to two groups (n = 15 each) for retreatment: Group 1 utilized Solite RE Black retreatment files, while Group 2 employed Coltene HyFlex Remover files. Nano-CT imaging was employed to measure pre- and postoperative volumes of remaining filling material and remaining dentin thickness and the time taken for retreatment was measured in seconds. The obtained values were analyzed statistically (P < 0.05). Results: Nano-CT analysis showed a significant difference (P < 0.05) in the volume of remaining filling material between the Solite RE Black and Coltene HyFlex Remover groups. However, no significant difference was observed in the time required for gutta-percha removal. The Solite RE Black system showed comparatively less dentin removal than the Coltene HyFlex Remover system (P < 0.05). Conclusion: The Solite RE Black retreatment file system demonstrated promising efficacy in removing filling material while preserving dentin integrity compared to the Coltene HyFlex Remover system. These findings support its potential as an effective tool for endodontic retreatment, emphasizing the need for further clinical trials to validate its performance across various clinical scenarios. [ABSTRACT FROM AUTHOR]

Background: This study aims to perform a review by selecting, analyzing, and evaluating articles that discuss the accuracy of intraoral scanners (IOSs) in recording post space compared to conventional impression-making techniques. Methods: The review question framed using the PITR framework (participant, index test, targeted condition, and reference standard) is as follows: What is the dimensional accuracy (T) of impressions made using intraoral scanners (I) for post space (P) compared to impressions made using conventional techniques and digitalized using extraoral scanners (R)? Four electronic databases were searched using pre-set keywords. The guidelines and strategies recommended by PRISMA formed the basis for planning, executing, and documenting this systematic review. QUADAS-2 was used to critically analyze the quality of all the selected articles. Results: After excluding ineligible articles, the end synthesis has nine studies (n = 9) for qualitative analysis. All nine evaluated studies were found to be at risk of bias, with high or unclear risk in one or more domains. Three out of nine evaluated studies had unclear concerns regarding the applicability, and the remaining six had low concerns. In all the included studies, the IOSs were reported to have deviations in accuracy compared to the conventional techniques for making digital impressions of post space. Conclusions: The accuracy of IOSs was found to be inversely proportional to the length of post space and directly proportional to the diameter of post space. IOSs, when used adequately in short post spaces, can be an alternative to conventional impression-making for making custom posts and cores. [ABSTRACT FROM AUTHOR]

The use of motorized nickel titanium instruments is an essential component in contemporaneous clinical endodontics. The mechanical properties of nickel titanium are optimal for the cleaning and shaping of root canal systems. However, instrumentation carries risks, particularly instrument fracture, which may become an obstacle to achieving adequate disinfection of the canal system. Although the biomechanics of instrument fracture have been extensively investigated previously, certain facets remain unexplored, specifically torsional fatigue. This review presents a comprehensive overview of the modern understanding of the biomechanics involved in nickel titanium instrument fracture. Importantly, while research has tended to describe fatigue fracture and torsional failure as distinct and separate entities, clinical conditions are likely a combination of the two. Moreover, intracanal instrument fractures may also occur following a different mechanism, torsional fatigue. This should be taken into consideration for further research and clinical guidance. [ABSTRACT FROM AUTHOR]

Objectives: Preserving the original canal morphology is the ideal goal during root canal preparation. This study aimed to compare canal transportation at various cross-sections using the Neoniti and Wave One Gold rotary systems, both applied with reciprocal motion. Materials and Methods: Forty acrylic S-shape canal simulator endo-blocks were used in this study. Two preparation protocols were applied: (1) Proglider (#16/0.02) followed by Wave One Gold (#20/0.07) and (2) GPS followed by A1#20 (reciprocal motion). The canals were dyed before and after preparation, and images were captured from both stages using blocks. These images were then superimposed using Adobe Photoshop to assess differences, and measurements were taken with Digimizer image analysis software. The data was analyzed using an independent samples T-test, with statistical significance set at P<0.05. Results: Transportation was significantly greater in the middle third of the canal simulator in the group that was treated with Proglider (#16/0.02) followed by Wave One Gold (#20/0.07). However, no significant differences were observed in the coronal or apical thirds. Conclusion: While the manufacturer of Neoniti recommends using this system with continuous rotational motion, it can also be effectively utilized with reciprocal motion, yielding satisfactory results while respecting the canal anatomy. [ABSTRACT FROM AUTHOR]

ABSTRACT: Objective: This study aimed to evaluate the propagation of dentinal microcracks in the mesiobuccal (MB) and mesiolingual (ML) canals following root canal preparation using two different rotary endodontic file systems, TruNatomy (continuous rotation) and MicroMega ONE RECI (reciprocating motion), using micro-computed tomography (micro-CT). Materials and Methods: Fifty freshly extracted human mandibular first and second molars were selected based on specific inclusion criteria. Root canal preparation was confined to the MB and ML canals in mesial roots of mandibular molars (Vertucci Type IV canal configurations) using TruNatomy and MicroMega ONE RECI systems. Pre- and post- preparation scans were taken for all the specimens using micro-CT to identify and measure dentinal microcracks. Statistical analysis was performed using a t-test and Fisher's exact test, with significance set at P < 0.05. Results: The results indicated no statistically significant differences between the two systems in terms of microcrack formation or propagation. In the ML canal, 8.0% of teeth prepared with TruNatomy and 12.0% with MicroMega ONE RECI exhibited microcracks (P = 0.643). In the MB canal, microcracks were found in 12.0% of the TruNatomy group and 8.0% of the MicroMega ONE RECI group (P = 0.643). Both systems showed a significant increase in canal volume, but no significant differences between the instruments (P < 0.001). Conclusion: Both TruNatomy and MicroMega ONE RECI demonstrated similar outcomes regarding dentinal microcrack formation and propagation in the MB and ML canals, with no significant differences. Both systems were effective in enlarging the canals while preserving the natural canal anatomy. These findings suggest that the choice of instrumentation system can be guided by clinical ease and efficiency as both systems offer comparable mechanical effects on dentin integrity during root canal preparation. [ABSTRACT FROM AUTHOR]

Aim Methodology Results Conclusion To investigate the development of dentinal microcracks resulting from the progressive enlargement of the buccal canals of maxillary molars with and without the MB2 canal employing instruments with the same tip and four different tapers.Twenty maxillary molars with (n = 10) and without (n = 10) the MB2 canal underwent micro‐CT scanning. Their mesiobuccal and distobuccal canals were sequentially enlarged using nickel–titanium instruments with sizes 25/.03, 25/.05, 25/.06 and 25/.08v. Subsequent scans were conducted after each canal enlargement. The preoperative scans were coregistered with their respective datasets, and the cross‐sectional images were carefully examined to identify dentinal defects. This process, conducted twice at two‐week intervals, involved two examiners. Intra‐ and inter‐examiner calibrations were validated using the Kappa index. The incidence of microcracks was reported as a percentage frequency.The intra‐ and inter‐examiner Kappa values were 0.85 and 0.88, respectively, indicating excellent agreement. Dentinal microcracks were detected in 1206 out of 42 975 cross‐sectional image slices (2.8%). Molars with MB2 canal exhibited more slices (4.5%) than teeth without MB2 (0.9%). Every dentinal microcrack observed in the images after root canal preparation was already present in the corresponding images taken before root canal preparation.The progressive enlargement of root canals using instruments with different tapers did not induce the formation of new dentinal microcracks in maxillary molars, regardless of the presence of the MB2 canal. [ABSTRACT FROM AUTHOR]

Access cavity preparation represents the initial step in root canal treatment. Minimally invasive approaches have gained increasing attention and involve advancements in the traditional access cavity preparation. Simultaneously, the development of three‐dimensional finite element analysis (3D‐FEA) has provided a theoretical foundation for evaluating the merits and drawbacks of various access cavity preparations. Studies using static loading 3D‐FEA have suggested that conservative access cavity preparation reduces the concentration of stress in the cervical region, thereby strengthening fracture resistance. However, the lack of support from clinical data raises concerns about the validity of this suggestion. Conversely, studies involving cyclic loading 3D‐FEA and dynamic loading 3D‐FEA have challenged the prevailing perspectives by taking into account additional factors such as filling materials, thus providing a more comprehensive understanding of the impact of access cavity preparation on fracture resistance. Existing research lacks a comprehensive comparison of the different 3D‐FEA methods, and this review fills this gap by providing a systematic assessment of different 3D‐FEA methods and their applications in access cavity preparation. [ABSTRACT FROM AUTHOR]

Statement of the Problem: Root canal preparation with rotary files causes dentinal cracks in root canals of primary teeth affecting their longevity. Purpose: Nickel-titanium rotary files have been widely used for root canal preparation in primary teeth. The present study compared occurrence of dentinal microcracks in root canals of extracted primary molar teeth prepared using Hedstrom (H) files, ProTaper Universal rotary files, and ProTaper Next rotary file systems. Materials and Method: In this in vitro experimental study, 80 primary molar mesial root canals were randomly divided into four groups of 20 canals each (n=20). Group I was prepared with H files. Group II was prepared with ProTaper Universal rotary files using shaping files SX and S2. Group III was instrumented with ProTaper Next rotary files X1 and X2 while Group IV was left unprepared and served as control. Roots were stained with 1% methylene blue solution and sectioned perpendicular to the long axis at 2mm, 4mm, and 6mm from the apical foramen. Slices obtained were examined under the stereomicroscope. Data obtained were subjected to statistical analysis using chi square tests. Results: Dentinal microcracks were observed in groups prepared using H files, ProTaper Universal, and ProTaper Next rotary files. Highest percentage of cracked root canals (20%) was seen in Group I, prepared by H files. These cracks were complete in nature, found in apical sections and statistically significant (p= 0.016). Group III prepared with ProTaper Next showed 10% dentinal cracks, followed by ProTaper Universal group with 5% cracked root canals. Conclusion: H files may be considered more aggressive at apical third due to complete cracks produced. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate and compare the shaping abilities and minimum dentin thickness of minimally invasive rotary instruments via micro‐computed tomography. Twelve 3D‐printed C‐shaped canal models from a mandibular molar were divided into two groups, and root canals were prepared with either XP‐endo Rise (XR) or TruNatomy (TN) systems. Pre‐ and post‐preparation evaluations included canal volume, prepared area and minimum dentin thickness. No significant differences were found in canal volume change (XR: 22.66 ± 4.28%, TN: 23.02 ± 5.10%), prepared canal area (XR: 31.86 ± 10.72%, TN: 30.26 ± 11.59%) and minimum dentin thickness (XR: 0.30 ± 0.05 mm, TN: 0.28 ± 0.05 mm) between groups (p > 0.05). The canal volume change in the middle third was significantly higher than that in the coronal and apical thirds (p < 0.05) in both groups. In conclusion, XR demonstrated comparable shaping abilities and minimum dentin thickness to TN in preparing 3D‐printed C‐shaped canals. [ABSTRACT FROM AUTHOR]

Statement of the Problem: Root canal preparation with rotary files causes dentinal cracks in root canals of primary teeth affecting their longevity.Purpose: Nickel-titanium rotary files have been widely used for root canal preparation in primary teeth. The present study compared occurrence of dentinal microcracks in root canals of extracted primary molar teeth prepared using Hedstrom (H) files, ProTaper Universal rotary files, and ProTaper Next rotary file systems.Materials and Method: In this in vitro experimental study, 80 primary molar mesial root canals were randomly divided into four groups of 20 canals each (n=20). Group I was prepared with H files. Group II was prepared with ProTaper Universal rotary files using shaping files SX and S2. Group III was instrumented with ProTaper Next rotary files X1 and X2 while Group IV was left unprepared and served as control. Roots were stained with 1% methylene blue solution and sectioned perpendicular to the long axis at 2mm, 4mm, and 6mm from the apical foramen. Slices obtained were examined under the stereomicroscope. Data obtained were subjected to statistical analysis using chi square tests.Results: Dentinal microcracks were observed in groups prepared using H files, ProTaper Universal, and ProTaper Next rotary files. Highest percentage of cracked root canals (20%) was seen in Group I, prepared by H files. These cracks were complete in nature, found in apical sections and statistically significant (p= 0.016). Group III prepared with ProTaper Next showed 10% dentinal cracks, followed by ProTaper Universal group with 5% cracked root canals.Conclusion: H files may be considered more aggressive at apical third due to complete cracks produced.

Aim: This study aims to compare and evaluate the amount of debris and smear layer remaining on the root canal walls prepared with TruNatomy and ProTaper Next files using scanning electron microscope (SEM). Methods: Sixty freshly extracted maxillary premolar teeth with a single root and oval canals were chosen, and decoronated to a standard length of 15 mm. Samples were randomly divided into three groups (n = 20) and instrumented. Group 1: ProTaper Next files (Dentsply Sirona) till X3, Group 2: Medium-size TruNatomy files (Dentsply Sirona), and Group 3: Gates Glidden drills and hand K files. 2 mL of 5.25% NaOCl was used between instruments. The final irrigation was done using 3 mL of 17% ethylenediaminetetraacetic acid and 3 mL of 5.25% NaOCl with passive ultrasonic agitation for 30 s. Samples were rinsed using distilled water, split mesiodistally, and evaluated under SEM The presence of superficial debris and a smear layer was evaluated using a standard scoring system. Data were statistically analyzed using the Kruskal–Wallis test and the post hoc Dunn’s test, with a level of significance set at P < 0.05. Results: None of the groups demonstrated complete debridement in all three-thirds of the root canal. In both experimental groups, a significant reduction in the amount of debris was seen, whereas there were no significant differences in the smear layer scores. Conclusion: Although ProTaper Next and TruNatomy files performed similarly, utilizing a lesser tapered file system with an optimal irrigation regimen would enhance the debridement ability without unnecessary removal of root dentinal structure.

Objectives: To evaluate the influence of preflaring using LA Axxess and ProTaper Shaping files on the accuracy of Root ZX mini, Mini Apex Locator, and Propex II electronic apex locators (EALs). Methods: Thirty mandibular incisors were accessed, and their root canal length (RCL) was determined with the aid of a stereomicroscope. Then, the specimens were randomly assigned into two groups according to the preflaring instrument: G1- LA Axxess; G2- ProTaper Shaping files. The root canal length was determined in the alginate model by EALs before and after preflaring. Data were classified as accurate (≤ 0.5 mm) or inaccurate (> 0.5 mm or beyond the root canal length). McNemar's test was used to detect differences in the EALs’ accuracy before and after preflaring, and Cochran’s Q test was applied to detect differences in accuracy between the EALs. Results: McNemar's test identified differences in precision in the Propex II and Mini Apex Locator, with significantly increased accuracy after preflaring with ProTaper files. Cochrans’ Q test showed no differences between EALs’ accuracy (p>.05). Conclusions: Preflaring procedures increased accurate measurements for all the EALs, with statistical differences for Propex II and Mini Apex Locator when ProTaper instruments were used. All EALs showed similar accuracy.

The development of rotary files and other endodontic instrument techniques have revolutionised treatment by enhancing canal preparation and producing rounder, smoother canals that are constructed of Nickel-Titanium (NiTi) alloy. There are two types of movements in these instruments: rotary continuous and reciprocating. Rotary continuous movements involve torsion and flexion, and can cause instrument fractures. An alternative approach to avoid the issue is proposed, which involves reciprocating movement. The present literature review compares the incidence of dentinal crack formation in root canal walls when using stainless steel and NiTi rotary systems. It highlights the potential complications, such as tooth fracture and increased bacterial susceptibility due to contact between instruments and dentinal walls.

Introduction: The necessity of using a glide path before the canal preparation is inconclusive. Therefore, this study aimed to assess the shaping ability of two rotary systems in the maxillary first molars’ first mesiobuccal canal (MB1), with or without employing the glide path files. Materials and Methods: The MB1 canals of 100 extracted molars were randomly prepared using either HyFlex EDM (HEDM) or ProTaper Gold (PTG) systems (n = 50 each). Half of the samples in each group were prepared using ProGlider (PG) or HyFlex EDM Glide (HEG). The cone-beam computed tomography scanning was conducted before and after the instrumentation. The canal transportation, centering ability, and remaining dentin thickness were evaluated and compared between the groups using the independent sample t-test and Mann–Whitney U-test (α =0.05). Results: Using HEDM compared to PTG led to greater centering ability at the sub-furcation area (P < 0.05), lower canal transportation at 2 mm below furcation (P = 0.025), and more dentin removed at the middle area (P = 0.011). The systems’ centering ability and canal transportation were comparable when path files were used. Utilizing HEG with HEDM decreased dentin removal at 2 mm below furcation (P = 0.045) and middle area (P = 0.008). Canal preparation with HEDM-HEG caused less dentin removal at 2 mm below furcation than PTG-PG (P = 0.007). Conclusions: The HEDM system outperformed PTG regarding centering ability in the sub-furcation areas and canal transportation 2 mm below the furcation. However, HEDM showed more dentin removal in the middle region than PTG, which was resolved when HEG was used. Therefore, using PathFile with the HEDM system might be suggested.

When selecting an instrument for canal preparation, it is important to consider several parameters that influence the shaping efficiency, including instrument design, metallurgy, and operating motion. This study aimed to evaluate the shaping ability of the ProTaper Next (PTN), WaveOne Gold (WOG), and XP-endo Rise Shaper (XPRS) rotary systems in severely and abruptly curved root canals using cone beam computed tomography (CBCT) and ImageJ software. Forty-eight mesial root canals of the mandibular first molars were assigned equally to three groups: PTN, WOG, and XPRS. Using ImageJ software, CBCT images were acquired pre- and post-instrumentation to assess dentin removal, remaining dentin thickness (RDT), canal transportation, and centering ratio at the coronal, middle, and apical levels. Statistical analyses were conducted on all numerical data. All rotary systems removed significantly more distocoronal dentin in the danger zone (DZ), than the mesiocoronal area. PTN removed significantly more dentin and caused less RDT than XPRS (p < 0.05). However, there were no significant differences between PTN-WOG and WOG-XPRS. In the DZ, the highest percentage of specimens with an RDT < 0.5 mm was observed when using PTN (50%), followed by WOG (31.3%), and XPRS (6.3%). Compared with PTN and WOG, XPRS demonstrated less coronal transportation. Among all rotary systems, there was no significant difference in apical transportation or centering ratio. Based on our observations, all rotary instruments exhibited a tendency to remove dentin in the DZ, but to different degrees. XPRS demonstrated better results in terms of coronal transportation and dentin thickness in the DZ. Comparable centering abilities and minimal apical transportation were demonstrated using all rotary instruments. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to compare the shaping abilities of different nickel-titanium file systems. Materials and Methods: Sixty-six j-shaped resin blocks were randomly divided into three groups (n = 22): Group T-Endo MUST (TE), Group WaveOne (W), Group TruNatomy (TR). After canal preparation, the amount of material removed from the canal, the centering ratio of the file systems, the direction and amount of canal transportation, and shaping errors were evaluated. Shaping time was calculated. Data of shaping time were analyzed with ANOVA and Tamhane test. Data on the shaping ability were analyzed with two- and three-way ROBUST ANOVA. The significance level was set at p = 0.05. Results: There was a statistically significant difference between all groups for shaping time (p < 0.001). There was a statistically significant difference between groups for the total amount of material removed (p < 0.001). The directions of canal transportation were the inner surface of the curvature for W and TR and the outer for TE. There was no statistically significant difference between the groups for the amount of transportation (p > 0.05). The centering ratio of TE and W was statistically higher than TruNatomy (p < 0.001). Conclusions: TruNatomy removed the least material that supported the minimally invasive endodontic approach. All file systems caused similar transportation and did not change the original canal shape. [ABSTRACT FROM AUTHOR]

Background/Objectives: In this article, we present a literature review of methods used to measure the shaping ability of endodontic rotary files, including the selection of endodontic sample type (extracted teeth versus simulated blocks) and an imaging evaluation method. This review was conducted as background research to identify concerns that arise when designing research studies in this domain and propose how the field can plan more systematic studies going forward. Methods: A literature search was conducted using PubMed, MEDLINE, Embase, ScienceDirect, Scopus, and e B-on databases, including studies published in English from January 2010 to June 2024. Only studies that specified in vitro or ex vivo methods for evaluating the endodontic performance of NiTi rotary files on canal transportation and centering ability were considered. Results: A total of 86 studies met the inclusion criteria from an initial pool of 651. Of these, 67 studies used extracted teeth, while 20 utilized simulated root canals in resin blocks. For evaluation methods, 55 studies employed Micro-Computed Tomography and Cone-Beam Computed Tomography (MCT + CBCT), 30 used Double Digital Images/Radiographs/Photographs (DDIR + DDIP) with software analysis, 1 used both DDIR and MCT, 1 used high-precision nano-CT, and 1 used a digital single-lens reflex (DSLR) camera. Conclusions: The findings indicate that the MCT method and its advanced variations appear superior in many cases for evaluating the quality of root canal instrumentation due to their ability to provide detailed three-dimensional images. We also discuss the pros and cons of other evaluation methods, including CBCT and DDIR. Finally, we identify important factors to consider for optimizing future cross-study comparisons. This work highlights the importance of being familiar with shaping ability assessment methods as new instruments are introduced to the market. [ABSTRACT FROM AUTHOR]

Background/Objectives: This study aimed to evaluate the effect of ProDesign Logic files 45.01 and 50.01 on apical foramen wear and shape transformation after foraminal enlargement at tooth length (TL) and 1 mm beyond. Methods: Sixty freshly extracted single-rooted lower human premolars teeth were distributed randomly into five groups (n = 12): Group 1 (40.05 WL) (control): No foraminal enlargement, Group 2 (45.01 TL): Specimens underwent foraminal enlargement with 45.01 Prodesign Logic file at TL; Group 3 (45.01 TL + 1): Specimens underwent foraminal enlargement with 45.01 Prodesign Logic file at 1 mm beyond TL; Group 4 (50.01 TL): Specimens underwent foraminal enlargement with 50.01 Prodesign Logic file at TL; Group 5 (50.01 TL + 1): Specimens underwent foraminal enlargement with 50.01 Prodesign Logic file at 1 mm beyond TL. Scanning electron microscopy was used to evaluate apical foramen variations and shape alterations. Data were analyzed by Student's t-test, Kruskal–Wallis, and Mann–Whitney test. Results: Significant differences (p < 0.01) were observed among all tested groups compared to the control group in terms of the average worn area of the apical foramen. Foraminal enlargement led to significant shape transformation, resulting in round-shaped foramina. Conclusion: ProDesign Logic 45.01 and 50.01 files at TL causes notable wear and round-shaped foramina. [ABSTRACT FROM AUTHOR]

Aim: This study aims to compare and evaluate the amount of debris and smear layer remaining on the root canal walls prepared with TruNatomy and ProTaper Next files using scanning electron microscope (SEM). Methods: Sixty freshly extracted maxillary premolar teeth with a single root and oval canals were chosen, and decoronated to a standard length of 15 mm. Samples were randomly divided into three groups (n = 20) and instrumented. Group 1: ProTaper Next files (Dentsply Sirona) till X3, Group 2: Medium-size TruNatomy files (Dentsply Sirona), and Group 3: Gates Glidden drills and hand K files. 2 mL of 5.25% NaOCl was used between instruments. The final irrigation was done using 3 mL of 17% ethylenediaminetetraacetic acid and 3 mL of 5.25% NaOCl with passive ultrasonic agitation for 30 s. Samples were rinsed using distilled water, split mesiodistally, and evaluated under SEM The presence of superficial debris and a smear layer was evaluated using a standard scoring system. Data were statistically analyzed using the Kruskal–Wallis test and the post hoc Dunn's test, with a level of significance set at P < 0.05. Results: None of the groups demonstrated complete debridement in all three-thirds of the root canal. In both experimental groups, a significant reduction in the amount of debris was seen, whereas there were no significant differences in the smear layer scores. Conclusion: Although ProTaper Next and TruNatomy files performed similarly, utilizing a lesser tapered file system with an optimal irrigation regimen would enhance the debridement ability without unnecessary removal of root dentinal structure. [ABSTRACT FROM AUTHOR]

Introduction: In this study, the cleaning ability of a stainless-steel rotary instrument called Gentlefile, was compared with three nickel-titanium rotary instruments. Materials and Methods: In this in vitro study, forty mandibular single-rooted premolars were randomly assorted into four groups: Gentlefile, ProTper Universal, RaCe files, and XP-Endo Finisher/ProTaper Universal system (n=10). Final instrumentation was done using the aforementioned files with 5.25% sodium hypochlorite and normal saline for root canal irrigation. Debris and smear layers were observed by the scanning electron microscope on the canal walls in the coronal, middle, and apical third of the root level, through a 4-point scoring system. The chi-square test and Kruskal-Wallis were used for data analysis. Results: The Gentlefile demonstrated a promising outcome in smear layer clearance and debris removal compared with the other three rotary systems (P<0.05), specifically at the apical third of the root canal. Based on chi-square test results, there was a significant relationship between root canal cleaning (three levels of cleanliness) in ProTaper Universal (P=0.004) and Gentlefile (P=0.04) groups. Neither of the investigated systems achieved complete cleanliness. Conclusion: The Gentlefile rotary system can be capable of cleaning the apical third of root canals more than the other three groups including Protaper Universal, RaCe, and XP-Endo Finisher. [ABSTRACT FROM AUTHOR]

Background and Objectives: To achieve success in endodontic treatment, it is essential to properly perform the steps of shaping, cleansing and obturation. Determining the working length of the canal is, therefore, a process that must be precise and accurate. Electronic apex locators are a useful tool for the clinician to best perform this step of endodontic treatment. Materials and Methods: The purpose of the following umbrella review is to evaluate, through data in the literature, the degree of accuracy of apex locators. Results: Seven systematic reviews were included in the following umbrella review. Five compare the accuracy of apex locators versus radiographic techniques, two compare different types of electronic apex locators, and two analyze the determination of working length in primary teeth. Conclusions: From the results obtained from the following umbrella review, albeit at low levels of evidence, the methods for determining working length using electronic apex locators and other methods, particularly using radiographic evaluation, are equally valid. [ABSTRACT FROM AUTHOR]

Objective: To analyze the root canal diameter of the mandibular first premolar by using finite element analysis to simulate the stress distribution of dentin under three different preparation methods, and to provide the basis for clinical root canal preparation strategies of the mandibular first premolars. Methods: Twenty-one patients with complete cone beam computed tomography (CBCT) images were selected. The original DICOM format data from CBCT were imported into Mimics 21. 0 software to measure the root canal diameter at 3, 6, 9, and 12 mm from the apex and the root canal taper was segmentally calculated. Based on this, three-dimensional finite element models of the dental and periodontal tissues were constructed. Control group, maximum diameter preparation group, uniform preparation group, and 0. 06 taper instrument preparation group were designed. In ANSYS Workbench 17. 0 finite element analysis software, a 200 N load was applied to the buccal, lingual, and occlusal surfaces in various groups, and the stresses on dentin in various groups were analyzed. Results: The analysis of root canal taper at 3-6 mm, 6-9 mm, and 9-12 mm from the apex of mandibular first premolar teeth showed that the taper was similar in the mesial-distal direction at 3-6 mm from the apex. The average taper in the buccal-lingual direction at 6-9 mm from the apex was 0. 29, which was greater than the taper in the apical 1/3 and coronal 1/3. Under the same load, the peak stress values in dentin of mandibular first premolar teech in various groups were increased sequentially: 4. 693 6, 16. 304 0, 14. 278 0, and 18. 682 0 MPa. The stress in maximum diameter preparation group concentrated on the canal wall with the highest stress value. The stress in uniform preparation group concentrated on the root surface, and the stress values on each section were lower than those in maximum diameter preparation group. The stress in 0. 06 taper instrument preparation group concentrated on the apical 1/3 of the root surface. Conclusion: The root canal of the mandibular first premolar has a unique elliptical taper shape, and there are significant differences in diameter and taper between the mesial-distal and buccal-lingual directions. Different preparation methods result in different stress distributions on the canal wall, and the uniform preparation is the best method for enlarging the canal. [ABSTRACT FROM AUTHOR]

Curved mesial roots can be challenging for different stages of endodontic treatment. Preparation aims to enlarge, clean, and shape the root canal system, and hundreds of systems are available to carry it out. Aiming to maintain pericervical dentin, minimally invasive preparation was proposed, and with it, instruments with lower tapers emerged. This study aimed to evaluate the increase in canal volume, the centering ability of the instruments, and root canal transportation of two different rotary systems with lower tapers. Eighteen curved mesial roots of extracted mandibular molars were scanned by micro-CT at 3 moments: initial and after the 2 stages of endodontic preparation. The canals were prepared using TruNatomy (TN) and ProDesign Logic 2 (PDL2) instruments up to sizes 25.04 and 26.04, respectively, and after 36.03 and 35.05, respectively. The data were analyzed using parametric and nonparametric tests with a significance level of 5%. TN and PDL2 systems showed no difference regarding the increase in the volume of the canals with the first instruments, but after preparation with a diameter size of 35 or 36, there was a difference (P <.01) between the systems in the cervical and middle thirds. Both systems shaped the mesial canals of mandibular molars while keeping low transportation and good centering ability in enlargements up to diameter size 35 or 36 with tapers of 3 or 5%. [ABSTRACT FROM AUTHOR]

Introduction: The necessity of using a glide path before the canal preparation is inconclusive. Therefore, this study aimed to assess the shaping ability of two rotary systems in the maxillary first molars’ first mesiobuccal canal (MB1), with or without employing the glide path files. Materials and Methods: The MB1 canals of 100 extracted molars were randomly prepared using either HyFlex EDM (HEDM) or ProTaper Gold (PTG) systems (n = 50 each). Half of the samples in each group were prepared using ProGlider (PG) or HyFlex EDM Glide (HEG). The cone‑beam computed tomography scanning was conducted before and after the instrumentation. The canal transportation, centering ability, and remaining dentin thickness were evaluated and compared between the groups using the independent sample t‑test and Mann–Whitney U‑test (α =0.05). Results: Using HEDM compared to PTG led to greater centering ability at the sub‑furcation area (P < 0.05), lower canal transportation at 2 mm below furcation (P = 0.025), and more dentin removed at the middle area (P = 0.011). The systems’ centering ability and canal transportation were comparable when path files were used. Utilizing HEG with HEDM decreased dentin removal at 2 mm below furcation (P = 0.045) and middle area (P = 0.008). Canal preparation with HEDM‑HEG caused less dentin removal at 2 mm below furcation than PTG‑PG (P = 0.007). Conclusions: The HEDM system outperformed PTG regarding centering ability in the sub‑furcation areas and canal transportation 2 mm below the furcation. However, HEDM showed more dentin removal in the middle region than PTG, which was resolved when HEG was used. Therefore, using PathFile with the HEDM system might be suggested. [ABSTRACT FROM AUTHOR]

This study assessed the surface topography and plastic deformation (PD) of new and used contemporary reciprocating instruments. Twenty-six WaveOne Gold (WOG) and EdgeOne Fire (EO) instruments were photographed under magnification. The instruments were randomly assigned to a control group of new instruments preserved for surface roughness analysis (n = 6 each), or to an experimental group to shape the root canal system of a single molar (n = 20 each), making a total of four groups (WOGnew, EOnew, WOGused, EOused). Used instruments were also photographed after instrumentation. The presence of fractures was registered. Preoperative and postoperative images were randomly ordered for evaluation. Two blinded calibrated examiners evaluated the presence of PD. Inter-observer agreement was calculated with the Kappa coefficient (K = 0.89). 3D profilometry was also used for the surface roughness analysis of six randomly selected instruments from the WOGused and EOused groups. Chi-square and two-way ANOVA tests were used to, respectively, compare PD and changes in surface roughness among the groups. No instruments fractured; however, a significantly greater percentage of EO instruments suffered plastic deformation than WOG instruments (p < 0.001), (OR = 11.09 (CI 95% 2.6–56.3)). The overall surface roughness was higher for most parameters in the EO instruments (p < 0.05). Single uses of EO instruments produced significantly higher chances of PD and increased surface roughness values compared to WOG. [ABSTRACT FROM AUTHOR]

The development of rotary files and other endodontic instrument techniques have revolutionised treatment by enhancing canal preparation and producing rounder, smoother canals that are constructed of Nickel-Titanium (NiTi) alloy. There are two types of movements in these instruments: rotary continuous and reciprocating. Rotary continuous movements involve torsion and flexion, and can cause instrument fractures. An alternative approach to avoid the issue is proposed, which involves reciprocating movement. The present literature review compares the incidence of dentinal crack formation in root canal walls when using stainless steel and NiTi rotary systems. It highlights the potential complications, such as tooth fracture and increased bacterial susceptibility due to contact between instruments and dentinal walls. [ABSTRACT FROM AUTHOR]

This study assessed the ability of Twisted File Adaptive (TFA), TruNatomy (TRN) and VDW.Rotate (VR) instruments activated by continuous rotation (CR) and adaptive motion (AM) to shape curved root canals. Thirty mandibular molars with two separate mesial canals 20°–40° curved were collected and scanned using micro‐computed tomography (μCT). The canals were then randomly assigned into six groups (n = 10): TRN, VR or TFA instruments activated by CR or AM. TRN groups 17.02, 20.04 and 26.04; VR groups 15.04, 20.05 and 25.06; TFA groups were shaped consecutively using 15K‐file, 20.04 and 25.06. After they were shaped, the canals were scanned again. The volume of removed dentin, canal transportation and centring ratio were calculated μCT images. All data were analysed using the Kruskal–Wallis test or one‐way analysis of variance (p < 0.05). With both kinematics, the TRN instrument removed the least amount of dentin, the VR‐CR and the TFA‐AM removed the most (p < 0.05). The transportation and centring ratios among all groups were similar (p > 0.05). The volume of dentin removed, the diameter or design features of the instruments and different kinematics did not affect the centring ratio and the amount of transportation and remained within safe limits. All three instruments activated by either kinematics were found to have similar effectiveness in shaping curved root canals. [ABSTRACT FROM AUTHOR]

Copyright of Journal of China Medical University is the property of Journal of China Medical University Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Aim: This study aimed determine the influence of the type of root canal instrumentation file systems and obturating materials on the success of pulpectomized teeth. Methods: Two hundred eighty-eight primary molars from children aged 4-7 years were selected and divided into three groups of 96 teeth each. In the first, second, and third groups, root canal instrumentation was performed using Kedo-SG pediatric rotary files (KS), HERO Shaper rotary files (HS), and manual Ni-Ti K-files (MF), respectively. Following instrumentation, these three groups were subdivided into three subgroups of 32 teeth each and obturated using zinc oxide eugenol, Endoflas®, and DiaPex Plus®. The quality of the root filling was assessed immediately and evaluated clinically and radiographically over two years. The Chi-Square Test was used to analyze the data, with the level of significance set at P<0.05. Results: The quality of obturation was superior in root canals instrumented with rotary file systems compared to manual files. No significant difference in obturation quality was noted among the obturating materials used. The clinical success rate after two years was 100%. Radiologically, success rates were 97% for Kedo-SG, 94% for HERO Shaper, and 89% for manual file systems. For obturating materials, the success rates were 90%, 96%, and 94% for zinc oxide eugenol, Endoflas®, and DiaPex Plus®, respectively. Conclusions: The success of pulpectomized teeth was not significantly influenced by the type of root canal instrumentation file systems or the choice of obturating materials. [ABSTRACT FROM AUTHOR]

Objectives: Preserving the original canal morphology is the ideal goal during root canal preparation. This study aimed to compare canal transportation at various cross-sections using the Neoniti and Wave One Gold rotary systems, both applied with reciprocal motion. Materials and Methods: Forty acrylic S-shape canal simulator endo-blocks were used in this study. Two preparation protocols were applied: (1) Proglider (#16/0.02) followed by Wave One Gold (#20/0.07) and (2) GPS followed by A1#20 (reciprocal motion). The canals were dyed before and after preparation, and images were captured from both stages using blocks. These images were then superimposed using Adobe Photoshop to assess differences, and measurements were taken with Digimizer image analysis software. The data was analyzed using an independent samples T-test, with statistical significance set at P

Objective: This study aimed to evaluate the propagation of dentinal microcracks in the mesiobuccal (MB) and mesiolingual (ML) canals following root canal preparation using two different rotary endodontic file systems, TruNatomy (continuous rotation) and MicroMega ONE RECI (reciprocating motion), using micro-computed tomography (micro-CT). Materials and Methods: Fifty freshly extracted human mandibular first and second molars were selected based on specific inclusion criteria. Root canal preparation was confined to the MB and ML canals in mesial roots of mandibular molars (Vertucci Type IV canal configurations) using TruNatomy and MicroMega ONE RECI systems. Pre- and post- preparation scans were taken for all the specimens using micro-CT to identify and measure dentinal microcracks. Statistical analysis was performed using a t-test and Fisher’s exact test, with significance set at P < 0.05. Results: The results indicated no statistically significant differences between the two systems in terms of microcrack formation or propagation. In the ML canal, 8.0% of teeth prepared with TruNatomy and 12.0% with MicroMega ONE RECI exhibited microcracks (P = 0.643). In the MB canal, microcracks were found in 12.0% of the TruNatomy group and 8.0% of the MicroMega ONE RECI group (P = 0.643). Both systems showed a significant increase in canal volume, but no significant differences between the instruments (P < 0.001). Conclusion: Both TruNatomy and MicroMega ONE RECI demonstrated similar outcomes regarding dentinal microcrack formation and propagation in the MB and ML canals, with no significant differences. Both systems were effective in enlarging the canals while preserving the natural canal anatomy. These findings suggest that the choice of instrumentation system can be guided by clinical ease and efficiency as both systems offer comparable mechanical effects on dentin integrity during root canal preparation.

Background: The efficiency and safety of root canal preparation are significantly influenced by the surface topographies of rotary files. Atomic force microscopy (AFM) provides high-resolution imaging that can reveal detailed surface characteristics of these instruments. Materials and Methods: In this study, three types of rotary files (File A, File B, and File C) were used to prepare the root canals of extracted human molar teeth. A total of 30 molar teeth were divided into three groups (n = 10) and prepared using one of the three rotary files. After preparation, the rotary files were analyzed using AFM to measure surface roughness parameters including average roughness (Ra), root mean square roughness (Rq), and maximum peak height (Rp). Statistical analysis was performed using ANOVA and post hoc tests to compare the differences between the groups. Results: The AFM analysis revealed significant differences in the surface topographies of the rotary files. File A exhibited a Ra of 150 nm, a root mean Rq of 180 nm, and a maximum peak height Rp of 300 nm. File B showed an average roughness (Ra) of 200 nm, a root mean Rq of 230 nm, and a maximum peak height (Rp) of 350 nm. File C had an average roughness (Ra) of 170 nm, a root mean Rq of 210 nm, and a maximum Rp of 320 nm. Statistical analysis indicated that File B had significantly higher roughness parameters compared to File A and File C (P < 0.05). Conclusion: The surface topographies of rotary files vary significantly, which may impact their performance in root canal preparation. File B, with the highest roughness parameters, may pose a greater risk of canal wall damage and debris retention. These findings underscore the importance of selecting appropriate rotary files to optimize endodontic treatment outcomes.

Objective: To evaluate the surface defects in Wave One Gold and Jizai rotary files after 1 and 3 uses. Material and Methods: Ninety-six resin blocks with stimulated canals and 12 files per system were used. The files were pre-examined under scanning electron microscopy (SEM) to exclude files with pre-existing cracks and craters. Instrumentation and SEM evaluation of the files were performed after 1 and 3 uses, respectively. Two independent operators analyzed the images, and scoring was carried out for each file's coronal, middle, and apical thirds. The surface defects at different thirds of the file systems were analyzed using the Chi-Square test and Kendel Tau’s test. Results: After one use, both the file systems did not produce any significant surface defects in the coronal, middle, and apical thirds. However, after three uses, there was minor plastic deformation in the coronal and middle thirds of the Wave One Gold file system. Jizai file system did not produce any surface defects in the coronal, middle, and apical thirds. Conclusion: After one use, no surface defects were created in Wave One gold and Jizai rotary files. Wave One Gold exhibited more significant surface defects after three uses in the coronal and middle thirds.

ABSTRACT: Background: The efficiency and safety of root canal preparation are significantly influenced by the surface topographies of rotary files. Atomic force microscopy (AFM) provides high-resolution imaging that can reveal detailed surface characteristics of these instruments. Materials and Methods: In this study, three types of rotary files (File A, File B, and File C) were used to prepare the root canals of extracted human molar teeth. A total of 30 molar teeth were divided into three groups (n = 10) and prepared using one of the three rotary files. After preparation, the rotary files were analyzed using AFM to measure surface roughness parameters including average roughness (Ra), root mean square roughness (Rq), and maximum peak height (Rp). Statistical analysis was performed using ANOVA and post hoc tests to compare the differences between the groups. Results: The AFM analysis revealed significant differences in the surface topographies of the rotary files. File A exhibited a Ra of 150 nm, a root mean Rq of 180 nm, and a maximum peak height Rp of 300 nm. File B showed an average roughness (Ra) of 200 nm, a root mean Rq of 230 nm, and a maximum peak height (Rp) of 350 nm. File C had an average roughness (Ra) of 170 nm, a root mean Rq of 210 nm, and a maximum Rp of 320 nm. Statistical analysis indicated that File B had significantly higher roughness parameters compared to File A and File C (P < 0.05). Conclusion: The surface topographies of rotary files vary significantly, which may impact their performance in root canal preparation. File B, with the highest roughness parameters, may pose a greater risk of canal wall damage and debris retention. These findings underscore the importance of selecting appropriate rotary files to optimize endodontic treatment outcomes. [ABSTRACT FROM AUTHOR]

Abstract Objective Although apex locators are generally effective tools for determining root canal working length, they may produce inaccurate results in some cases. The present study aimed to evaluate the efficacy of ultrasonography as an alternative method for measuring root canal length. Materials and methods Forty-seven anterior teeth with apical lesions were selected for the study. Initially, an electronic apex locator was used to measure the working length. Subsequently, ultrasonography was employed to visualize the root apex and determine the working length. During ultrasound imaging, a K-file No. 15 was inserted into the root canal until its tip was visible on the ultrasound monitor. Measurements obtained from both methods were compared using an independent sample t-test. Correlations were assessed with the Pearson correlation coefficient, and agreement was determined using the Bland‒Altman plot. Results The mean working canal length was 19.9 mm for the apex locator and 20.6 mm for the ultrasonography-guided method. No significant differences were observed between the data obtained using the apex locator method and the data obtained using the ultrasonography guidance method. Furthermore, a high level of agreement was identified between the two techniques. Conclusion Ultrasonography can be used to visualize the apex effectively and determine canal length, especially when canal length determination is uncertain for various reasons.

Aim: This study aimed determine the influence of the type of root canal instrumentation file systems and obturating materials on the success of pulpectomized teeth. Methods: Two hundred eighty-eight primary molars from children aged 4–7 years were selected and divided into three groups of 96 teeth each. In the first, second, and third groups, root canal instrumentation was performed using Kedo-SG pediatric rotary files (KS), HERO Shaper rotary files (HS), and manual Ni-Ti K-files (MF), respectively. Following instrumentation, these three groups were subdivided into three subgroups of 32 teeth each and obturated using zinc oxide eugenol, Endoflas®, and DiaPex Plus®. The quality of the root filling was assessed immediately and evaluated clinically and radiographically over two years. The Chi-Square Test was used to analyze the data, with the level of significance set at P

Objective: This study aimed to evaluate the cleaning efficacy of different rotary systems during root canal treatment.Methods: Forty-five extracted mandibular molars were randomly divided into three groups according to the rotary system applied: Group 1, EDMax; Group 2, EdgeFile X1; and Group 3, Neoniti. The samples were irrigated with 5.25% NaOCl and normal saline as the final rinse. Roots were sectioned longitudinally and examined under scanning electron microscopy (SEM). The debris and smear that remained in the root canals were assessed using a five-score index and compared between groups and root sections. The statistical analysis was performed by Kruskal-Wallis, Friedman, Wilcoxon Signed Ranks, and Mann-Whitney U tests at P < 0.05.Results: There was a statistically significant difference in debris scores between groups at the apical third (P=0.003), but no significant difference was found in other root sections (P>0.05). The sequential rotary EDMax group had more apical debris compared to the single-file reciprocating EdgeFile X1 and single-file rotary Neoniti groups (P< 0.05). No significant difference was observed between the study groups in smear layer scores (P>0.05). However, the smear layer score was significantly greater in the apical than in other root sections in all groups (P

The present study aimed to compare the geometric and mechanical characteristics of six different brands of type K stainless steel manual instruments. Instruments in sizes 15 and 0.20 were analyzed, through buckling and torsional resistance tests, following ISO 3630 standards. -1 and ANSI/ADA 101. Micromorphometry evaluated diameters and conicities at specific points (D0 and D3). The results indicated that the TDK 15 and Angelus 0.20 instruments presented greater resistance to buckling, while variations in diameter in D0 were observed mainly in the TDK 15 and Perfect 15 instruments. In relation to torsional resistance, the Maillefer 0.20 instruments stood out due to the greater angular deflection before fracture, suggesting greater flexibility. Thus, the TDK 15 and Angelus 0.20 instruments proved to be more suitable for negotiating atretic canals and endodontic retreatment, however variations in the diameter of the TDK 15 and Perfect 15 instruments may compromise the adaptation of cones during the obturation phase. The Maillefer 0.20 instruments, with greater flexibility, are more suitable for curved canals.

Introduction: Nickel–titanium instruments annually undergo improvements to enhance the cyclic fatigue lifespan, especially with challenging canals. This study examines RACE EVO instrument in an S-shaped double-curvature canal in different angles of insertion 0°, 20°, and 40° to investigate the behavior of the heat-treated instruments in challenging canals. Materials and Methods: A total of 30 instruments were assigned to three groups (Group 0°, Group 20°, and Group 40°). RACE EVO instruments were tested in artificial canals. The canals had two curvatures: an apical one which its parameters are 70° angle and 2 mm radius and a coronal one which its parameters are 60° angle and 5 mm radius. The test was done using a cyclic fatigue apparatus. A statistical study was done by one-way analysis of variance groups, and Tukey’s honestly significant difference/Tukey–Kramer with a level of significance (α) was adjusted to 0.05. Results: The time until failure was reduced by the increase in the angle of insertion; however, Group 20° and Group 40° were not significantly different. All the instruments were broken apically. The scanning electron microscopic analysis showed typical characteristics of cyclic fatigue failure. Conclusions: Increasing the inclination during the insertion reduced the resistance of the RACE EVO instruments to cyclic fatigue failure despite the surface heat treatment of the instrument.

Introduction: In contemporary dentistry, nickel–titanium (NiTi) rotary instrumentation is the standard of care. General dental practitioners (GDPs) should acquire and adopt rotary root canal instrumentation in their practices. Therefore, this study aimed to investigate the application of rotary root canal instrumentation among GDPs in the Qassim region of Saudi Arabia. Materials and Methods: This cross-sectional survey was conducted in the Qassim region of Saudi Arabia. An online survey was sent to GDPs registered in the Qassim region through the Saudi Dental Society contact list. It consisted of 15 questions about gender, demographics, sector, and the extent of rotary root canal instrumentation adoption in their daily practices. The Chi-square test was used to compare the frequency responses between the groups. Fisher’s exact test was used when the expected outcome was

Objective: Although apex locators are generally effective tools for determining root canal working length, they may produce inaccurate results in some cases. The present study aimed to evaluate the efficacy of ultrasonography as an alternative method for measuring root canal length. Materials and methods: Forty-seven anterior teeth with apical lesions were selected for the study. Initially, an electronic apex locator was used to measure the working length. Subsequently, ultrasonography was employed to visualize the root apex and determine the working length. During ultrasound imaging, a K-file No. 15 was inserted into the root canal until its tip was visible on the ultrasound monitor. Measurements obtained from both methods were compared using an independent sample t-test. Correlations were assessed with the Pearson correlation coefficient, and agreement was determined using the Bland‒Altman plot. Results: The mean working canal length was 19.9 mm for the apex locator and 20.6 mm for the ultrasonography-guided method. No significant differences were observed between the data obtained using the apex locator method and the data obtained using the ultrasonography guidance method. Furthermore, a high level of agreement was identified between the two techniques. Conclusion: Ultrasonography can be used to visualize the apex effectively and determine canal length, especially when canal length determination is uncertain for various reasons. [ABSTRACT FROM AUTHOR]

Background: This is a triple-blinded, prospective split-mouth clinical trial. It is important to shed light on the effect of different apical preparation sizes regarding postoperative pain within the same patient with the same pulpal histological status. The aim is to compare and evaluate the severity of postoperative pain following apical enlargement with two different sizes after the IBF using the visual analogue scale. Methods: Fifty "teeth" in 25 patients were assigned into two equal groups (25 per group) using E3 Azure rotary files; Group A was prepared two sizes greater than the Initial binding file (IBF) (the largest K file to bind at the actual working length) mesial canals, which were enlarged to 35#/0.04 and 40#/0.04 for the distal canals. Group B was prepared in three sizes larger than the IBF: 40#/0.04 for mesial canals and 45#/0.04 for the distal canals. On a modified VAS form, patients were questioned to indicate the degree of their pain and assisted in narrating their pain intensity during the following periods: 12, 24, and 72 h, and after a week. VAS data were non-parametric and analyzed using the signed-rank test for intergroup comparisons, Freidman's test, and the Nemenyi post hoc test for intragroup comparisons. The significance level was set at p < 0.05. Results: showed that regardless of measurement time, enlargement of apical preparation was significantly associated with higher pain scores (p < 0.001). Within both groups, there was a significant reduction of measured pain score with time, with values measured after 12 and 24 h being significantly higher than values measured at other intervals (p < 0.001) and with values measured after three days being significantly higher than 1-week value (p < 0.001). Conclusion: The size of apical preparation had a significant effect on postoperative pain. Trial registration number & date: NCT05847738, 08/05/2023. [ABSTRACT FROM AUTHOR]

Copyright of Turkiye Klinikleri Journal of Dental Sciences is the property of Turkiye Klinikleri and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The diverse morphological configurations in teeth present clinical challenges in root canal treatment, complicating instrumentation and irrigation processes, which can lead to treatment failure. Understanding anatomical variations, such as C-shaped canals and radix entomolaris, enhances clinical skills and improves long-term endodontic treatment success rates. Cone-beam computed tomography (CBCT) offers superior diagnostic capabilities over conventional radiography, enabling the pre-operative detection of root configurations and canal numbers, facilitating personalized endodontic treatments. A total of 2173 teeth of a Mexican population, including 1057 first mandibular molars and 1116 s mandibular molars, were studied using only CBCT to identify C-shaped canals and radix configurations of patients who were treated from 2018 to 2023 at the Department of Radiology at the Faculty of Dentistry, Juarez University of the State of Durango, Mexico. C-shaped canals were identified in 160 teeth, with a prevalence of 0.2% in first mandibular molars and 14.1% in second mandibular molars. The highest frequency was in the left second mandibular molar (3.7) at 14.8%. Gender differences were significant, with higher prevalence in females (27.3%) compared to males (13.3%). The most common C-shaped canal configuration was type C2 (39.3%). Radix entomolaris was found in 52 teeth, with a prevalence of 3.4% in first mandibular molars and 1.4% in second mandibular molars. This research on a Mexican population using cone-beam computed tomography (CBCT) highlights significant findings in the prevalence and types of C-shaped canals and radix entomolaris in mandibular molars for this population. The left second mandibular molar (3.7) showed the highest prevalence at 14.8%, followed closely by the right second mandibular molar (4.7) at 13.5%, with a significant difference (p < 0.001). We found a significant difference in the prevalence of C-shaped canals between genders (p = 0.004, OR 1.78). Additionally, radix entomolaris (p < 0.001) was more frequently identified in first mandibular molars to a significant degree. These insights underscore the importance of CBCT in diagnosing complex root anatomies, which can greatly enhance the success rates of endodontic procedures by allowing for more tailored and precise treatments for this population. [ABSTRACT FROM AUTHOR]

Background.: This investigation assessed the impact of irrigation activation systems on the depth of penetration of intracanal medicaments into dentinal tubules. Methods.: Ninety-six mandibular premolar teeth were prepared using ProTaper Next up to size X3. The teeth were randomly divided into four groups based on the final irrigation activation systems (n=24): group 1: EndoActivator, group 2: XP-Endo Finisher, group 3: Passive ultrasonic irrigation (PUI), and group 4: control. After the final irrigation, all the samples were divided into two subgroups (n=12): subgroup A: calcium hydroxide (Ca(OH)2) and subgroup B: modified triple antibiotic paste (mTAP). Statistical analysis involved three-way analysis of variance (ANOVA). Results.: EndoActivator, XP-Endo Finisher, and PUI activation methods significantly increased the penetration of intracanal medicaments compared to conventional needle irrigation (P <0.05).>P<0.001).>P>0.05). mTAP showed a higher percentage of dentinal tubule penetration than Ca(OH)2, although no significant difference was found in maximum penetration depth. The coronal region demonstrated the highest penetration percentage and depth, while the apical region showed the lowest. Conclusion.: This study showed the effectiveness of XP-Endo Finisher in improving the penetration of intracanal medicaments into dentinal tubules. The findings emphasize the importance of selecting appropriate irrigation activation systems to improve treatment outcomes in endodontics. By demonstrating the effectiveness of advanced systems like XP-Endo Finisher, this research supports their integration into routine clinical practice for better endodontic success. [ABSTRACT FROM AUTHOR]

The efficiency of the endodontic treatment is in direct correlation with the quality of the cleaning, shaping and the obturation of the root canal. In this case, during the cleaning and shaping of the canal, the effectiveness of the irrigation solution is of great importance, which has led to many studies over the decades with several protocols being created in order to potentialize its effectives. The present study seeks to evaluate the cleaning capabilities of two irrigation activator systems, the Easy Clean and the Irrisonic systems [ABSTRACT FROM AUTHOR]

This systematic review and meta‐analysis aimed to determine whether apical patency increases postoperative pain after endodontic therapy. This study explored the degree and incidence of postoperative pain during root canal therapy, as well as the number of required analgesic doses. We searched PubMed, Scopus, Embase, Web of Science, Cochrane Library, and gray literature from the date of database inception until May 2023. RevMan 5.4 software was used for data analysis. Twelve studies were considered eligible for meta‐analysis. The mean pain scores on days 1 (mean difference [MD] = ‐1.69) and 2 (MD = ‐0.85) differed significantly between the apical patency and non‐patency groups. The odds for pain after 24 h were significantly lower (OR 0.59) in the apical patency group than in the non‐patency group. Furthermore, the mean number of required analgesic doses was not significantly different between the two groups. In conclusion, apical patency significantly alleviated postoperative pain (low‐quality evidence) and reduced the incidence of pain (moderate evidence). However, high‐quality randomized controlled trials are required to validate these findings. [ABSTRACT FROM AUTHOR]

Objective: This study aimed to evaluate the cleaning efficacy of different rotary systems during root canal treatment. Methods: Forty-five extracted mandibular molars were randomly divided into three groups according to the rotary system applied: Group 1, EDMax; Group 2, EdgeFile X1; and Group 3, Neoniti. The samples were irrigated with 5.25% NaOCl and normal saline as the final rinse. Roots were sectioned longitudinally and examined under scanning electron microscopy (SEM). The debris and smear that remained in the root canals were assessed using a five-score index and compared between groups and root sections. The statistical analysis was performed by Kruskal-Wallis, Friedman, Wilcoxon Signed Ranks, and Mann-Whitney U tests at P < 0.05. Results: There was a statistically significant difference in debris scores between groups at the apical third (P=0.003), but no significant difference was found in other root sections (P>0.05). The sequential rotary EDMax group had more apical debris compared to the single-file reciprocating EdgeFile X1 and single-file rotary Neoniti groups (P< 0.05). No significant difference was observed between the study groups in smear layer scores (P>0.05). However, the smear layer score was significantly greater in the apical than in other root sections in all groups (P<0.05). Conclusions: The single-file systems, Neoniti and EdgeFile X1, demonstrated superior cleaning efficacy compared to the sequential EDMax system in the apical third, whereas the efficacy of all systems was equivalent in other root areas. Single-file systems may be more effective for root canal cleaning, especially in areas that are more difficult to access. [ABSTRACT FROM AUTHOR]