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Clinicians should be aware of all the characteristics and capacities of the instruments that are possible to use when conducting a root canal treatment. The wide variety of nickel-titanium (Ni-Ti) rotary systems on the market and the lack of standardisation of this type of instrument makes the choice in each specific case difficult. Therefore, this review is intended to summarize the characteristics that should be taken into account when choosing one instrument over another. It will be essential to know characteristics, of alloy from which the instrument is made. Moreover, the geometry of the instrument will determine its behaviour, being the mass, the one that marks its resistance to a greater extent. The movement performed by the file is another of the fundamental keys to understand rotary instruments. In conclusion, when performing root canal treatment, the characteristics of the instrument and the tooth must be taken into account, and the operator's own limitations should be known. This paper provides the key points to keep in mind when making this type of treatment.

The aim of this study was to evaluate the effectiveness of smear layer removal after the use of different irrigation methods (passive ultrasonic irrigation (PUI), continuous ultrasonic irrigation (CUI), apical negative pressure irrigation and conventional irrigation) using scanning electron microscopy (SEM) as an analytical tool. A total of 100 single-canal teeth were decoronated and randomly divided into five groups ( n = 20) according to the irrigation method used: conventional irrigation with front outlet syringe, conventional irrigation with lateral outlet syringe, apical negative pressure irrigation (EndoVac), PUI with Irrisafe and CUI with ProUltra PiezoFlow ultrasonic irrigation needle. Root canal preparation was performed with the ProTaper Gold system up to the F4 instrument, and 5.25% NaOCl was used as an irrigant. After chemical-mechanical preparation, the roots were split longitudinally, and the coronal, middle and apical thirds were examined. SEM digital photomicrographs were taken at ×1000 magnification to evaluate the amount of smear layer in each root canal third; CUI significantly removed more smear layer than any other irrigant activation protocol ( p < 0.05); CUI was more effective in removing the smear layer than the other irrigation protocols. However, none of the irrigation protocols were able to produce root canals completely free from smear layer.

Objective: Subgingival dental restorations and periodontal health have been studied for many years; however, there is a low histological evidence on the behavior of new materials in the supracrestal tissue attachment. The aim of this study is to analyze the periodontal response when a tricalcium silicate material (TSM) or composite margin restorations is placed to 0.5 mm and 1.5 mm from the bone crest with a histomorphometric analysis in dogs., Methods: Nine mongrel dogs were used in this study: four dogs (8 canine teeth) for TSM group, 4 dogs (8 canine teeth) for composite group, and 1 dog (2 canine teeth) with cavities without restorations. Cavity preparation of 2×2×1 mm was created on the buccal aspect of the canines at 0.5 and 1.5 mm of the crestal bone. Cavities were restored with composite and TSM or were left unrestored as control. After 12 weeks of healing, the dogs were euthanized and blocks containing the tooth and soft tissues were processed., Results: In all the specimens, the junction epithelium was stablished apical to the tooth preparations. A shorter distance to the bone (0.5 cavity) implies greater apical periodontal migration regardless of the material used. In the TSM groups, the connective tissue height and the distance between bone level and apical margin preparation were greater than those in the composite groups, while the epithelium height was less. However, there were no statistically significant differences comparing TSM and composite groups at either 0.5 mm or 1.5 mm (p > 0.05)., Conclusion: Histologic analysis did not show periodontal reattachment to TSM or composite. In both cases, bone crest migrates apically. For that reason, it is recommended to perform composite restorations at the subgingival level whenever the distance to the bone crest is at least 2 mm., Clinical Relevance: Both composite and TSM do not achieve reinsertion of the connective tissue in the biological width., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Introduction: The aim of this study was to evaluate the influence of rotary (ProTaper Next [PTN; Dentsply Maillefer, Ballaigues, Switzerland] and ProTaper Gold [PTG, Dentsply Maillefer]) and reciprocating (WaveOne Gold [WOG, Dentsply Maillefer]) systems in dentinal microcrack generation after the preparation of curved root canals using micro-computed tomographic analysis., Methods: Twenty-four human mandibular molars with curved roots were scanned in a micro-computed tomographic device using an isotropic resolution of 6.78 μm and randomly assigned into 1 of 3 experimental groups (n = 8) according to the root canal instrumentation system used (PTN, PTG, or WOG). Then, the root canals were prepared up to PTN X2, PTG F2, and WOG Primary instruments in the PTN, PTG, and WOG groups, respectively. After canal preparation, each specimen was scanned again. Pre- and postoperative cross-sectional images of the roots (N = 35,304) were analyzed to identify the presence of dentinal microcracks., Results: Overall, 26% of the images presented dentinal defects (n = 9188). Dentinal microcracks were observed in 24.6%, 26%, and 27.4% of the postinstrumentation images from the PTN, PTG, and WOG groups, respectively. However, all of these dentinal microcracks were already present in the corresponding preoperative images. No new microcracks were generated after the preparation of curved root canals of mandibular molars using the aforementioned systems., Conclusions: Root canal instrumentation with PTN, PTG, and WOG systems did not induce the formation of new dentinal microcracks., (Copyright © 2020 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Background: In this study, the authors assessed the readability of online endodontic information in English and Spanish., Methods: The authors performed a systematic search in Google in May 2016. Search queries were "root canal treatment" and "¿Qué es una endodoncia?" without limits or filters. The authors assessed English readability by using Flesch-Kincaid Reading Grade Level, Flesch Reading Ease Score, Gunning Fog Index, Coleman-Liau index, automated readability index, and Simple Measure of Gobbledygook (SMOG) index. The authors calculated readability for Spanish by using the Fernández-Huerta index and INFLESZ (Ines-Barrio)., Results: The authors assessed the first 100 consecutive sites identified with each search strategy and selected 117 sites. Readability scores for English-language sites were in the category of normal to read, easily understood by 13- through 15-year-old students (Flesch Reading Ease Score, 63, interquartile range (IQR) [53.9-66.2]; Gunning Fog Index, 10.4, IQR [8.8-12]; Coleman-Liau index, 12.5, IQR [11.6-13.3]; and automated readability index, 8.6, IQR [6.7-9.8]). SMOG results led to the estimation that only 7 years of education would be needed to understand these contents (SMOG, 7.6, IQR [6.5-8.8]). Spanish-language sites had a readability index normal for an adult, equivalent to a seventh or eighth school year (Fernandez-Huerta, 62.3, IQR [59.7-66.6]; INFLESZ, 57.5, IQR [55.1-62.1]). The authors found that 36.6% of English-language sites had some degree of difficulty for readers to understand their contents, whereas 23% of Spanish-language sites had some degree of difficulty (14.46; 95% confidence interval, -3.16 to 30.08)., Conclusions: Spanish- and English-language electronic health information about endodontic treatment is acceptable to read, but-particularly for English-language sites-there is an important proportion of sites scoring difficulty levels well above the recommendations., Practical Implications: The internet is a useful tool for communicating with patients, but available endodontic information is difficult for laypeople to understand. Endodontists should produce relevant materials in plain language to overcome this problem., (Copyright © 2018 American Dental Association. Published by Elsevier Inc. All rights reserved.)

Background: One of the causative factors of root defects is the increased friction produced by rotary instrumentation. A high canal curvature may increase stress, making the tooth more susceptible to dentinal cracks. The purpose of this study was to evaluate dentinal micro-crack formation with the ProTaper NEXT and ProTaper Universal systems using LED transillumination, and to analyze the micro-crack generated at the point of maximum canal curvature., Material and Methods: 60 human mandibular premolars with curvatures between 30-49° and radii between 2-4 mm were used. The root canals were instrumented using the Protaper Universal® and Protaper NEXT® systems, with the aid of the Proglider® system. The obtained samples were sectioned transversely before subsequent analysis with LED transillumination at 2 mm and 8 mm from the apex and at the point of maximum canal curvature. Defects were scored: 0 for no defects; and 1 for micro-cracks., Results: Root defects were not observed in the control group. The ProTaper NEXT system caused fewer defects (16.7%) than the ProTaper Universal system (40%) ( P <0.05). The ProTaper Universal system caused significantly more micro-cracks at the point of maximum canal curvature than the ProTaper NEXT system ( P <0.05)., Conclusions: Rotary instrumentation systems often generate root defects, but the ProTaper NEXT system generated fewer dentinal defects than the ProTaper Universal system. A higher prevalence of defects was found at the point of maximum curvature in the ProTaper Universal group. Key words: Curved root, Micro-crack, point of maximum canal curvature, ProTaper NEXT, ProTaper Universal, Vertical root fracture., Competing Interests: Conflict of interest statement:The authors declare that no competing interests exist.

Background: Irrigation of the root canal system is an essential step in the endodontic treatment. The aim of this article is to introduce continuous apical negative-pressure ultrasonic irrigation (CANUI), a new irrigation concept, and compare the characteristics of this new technique with current devices for activating the irrigant., Material and Methods: CANUI is designed for cleaning and disinfecting the root canal system. The device consists of a tube inside another tube that allows the continuous ultrasonic exchange of fresh irrigant, as the irrigant is simultaneously aspirated apically. The coronal and apical tubes are 0.75 and 0.3 mm in diameter, respectively. It is composed of a nickel-titanium microcannula suitable for the working length of curved canals., Results: The CANUI technique has the advantages of apical negative pressure (to avoid apical extrusion of the irrigant) and continuous ultrasonic irrigation (continuous refreshment of the irrigant and forced introduction into the canal ramifications)., Conclusions: The CANUI technique could improve the irrigation technique of dentists to reach more disinfection in endodontic treatments. Key words: Apical negative pressure, continuous ultrasonic irrigation, irrigation in curved canals, irrigation systems., Competing Interests: Conflict of interest statement:The authors deny any conflict of interest.

Background: The efficacy of endodontic irrigation procedures can be compromised by the complexity of the root canal system. Delivering irrigants to the apical third of curved canals presents a particular challenge to endodontists. This study compared the effects of two ultrasonic irrigation techniques on the penetration of sodium hypochlorite into the main canal and simulated lateral canals of curved roots in extracted teeth., Material and Methods: Two sets of simulated lateral canals were created at 2, 4, and 6 mm from the working length in 60 single-rooted teeth (6 canals/tooth, n = 360 canals). The teeth were randomly divided into three experimental irrigation groups: group 1 (n = 20), positive pressure irrigation (PPI); group 2 (n = 20), passive ultrasonic irrigation (PUI); and group 3 (n = 20), continuous ultrasonic irrigation (CUI). To assess the irrigation solution penetration, 20% Chinese ink (Sanford Rotring GmbH, Hamburg, Germany) was added to a 5% sodium hypochlorite solution and delivered into the curved root canals. The penetration of contrast solution into the simulated lateral canals was scored by counting the number of lateral canals (0-2) penetrated to at least 50% of the total length., Results: The CUI group showed significantly higher ( P < 0.05) irrigant penetration into the lateral canals and into the apical third of the main canals. The PPI group showed significantly lower sodium hypochlorite penetration ( P < 0.001) into the main and lateral canals compared with that in the CUI and PUI groups. Significantly higher irrigant penetration was observed in the PUI group than the PPI group., Conclusions: Using CUI as the final rinse significantly increased the penetration of irrigant solution into the simulated lateral canals and apical third of curved roots. Key words: Continuous ultrasonic irrigation, curved root canals, passive ultrasonic irrigation, positive pressure irrigation, root canal irrigation., Competing Interests: The authors deny any confict of interest.

Background: Vertical preparation techniques (VPTs), particularly the biologically oriented preparation technique (BOPT), have gained prominence in restorative dentistry due to their conservative approach to tooth structure preservation and improved aesthetic outcomes. This study aims to assess the knowledge and clinical practices of VPTs, including BOPT, among dental professionals in Sanaa, Yemen, and explore the barriers to their widespread use. Materials and methods: An online cross-sectional survey was conducted among general practitioners and specialists in Sanaa, Yemen using a structured, self-administered questionnaire. The survey explored the participants' knowledge, familiarity, and clinical use of VPTs and their perceptions of its advantages and challenges. Data were analyzed using descriptive statistics and Chi-square tests to evaluate associations between professional roles and VPT knowledge and practice. P values < 0.05 indicated statistical significance. Results: Out of 285 participants, 76.8% were familiar with VPTs but only 11.6% reported using these approaches in clinical practice. The primary source of knowledge acquisition was informal, with 26.3% of the participants citing social media as their main resource. Specialists demonstrated significantly higher proficiency and confidence in applying VPTs compared with general practitioners (p < 0.05). Key challenges identified in clinical adoption were controlling gingival bleeding (32.28%) and achieving precise margins during tooth preparation (34.74%). The majority (55.8%) of participants acknowledged the potential of VPTs as the future of restorative dentistry. Despite these benefits, 36.1% of the respondents emphasized the need for further training and educational programs to enhance proficiency and overcome the perceived complexity of these techniques. Conclusion: This study highlights significant gaps in the knowledge and practice of VPTs, particularly BOPT, among the participants. While these techniques offer promising clinical and aesthetic benefits, their adoption is hindered by inadequate training and perceived complexity. Targeted educational interventions and further research are needed to support the broad implementation of VPTs in clinical practice. Clinical trial number: Not applicable. [ABSTRACT FROM AUTHOR]

Aims: The aim of this study was to assess the smear layer removal efficacy of sodium hypochlorite (NaOCl) and ethylene diamine tetraacetic acid (EDTA), with and without the addition of poloxamer, in an in vitro model. Materials and Methods: In this in vitro study, 60 human premolars were randomly selected and decoronated to standardize the root length to 15 mm. The working length was set 1 mm short of the apex. The canals were instrumented to size F3 using the Protaper file system, with irrigation using NaOCl and saline between instrumentations. The samples were randomly divided into four groups based on the final irrigation protocol: Group 1 (n = 15) - 3% NaOCl with poloxamer, Group 2 (n = 15) - 17% EDTA with poloxamer, Group 3 (n = 15) - 3% NaOCl without poloxamer, and Group 4 (n = 15) - 17% EDTA without poloxamer. All samples were irrigated using an apical negative pressure system, and smear layer removal was analyzed using scanning electron microscopy (SEM). A five-graded scoring system was used to assess smear layer removal. Data were statistically analyzed using the Kruskal-Wallis test. Results: The group irrigated with EDTA and poloxamer showed the most effective smear layer removal, with a median score of 2 in both the middle and apical thirds of the canal. The NaOCl with poloxamer group showed a median score of 3, while the NaOCl-only group had a median score of 5, indicating less efficient removal of the smear layer. Conclusion: The study concluded that the addition of poloxamer to NaOCl and EDTA improved smear layer removal by lowering the surface tension of the irrigants. The combination of EDTA with poloxamer exhibited the best smear layer removal, followed by NaOCl with poloxamer. The NaOCl-only group showed the least effectiveness. This enhanced smear layer removal improves irrigant penetration, particularly for NaOCl, and may also enhance its antimicrobial efficacy. Furthermore, poloxamer's surfactant properties suggest its potential as a drug delivery agent for intracanal medicaments. The results suggest that incorporating poloxamer into root canal irrigation protocols can significantly improve the efficacy of smear layer removal, leading to better irrigation outcomes and improved penetration of medicaments. This could enhance the overall success of endodontic treatments, particularly by improving antimicrobial activity and facilitating more effective drug delivery to the root canal system. Future research could explore the long-term clinical effects of using poloxamer-enhanced irrigants in various root canal systems, as well as investigate its potential as a carrier for additional intracanal medicaments. Further studies should also examine the impact of poloxamer on the mechanical properties of the root canal dentin and its compatibility with other commonly used irrigants. [ABSTRACT FROM AUTHOR]

Prosthodontic treatment of developmental age patients presents a significant challenge to the dentist. The growth and development of the stomatognathic system must be considered in treatment planning. Temporary prosthetic restorations must be regularly inspected and recemented, and final prosthetic restoration should not be delivered until the growth of the body is complete. In addition, due to the complex nature of morphological and functional disorders during the developmental period, simultaneous prosthetic and orthodontic treatment may be required. The case presented in this article is a 16-year-old boy with severe tooth destruction caused by untreated caries disease and poor oral hygiene. The patient required conservative, endodontic, and surgical treatment to restore the occlusion and aesthetics to allow the proper development of the masticatory organ. This article also presents the treatment case of a young patient with damaged crowns in the upper arch, which were restored with standard root–crown posts and cores and temporary 3D-printed composite crowns. [ABSTRACT FROM AUTHOR]

Background: File fracture during root canal treatment in endodontics is a major concern for clinicians. The strength of the file is strongly dependent on its geometry, material, and working conditions; finite element simulations are used to understand these failure mechanisms. One limitation of the models used for these simulations is the approximate geometric representation typically obtained by rotating and scaling a specific cross-section shape along the file length. Given the influence of file geometry on file strength, a more realistic representation based on the manufacturing method is needed. Methods: A computerized method was developed to generate the file geometry by simulating the flute grinding manufacturing process. This method generates the 3D geometry of the file starting from a blank and reproducing the motions of the file and grinding wheel. Results: The cross-section of the resulting geometry does not involve simple rotation and scaling but changes from the shank to the tip. The tilt angle of the grinding wheel affects the final geometry, thus altering the convexity of the cross-section. Several other parameters, such as the pitch and the radius of the grinding disc tip, impact the final geometry. Conclusions: The proposed computational method allows for the generation of endodontic file geometries that match those produced via the actual flute grinding method. This tool may help researchers and tool designers in the preparation of finite element models to assess the strength of realistic files. [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.)

Context: Root canal instrumentation is one of the important procedures for successful endodontic therapy. Unexpected fracture of files occurs during root canal instrumentation without any visible signs of deformation compromising the success of root canal treatment. Aims: The aim of the study was to evaluate and compare cyclic fatigue resistance (CFR) of rotary and reciprocating files in simulated canals with 45°, 60°, and 90° angle of curvature. Settings and Design: The study design was an In vitro study. Subjects and Methods: Sixty nickel-titanium files, 30 each of rotary and reciprocating files were selected and divided into four groups (n = 15) of Neoendo Flex, ProTaper Next, WaveOne Gold (WOG), and Reciproc Blue (RPB) files. Each group was further subdivided into three subgroups containing five samples each based on their use in simulated canals with 45°, 60°, and 90° angle of curvature. To simulate root canals with 45°, 60°, and 90° angle of curvature, three artificial canals were designed in a stainless steel metal block. Each file was autoclaved, immersed in 3% sodium hypochlorite (NaOCl), and coated with 17% ethylenediaminetetraacetic acid (EDTA). Each file was tested for CFR using a torque-controlled reduction handpiece by instrumenting in a simulated canal for 10 s until fracture. The cycle of autoclaving, exposure to NaOCl, EDTA, and testing of CFR for 10 s per canal as per groups and subgroups was repeated again and again until the respective file fracture. The time taken to file fracture was recorded using a digital chronometer. The time taken for each file fracture (in minutes) was multiplied by the number of rotations per minute to attain the number of cycles to failure (NCF). Statistical Analysis Used: The obtained results were subjected to statistical analysis using one-way analysis of variance and independent t-test. Results: One-way ANOVA test showed a statistically significant difference between the four groups, P < 0.001. Independent "t"-test between individual subgroups showed a statistically significant difference, as P < 0.05. Conclusions: WOG and RPB reciprocating file systems showed superior CFR, more especially in canals with abrupt 90° angle of curvature compared to both rotary file systems tested. Among rotary file systems tested, Neoendo Flex showed greater CFR than ProTaper Next. [ABSTRACT FROM AUTHOR]

Aim: To evaluate the propagation of preexisting dentinal microcracks after instrumentation with ProTaper Universal (PTU), ProTaper Gold (PTG), Twisted File Adaptive (TFA), and Reciproc Blue (RB) instruments by micro-CT imaging. Methods: The mesial roots of 60 mature human mandibular molars were cut out approximately 10 mm from the apex. The roots were then divided randomly into four groups (n = 15) based on file system used: PTU, PTG, TFA, and RB. Before and after canal shaping, roots were scanned with micro-CT. The preinstrumentation cross-sectional slices were examined to ascertain the presence of preexisting dentinal microcracks in apical 10 mm of radicular dentine. Postinstrumentation, the extension of preexisting dentinal microcracks was assessed and compared with corresponding preinstrumentation image to determine the grade of propagation. Postinstrumentation, the propagation of preexisting dentinal microcracks were categorized into three grades: nonpropagated dentinal microcracks (Grade 1), incomplete propagation (Grade 2), and complete propagation (Grade 3). Results: The PTU system showed a significantly higher propagation of preexisting dentinal microcracks compared to PTG, TFA, and RB system (P ≤ 0.05). All the instrumentation systems showed propagation of preexisting dentinal microcracks into Grade 2 cracks. Grade 3 propagation was seen in PTU, PTG, and RB systems. The number of Grade 2 dentinal microcracks were significantly higher than Grade 1 dentinal microcracks for the PTU system (P ≤ 0.05). Conclusion: Root canal instrumentation promotes propagation of preexisting dentinal microcracks. As compared to conventional nickel-titanium file systems, reciprocating and thermally treated file systems may less likely result in propagation of dentinal microcracks. [ABSTRACT FROM AUTHOR]

Aim: This study aims to evaluate and compare the efficiency of grapeseed and pineapple extract in removing smear layer from the apical third of root canal, with and without ultrasonic activation. Methods: Eighty single-rooted permanent teeth were divided into two main groups: Group I: conventional syringe irrigation and Group II: ultrasonic activation. Each group was subdivided into two experimental groups, i.e. grapeseed and pineapple extract and one control group, i.e., 17% ethylenediaminetetraacetic acid (EDTA). For each subgroup, instrumentation was done using ProTaper Gold up to size F3 and irrigated with 5 mL of the respective irrigant, followed by a final rinse of 2.5 mL of 5.25% NaOCl. For Group II, the respective irrigant was ultrasonically activated for 1 min, followed by a final rinse of 2.5 mL of 5.25% NaOCl. Smear layer evaluation was done with scanning electron microscope, and data were statistically analyzed. Results: In Group I, both pineapple and grapeseed extracts were more effective than 17% EDTA in removing smear layer from the apical root canal. However, in Group II, 17% EDTA showed highest efficacy in smear layer removal, followed by pineapple and grapeseed extracts (P < 0.05). Conclusion: Natural extracts such as pineapple and grapeseed seeds extracts exhibit potential for smear layer removal in the apical third, without the disadvantage of dentinal erosion from synthetic smear layer removing agents. [ABSTRACT FROM AUTHOR]

Copyright of Masferrer Investiga: Revista Científica de la Universidad Salvadoreña Alberto Masferrer is the property of Universidad Salvadorena Alberto Masferrer 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.)

Objectives: This study aimed to investigate cracked teeth and vertical root fracture observable on micro-CT images of extracted roots of mandibular incisors, after fiber post removal., Materials and Methods: Thirty mandibular incisors were selected with any degree of slight incisal wear inspected with the aid of a stereomicroscope under 12x magnification, in order to have a group of young adult specimens according to the criteria of Hugoson et al. A sample of twelve mandibular incisors were selected, aged between 20 and 30 years old, with similar dentine volume and thickness. The specimens were scanned in a micro-computed tomography (micro-CT) device and submitted to root canal shaping, root canal filling, post space preparation, post placement and post removal., Results: From a total of six experimental endodontic timepoints until post removal of 12 mandibular incisors, 64,800 cross-sectional images were analyzed and no vertical root fracture (VRF) or cracked tooth were detected., Conclusions: Micro-CT assessment after ex vivo fiber post removal did not detect vertical root fracture or cracked tooth formation in the root canal walls of mandibular incisors., Clinical Relevance: This study highlighted that fiber post removal per se was not able to propagate VRF or cracked tooth formation or promoted any interruption of the integrity of human root dentin., Competing Interests: Declarations. Competing interests: The authors declare no competing interests., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Aim: 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., Methodology: 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., Results: 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., Conclusion: 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., (© 2024 British Endodontic Society. Published by John Wiley & Sons Ltd.)

Introduction: The longevity of an endodontically treated tooth depends on fracture resistance by preserving more remaining dentin thickness. The aim of this study is to determine which file system preserves more remaining dentin thickness. Materials and Methods: Protaper universal, M-two, Protaper Next, Trunatomy, I-Race and mandibular first premolar. The removed dentin thickness during instrumentation of each file system was noted by taking the difference of RDT of pre-instrumentation and post-instrumentation with the aid of CBCT. Results and Discussion: TRN [Group-4] shows the least aggressive cutting with maximal preservation of remaining dentin thickness at 3 mm and 6 mm from the apex at both mesiodistal and buccolingual dimensions. M-two [Group-2] shows maximum removed dentin thickness at 3 mm from the apex both mesiodistal dimension and buccolingual dimension. PTU [Group-1] shows maximum removed dentin thickness at 6 mm from the apex at mesiodistal dimension. M-two [Group-2] shows maximum removed dentin thickness at 6 mm from the apex at the buccolingual dimension. Conclusion: In this study, it is concluded that the Trunatomy file system preserves more remaining dentin thickness both mesiodistally and buccolingually both 3 mm and 6 mm from the apex. [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.)

Objective: To compare the effectiveness of lateral canal irrigation penetration by conventional needle, passive ultrasonic, sonic endo activator, and Erbium laser (2780nm). Methods: A total of 40 palatal roots of human maxillary first molars were collected and instrumented at a working length of 12 mm by an X1-X4 rotary Protaper Next system (Dentsply, Maillefer, Ballaigues, Switzerland) using the crown-down technique. Artificial lateral canals were made at 2, 4, and 6 mm from the apex on mesial and distal sides using an ISO rotary reamer (Dentsply, Maillefer, Ballaigues, Switzerland; #10 for mesial, #08 for distal). The samples were then cleared using methyl salicylate. A solution of black ink and normal saline was used as an irrigant for the root canal. The percentages of the penetration of the ink into the lateral canals were measured using a stereomicroscope (Q-Scope, Arnhem, The Netherlands) with the aid of program Image J. The Tukey test is used to assess the significant difference between intragroup and intergroup comparisons of different thirds, and the T-test is used to assess the significant difference between every two groups and for the mesial and distal sides of each group. The level of significance was set at 0.05. Results: Results showed that none of the activation techniques used resulted in complete lateral canal penetrations; however, on both sides at all thirds, the Erbium laser (2780 nm) achieved the highest results with a highly significant statistical difference (p=0.05) with all other groups, and the least penetration was in the conventional needle group. Conclusion: The size of the lateral canal is a restricting factor for all activation methods; the best results can be achieved by laser. Conventional needles cannot be used alone to disinfect complex canal anatomy; however, passive ultrasonic and sonic endo activator activations can produce comparable results. [ABSTRACT FROM AUTHOR]

Background: Performing an appropriate Class II direct restoration is a great challenge. The correct selection of the matrix system and the elements used for its stabilization will have a great impact on the result. The aim of this study is to show a new digital method for a predictable selection of the wedge and compare it with the conventional method. Methods: Sixty patients were randomly divided into two groups. In Group 0, the wedge was selected intraoperatively by visual examination, while in Group 1 the wedge was selected preoperatively through the measurement of the cervical embrasure on the bite-wing radiography. The number of wedges used, modifications to them, and tissue damage were registered, along with the quality of the proximal contact and the marginal adaptation. Results: Student's t-test revealed a statistical difference between the number of wedges used, which was higher in Group 0 (p < 0.05). Pearson Chi-square test showed that tissue damage was statistically higher in Group 0 (p < 0.05), while there was no statistically significant difference between groups in wedge modifications (p > 0.05). Group 1 revealed a higher frequency of satisfactory proximal contact and marginal adaptation (p < 0.05). Conclusions: This new technique reduces wedges waste and tissue damage and provides an adequate interproximal anatomy. [ABSTRACT FROM AUTHOR]

Background: The preparation of the middle mesial (MM) canal of mandibular molars represents a challenge because it is often curved, narrow, and close to the root concave. The purpose of this study was to evaluate the ex vivo shaping ability of 3 nickel-titanium (NiTi) rotary systems in the MM canal using 3D printed resin tooth replicas. Methods: A permanent mandibular first molar with a MM canal was acquired from a pool of extracted teeth and reproduced by a 3D printer. The resin tooth replicas (n = 18) were equally assigned to 3 groups for the evaluation of the shaping abilities of 3 NiTi rotary systems (OneShape [OS], Twisted Files [TF], and ProTaper Gold [PTG]) according to the manufacturer's recommendations. The tooth replicas were scanned by micro-computed tomography (micro-CT) twice before and after instrumentation of the mesiobuccal (MB), mesiolingual (ML), and MM root canals. After 3D reconstruction, the canal straightening, change of root canal volume and surface area, the mesial and distal canal wall thickness and canal transportation at the levels of 1, 2, and 3 mm below furcation were assessed. One-way variance analysis and Turkey's post hoc test were used for comparisons of the means among different groups, and paired-t test was used to compare the mesial and distal sides of the mesial roots. Results: As compared with OS and TF, the use of PTG in preparation of MM canals resulted in significantly more straightening of canal curvature (p < 0.05), greater post-instrumentation canal volume and surface area, and thinner mesial and distal remaining canal wall thickness at 1, 2 and 3 mm below furcation (all p < 0.05). Regarding the root canal transportation in the mesiodistal direction, there was no significant difference among the 3 instruments (all p > 0.05) after the preparation of the MB and ML canals. However, in the MM canal, more pronounced transportation was detected in the PTG group at 2 mm below furcation, and in the TF group at 3 mm below furcation as compared with the other 2 systems (both p < 0.05). Conclusions: 3D printed tooth replicas have the advantages of consistency and can be an ideal model to evaluate the shaping ability of different instruments in the MM canal. OS and TF files performed similarly and both are appropriate for shaping the MM canal, while PTG may cause excessive and uneven resin removal, especially near the furcation, and may lead to root fragility and procedural errors. [ABSTRACT FROM AUTHOR]

The purpose of this narrative review was to discuss the scientific milestones that led to the current understanding of the root dentinal microcrack phenomenon based on the interplay between the usage of micro-computed tomography (micro-CT) as an analytical tool alongside a close-to-mouth experimental model. In 2009, reports on the development of dentinal microcracks in extracted teeth after root canal preparation triggered an awareness of the potential for vertical root fractures (VRFs) of endodontically treated teeth could be developed from defects created by the mechanical stress of nickel-titanium preparation systems on dentine. This assumption was taken for granted, even though no cause-effect relationship had been scientifically demonstrated. Since then, several studies using the sectioning method with extracted teeth have been published and the large discrepancy amongst their outcomes soon become evident. Moreover, the high frequency of reported dentinal microcracks largely contrasted with the clinical incidence of VRFs, raising doubts on their methodological reliability. Using micro-CT technology, it was demonstrated by several studies that, in extracted teeth, dentinal defects already existed before the endodontic procedures, indicating that the initial reports framed a non-existing cause-effect relationship between canal preparation and dentinal microcracks. Although these new findings contributed to a better comprehension of this phenomenon, the misconception that microcracks were the starting point for VRFs was only surpassed with a new in situ approach using fresh cadavers. Surprisingly, microcracks were not identified in sound teeth. As a conclusion, dentinal microcracks in extracted teeth can be considered a non-natural occurrence observed only in a laboratory set-up as a consequence of dehydration and storage conditions. Thus, dentinal microcracks shall not be considered as the starting point for VRFs as they do not manifest in non-extracted teeth. Identifying dentinal microcracks as a laboratory phenomenon highlights the impact of recent scientific developments to disclaim the clinical relevance of laboratory-obtained outcomes., (© 2021 International Endodontic Journal. Published by John Wiley & Sons Ltd.)

Introduction: This study aimed to evaluate the efficacy of the orifice-level passive ultrasonic activation (OL-PUA) technique in removing debris from the mesial root canals of mandibular molars, besides comparing it with other approaches, including manual dynamic agitation (MDA), EndoActivator, and laser-activated irrigation (LAI). Methods: Ninety mesial roots of mandibular molars were prepared up to 25.06 using the Race rotary system, filled with 3% sodium hypochlorite (NaOCl), and then they were randomly assigned to 5 groups (n = 15) based on the activation protocol: MDA, EndoActivator, OL-PUA, LAI (using a diode laser), and needle irrigation (no activation). Moreover, one group served as the negative control using normal saline as the final irrigant. The roots were decalcified and sectioned into coronal, middle, and apical cross-sections. After histological staining, the remaining debris was assessed with an optical microscope and measured in the canals and isthmuses using histomorphometric analysis. Statistical analyses were performed by using oneway ANOVA and Tukey's HSD post hoc test (P = 0.05). Results: Although less residual debris was observed after OL-PUA/LAI than using the EndoActivator/MDA methods, no significant difference was found between the four activation techniques at any root third (P > 0.05). The OL-PUA/LAI group harbored significantly less remaining debris than the needle-irrigated samples at all root thirds (P < 0.05). Debris accumulation increased from the coronal to the apical root thirds. Conclusion: No statistical difference was detected between the four activation techniques in terms of debris-removal performance, and none of them resulted in completely debris-free canals. Orifice-level PUA proved to be a promising approach with significant efficacy in removing debris compared to control groups. [ABSTRACT FROM AUTHOR]

(1) The possibility of knowing information about the anatomy in advance, in particular the arrangement of the endodontic system, is crucial for successful treatment and for avoiding complications during endodontic therapy; the aim was to find a correlation between a minimally invasive and less stressful endodontic access on Ni-Ti rotary instruments, but which allows correct vision and identification of anatomical reference points, simplifying the typologies based on the shape of the pulp chamber in coronal three-dimensional exam views. (2) Based on the inclusion criteria, 104 maxillary molars (52 maxillary first molars and 52 maxillary second molars) were included in the study after 26 Cone Beam Computed Tomography (CBCT) acquisitions (from 15 males and 11 females). And linear measurements were taken with the CBCT-dedicated software for subsequent analysis. (3) The results of the present study show data similar to those already published about this topic. Pawar and Singh's simplified classification actually seems to offer a schematic way of classification that includes almost all of the cases that have been analyzed. (4) The use of a diagnostic examination with a wide Field of View (FOV) and low radiation dose represents an exam capable of obtaining a lot of clinical information for endodontic treatment. Nevertheless, the endodontic anatomy of the upper second molar represents a major challenge for the clinician due to its complexity both in canal shape and in ramification. [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.)

Background: A paucity of Spanish language, culturally relevant parent education materials in the healthcare setting results in suboptimal care for Latinx families and further perpetuates health disparities. The purpose of this article is to describe the process for Spanish translation and cultural adaptations to parent education materials of a parent-centered physical therapy program designed to support maternal mental health and infant development during Neonatal Intensive Care (NICU).Methods: Two bilingual physical therapy (PT) students translated educational materials from English to Spanish and were proofread by a professional translator. Next, we conducted a materials review with 5 members of the Latine Community Review Board (CRB), a "standing" advisory group of natively Spanish-speaking, Latine North Carolinians who contract with research teams under the coordination of the Inclusive Science Program (ISP) of the North Carolina Translational and Clinical Sciences Institute (NC TraCS). Review session recruitment, facilitation, and data analysis were conducted by bilingual NC TraCS project managers and the primary investigator for the main feasibility study. Readability analyses were performed at the final stage of translation and adaptation.Results: Themes from CRB review sessions for improvement included to 1) use parent-friendly language, 2) use the plural masculine form of gendered language for caregivers to include all gender identities in this neonatal context, 3) address challenges with direct translation, and 4) use written education materials to supplement in-person, hands-on training with parents and their infants. All translated materials received a grade level of 5 on the Crawford grade-level index.Conclusion: Based on CRB feedback and readability analysis, the translation and cultural-adaptation process resulted in comprehensible written parent education materials for Spanish-speaking families. Review meetings with the CRB reinforced the need for Spanish materials in the healthcare setting. Further assessment of these materials with Spanish-speaking families in the NICU setting is needed. [ABSTRACT FROM AUTHOR]

Background: Endodontic shaping causes stress and strain in the root canal dentin. Dentin microcracks have the potential to be later followed by root fractures occurring under the occlusal load. The aim of our research was to theoretically determine the values of such dentinal states of stress and strain during the endodontic shaping of curved root canals using finite element analysis (FEA). Methods: To highlight the stress concentrations in dentin, two geometric models were created considering the volume of the curved dental root and the contact between the endodontic file and the root canal walls. The application of forces with different values was simulated both on a uniform curved root canal and on a root canal with an apical third curvature of 25° as they would be applied during the preparation of a root canal. Results: In the case of the first model, which was acted upon with a force of 5 N, the deformations of the root canal appeared along the entire working length, reaching the highest values in the apical third of the root, although there were no geometric changes in the shape of the root canal. Regarding the second root model, with an apical third curvature of 25°, although the applied force was 2 N, the deformations were accompanied by geometric changes in the shape of the root, especially in the upper part of the apical third. At a higher force of 7 N exerted on the endodontic file, the geometric shape changed, and the deformation reached extreme critical values. The resulting tensile stresses appearing in the experimental structure varied similarly to the deformations. Conclusions: Significant stress and strain can develop, especially in the apical third of curved root canals during their shaping, and the risk of cracks is higher for endodontically treated teeth presenting severe curvatures in the apical third of the root. [ABSTRACT FROM AUTHOR]

Dear Editor, In our study, standard needle irrigation was used as a control group. Comparison of different irrigation activation techniques on smear layer removal: an in vitro study. FESEM evaluation of smear layer removal using different irrigant activation methods (EndoActivator, EndoVac, PUI and LAI). [Extracted from the article]

BACKGROUND: Increasingly, marginalized communities are disproportionately facing the worsening effects of environmental hazards, including air pollution, water pollution, and climate change. Language isolation and accessibility has been understudied as a determinant of health. Spanish, despite being the second-most common language in the United States with some 41.8 million speakers, has been neglected among environmental health scientists. Building capacity in high-quality Spanish-language science communication, both for scientific and nonscientific audiences, can yield improvements in health disparities research, public health literacy, international collaborations, and diversity and inclusion efforts. OBJECTIVES: In this article, we discuss the context of language diversity in environmental health sciences and offer recommendations for improving science communication in Spanish. DISCUSSION: English is currently the predominant language for scientific discourse, but Spanish and other non-English languages are routinely used by many environmental health science students and professionals, as well as much of the public. To more effectively conduct and communicate environmental health work in Spanish, we suggest that researchers and scientific institutions a) foster structural changes, b) train emerging scholars and support established researchers, c) tap into community ways of knowing, and d) leverage emerging technologies. [ABSTRACT FROM AUTHOR]

This study aimed to determine the incidence of dentinal microcracks after instrumenting the root canals of maxillary premolars using two novel rotary instrumentation systems. Micro-computed tomography (microCT) scans and images generated by sectioning and observation with a stereomicroscope were used to assess the specimens. Twenty-two freshly extracted maxillary premolars were collected and the specimens were divided into two groups of eleven. The tested radicular shaping systems were XP-Endo shaper and TRUShape (i.e., single file). The specimens were scanned with microCT pre- and post-instrumentation, and the newly formed microcracks were detected. The post-instrumentation scans were also compared with images obtained by sectioning method and stereomicroscope inspection, comparing the incidence of microcracks in either microCT scans or images. The results identified an overall incidence of 0.49% of newly formed microcracks, with no statistically significant differences (p = 0.689) between the shaping systems (0.11% for TRUShape and 0.87% for XP-Endo shaper). There were statistically significant differences (p < 0.001) between the microcracks incidence in microCT scans and the sectioning method (16.6% more for the latter). In conclusion, the results show that neither TRUShape nor XP-Endo shaper created dentinal microcracks during root canal instrumentation. The sectioning method with stereomicroscope evaluation overestimates the presence of microcracks with a statistically significant difference compared to microCT scans. [ABSTRACT FROM AUTHOR]

To that aim, radiographic findings revealed a thickening of the root canal walls and ongoing root development in immature permanent teeth with apical periodontitis undergoing revascularization [[24]]. Additionally, the revascularization of developing permanent teeth with necrotic pulp infection and apical periodontitis or abscesses is encouraged. Endodontic therapy is necessary when caries extend further into the tissues of the tooth and reach the pulp, producing irreparable inflammation or necrosis [[1]]. 26219350 24 El Ashiry E.A., Farsi N.M., Abuzeid S.T., El Ashiry M.M., Bahammam H.A. Dental Pulp Revascularization of Necrotic Permanent Teeth with Immature Apices. [Extracted from the article]

This systematic review aims to establish whether various irrigant activation techniques (IATs) result in greater penetration of irrigant up to the working length. The MEDLINE, Scopus and Cochrane Library electronic databases were searched to determine the difference in irrigant penetration depth in the main canal following the use of manual dynamic activation (MDA), sonic irrigation (SI), passive ultrasonic irrigation (PUI), and apical negative pressure irrigation technique (ANP) in comparison with conventional needle irrigation technique (CNI) in mature permanent teeth. Meta-analysis was performed for straight canals as well as curved canals in addition to subgroup analyses for a) Individual IATs in comparison with CNI, b) Comparison of PUI v ANP and SI v ANP in the straight canals, c) comparison of different IATs performed in straight and curved canals. The outcome was presented as effect size: standardized mean difference (SMD) and percentage difference (% diff) of irrigant penetration up to the working length (WL) alongside 95% confidence intervals using chi-square analysis. Of the 840 records screened, 20 studies were included in the systematic review and 17 studies were included in the meta-analysis. It revealed IATs had significant improvement in irrigant delivery up to the WL in straight (% diff: 51.94%, 95% CI: 39.20-64.67%) and curved canals (SMD: 1.08, 95% CI: 0.64-1.52) over CNI. The subgroup analysis revealed ANP was the most effective and significant technique followed by PUI, SI and MDA techniques in straight canals (% diff: 91.70%, 95% CI: 75.63-107.77%) and curved canals (SMD: 1.45, 95% CI: 0.77-2.13). IATs improve irrigant penetration when compared to CNI technique. In both straight and curved canals, ANP is the most effective in delivering the irrigant up to the WL followed by PUI, SI and MDA techniques. Hence adaptation of recent IATs in routine endodontic practice is recommended. [ABSTRACT FROM AUTHOR]

Irrigation represents a crucial step in endodontics for bacteria disinfection and smear layer removal. Several irrigation strategies have been proposed, although their effects are controversial. This study aims to assess the comparison of four different irrigation systems on the smear layer removal utilizing scanning electron microscopy (SEM). Forty sound monoradicular teeth were collected and casually allocated into four groups (n = 10): Group A, conventional irrigation; Group B, IrriFlex irrigation; Group C, ultrasonic irrigation system; Group D, apical negative pressure irrigation. After chemo-mechanical preparation and longitudinal root separation, the three root thirds were analyzed by SEM. Micrographs were carried out at ×2000 to analyze the smear layer residual in each third of the root canal. Statistically significant differences were found between Group A and Group D (p < 0.05). Groups B and C showed satisfactory results in the coronal and middle thirds, while Group D was the only system that achieved satisfactory results in the apical third. However, the complete smear layer removal in the root canal was never achieved with any of the four systems tested. In conclusion, among the four tested irrigation systems, the greatest efficacy on smear layer removal was reached by Group D. [ABSTRACT FROM AUTHOR]

Purpose: The aim was to determine the effect of different lengths of post-space preparation on the incidence of root crack formation using micro-computed tomography (micro-CT). Methods: Forty-two single and straight-rooted human mandibular premolar teeth were used. Teeth were randomly divided into two groups (n = 21). All teeth were scanned using micro-CT before and after the canal shaping, followed by filling with gutta-percha and a resin-based root canal sealer. Different lengths of post-space (1/2 [Group 1] and 2/3 [Group 2] of the canal length) were prepared for the teeth in Group 1 and Group 2. Teeth were again scanned with micro-CT. Results: After the post-space preparation, no new microcrack formation was observed. As a result of the propagation of microcracks detected in the first scan, completed fractures were detected in 3 teeth in Group 1 and 2 teeth in Group 2. Conclusion: It can be concluded that the different lengths of post-space preparation did not affect the incidence of microcrack formation in root dentin. [ABSTRACT FROM AUTHOR]

Copyright of Balikesir Health Sciences Journal / Balıkesir Sağlık Bilimleri Dergisi is the property of Balikesir Health Sciences Journal (BAUN Health Sci J) 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.)

Objectives: Root canal preparation can lead to cracks on the roots by creating stresses on the root canal walls, which decreases the fracture resistance of the tooth. The present study compared the fracture resistance of the teeth prepared by the ProTaper Universal (PTU), ProTaper Next (PTN), and ProTaper Gold (PTG) rotary file systems. Materials and Methods: Fifty‐six single‐canal premolar teeth were sectioned 14 mm from the root apex. The roots were standardized based on the buccolingual and mesiodistal diameter and randomly assigned to three experimental (n = 14) and one control group (n = 14). The teeth in three experimental groups were instrumented with PTU, PTN, and PTG rotary files. The roots in the control group were not instrumented. A vertical force was applied to each root in a universal testing machine until the root fractured. The data were statistically analyzed by one‐way analysis of variance. Results: There was no significant difference in the fracture resistance of the teeth between the control, PTU, PTN, and PTG groups (p =.115). Conclusions: Root canal preparation with ProTaper files manufactured with conventional NiTi (PTU) and heat‐treated alloys (PTN and PTG) did not affect the fracture resistance of teeth. [ABSTRACT FROM AUTHOR]

The interaction of sodium hypochlorite (NaOCl) and chlorhexidine gluconate (CHX) produces an orange-brown precipitate. The present study evaluated the influence of distilled water (H 2 O) in different irrigation protocols designed to prevent the formation of precipitate with NaOCl and CHX. Fifty canine teeth were instrumented and split longitudinally. The canal was examined with a stereomicroscope and photographed by canal-thirds. The tooth halves were repositioned and distributed randomly into five groups, according to the final irrigation protocol (n = 10): G1 (control)-Ethylenediaminetetraacetic acid (EDTA) + NaOCl + CHX, conventional irrigation (CI); G2-EDTA + NaOCl + CHX, activated with passive ultrasonic irrigation (PUI); G3-EDTA (PUI) + NaOCl (PUI) + H 2 O (CI) + CHX (PUI); G4-EDTA + NaOCl + H 2 O + CHX (PUI); G5-EDTA (PUI) + NaOCl (PUI) + H 2 O (continuous ultrasonic irrigation [CUI]) + CHX (PUI). The specimens were evaluated with a stereomicroscope and scanning electron microscope (SEM). Energy dispersive x-ray spectroscopy analysis was performed to identify the elemental profile of the irrigated canal walls. The images were scored according to the extensiveness of precipitate. Data were analyzed (Kruskal-Wallis test, α = 5%). Under the stereomicroscope, G1 had significantly higher scores than all the other groups in all canal-thirds (p < .05). All four experimental groups showed similar scores (p > .05). There were no significant differences in precipitate formation among root-thirds in intragroup analysis (p > .05). Upon SEM examination, overall, only G5 had lower scores than G1 (p < .05). Analysis by canal-thirds showed no significant difference among groups and among canal-thirds in the intragroup analysis (p > .05). G1 showed high Cl peaks. In-between irrigation with H 2 O activated by CUI is effective in preventing precipitate formation during canal debridement with NaOCl and CHX. RESEARCH HIGHLIGHTS: Continuous ultrasonic irrigation with distilled water was capable to prevent the precipitate formation. The precipitate can be classified as a chemical smear layer., (© 2023 Wiley Periodicals LLC.)

This narrative review will focus on a number of contemporary considerations relating to the restoration of root filled teeth and future directions for research. Clinicians are now more than ever, aware of the interdependence of the endodontic and restorative aspects of managing root filled teeth, and how these aspects of treatment are fundamental to obtaining the best long‐term survival. To obtain the optimal outcomes for patients, clinicians carrying out endodontic treatment should have a vested interest in the restorative phase of the treatment process, as well as an appreciation for the structural and biomechanical effects of endodontic‐restorative procedures on restoration and tooth longevity. Furthermore, the currently available research, largely lacks appreciation of occlusal factors in the longevity of root filled teeth, despite surrogate outcomes demonstrating the considerable influence this variable has. Controversies regarding the clinical relevance of minimally invasive endodontic and restorative concepts are largely unanswered with respect to clinical data, and it is therefore, all too easy to dismiss these ideas due to the lack of scientific evidence. However, conceptually, minimally invasive endodontic‐restorative philosophies appear to be valid, and therefore, in the pursuit of improved clinical outcomes, it is important that the efficacies of these treatment protocols are determined. Alongside an increased awareness of the preservation of tooth structure, developments in adhesive bonding, ceramic materials and the inevitable integration of digital dentistry, there is also a need to evaluate the efficacy of new treatment philosophies and techniques with well‐designed prospective clinical studies. [ABSTRACT FROM AUTHOR]

Dietschi and Spreafico first proposed deep margin elevation (DME) in 1998 to address the multiple clinical problems associated with sub-gingival margins, where sub-gingival margins will be repositioned coronally using composite resin restorations. Given that dentistry is directing towards conservatism, its use is currently trending. Materials and Methods: a search was performed through PubMed, Scopus, and Google Scholar search engines to obtain relevant articles with no time restriction. Results: With biological width taken into consideration, well-defined and polished sub-gingival restorations are compatible with periodontal health. Marginal integrity in the DME technique seems to be affected by the type of adhesive, restoration, and incremental layering of the restoration. Regarding fracture resistance, DME has no significant effects. Conclusion: The DME technique seems to be a minimally invasive alternative to surgical crown lengthening (SCL) and orthodontic extrusion (OE) with respect to biological width. Well-controlled clinical trials are limited in this field; further long-term follow-up studies emphasizing the periodontal outcomes and prevention of complications are needed. [ABSTRACT FROM AUTHOR]

In the present study we evaluated the cytotoxicity of super-oxidized water on human gingival fibroblasts and its efficacy in debris and smear layer removal from root canal walls. Cultured gingival fibroblasts were exposed to super-oxidized water (Sterilox), which was diluted in Iscove's modified Dulbecco's medium (IMDM) at 30%, 40%, 50%, 60% and 70% concentrations. The control group was maintained in IMDM. The cell viability was evaluated by means of an MTT assay after incubation periods of 1 h, 2 h, 24 h and 48 h. Pathological cellular changes were also observed under fluorescence and phase contrast microscopes. The efficacy in debris and smear layer removal was evaluated in comparison to the conventional application of sodium hypochlorite (NaOCl) and ethylenediaminetetraacetic acid (EDTA). Forty maxillary premolars were randomly divided into two equal groups (n = 20) and shaped with ProTaper NEXT rotary instruments using Sterilox or NaOCl/EDTA for irrigation. Afterwards, roots were split longitudinally and examined under a scanning electron microscope. The results revealed that super-oxidized water and sterile distilled water have acceptable biological properties for endodontic applications at concentrations up to 50% (p > 0.05). Moreover, super-oxidized water is equally effective in debris and smear layer removal as compared to NaOCl/EDTA (p > 0.05). [ABSTRACT FROM AUTHOR]

Vertical root fracture (VRF) is a common reason for the extraction of root filled teeth. The accurate diagnosis of VRF may be challenging due to the absence of clinical signs, whilst conventional radiographic assessment is often inconclusive. However, an understanding of the aetiology of VRFs, and more importantly, the key predisposing factors, is crucial in identifying teeth that may be susceptible. Thorough clinical examination with magnification and co‐axial lighting is essential in identifying VRFs, and although CBCT is unable to reliably detect VRFs per se, the pattern of bone loss typically associated with VRF can be fully appreciated, and therefore, increases the probability of correct diagnosis and management. The prevalence of VRFs in root filled teeth is significantly greater than in teeth with vital pulps, demonstrating that the combination of loss of structural integrity, presence of pre‐existing fractures and biochemical effects of loss of vitality is highly relevant. Careful assessment of the occlusal scheme, presence of deflective contacts and identification of parafunctional habits are imperative in both preventing and managing VRFs. Furthermore, anatomical factors such as root canal morphology may predispose certain teeth to VRF. The influence of access cavity design and root canal instrumentation protocols should be considered although the impact of these on the fracture resistance of root filled teeth is not clearly validated. The post‐endodontic restoration of root filled teeth should be expedient and considerate to the residual tooth structure. Posts should be placed 'passively' and excessive 'post‐space' preparation should be avoided. This narrative review aims to present the aetiology, potential predisposing factors, histopathology, diagnosis and management of VRF and present perspectives for future research. Currently, there are limited options other than extraction for the management of VRF, although root resection may be considered in multi‐rooted teeth. Innovative techniques to 'repair' VRFs using both orthograde and surgical approaches require further research and validation. The prevention of VRFs is critical; identifying susceptible teeth, utilizing conservative endodontic procedures, together with expedient and appropriate post‐endodontic restorative procedures is paramount to reducing the incidence of terminal VRFs. [ABSTRACT FROM AUTHOR]