Search

Introduction: This review aimed to analyze the trend and main characteristics of articles related to guided endodontics (GE)., Methods: The search was conducted in May 2023 on Web of Science. GE-related articles were included, and conferences were excluded. Three researchers selected the articles and extracted: the number of citations; year and journal; design and study theme; authorship and institutions; country and continent. Collaborative networks were generated in the Visualization of Similarities Viewer software. The relationship between data was determined by Spearman's correlation. Google Trends was used to investigate the global popularity of GE research., Results: The search resulted in 135 articles, of which 85 were included. The most cited article totaled 116 citations. The studies were published between 2016 and 2023, most frequently in 2022 (n = 22). The most prevalent journal was the Journal of Endodontics (n = 28). Case report (n = 38) was the most frequent study design. The most studied theme was the use of static GE for calcified canals (n = 27). Connert T was the author with the highest number of articles (n = 13). The University of Basel (n = 9) stood out. The most prevalent country was Brazil (n = 13). Europe was the most frequent continent (n = 38). Visualization of Similarities Viewer demonstrated an interaction between authors. There was a moderate positive correlation between citations and the impact factor (rho = .483). According to Google Trends, the United States was the country that most researched GE., Conclusions: Based on this review, a more significant research interest in GE was observed in Europe, addressing the application of GE in locating severely calcified root canals., (Copyright © 2023 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

The aim of this preliminary study was to evaluate the desirability of alternative models of artificial teeth versus extracted natural teeth for use in preclinical dental education. Specifically, the study was designed to compare the preparation time and perceptions of difficulty of undergraduate dental students and endodontists in carrying out root canal preparations on resin models (both clear and opaque) and extracted natural teeth. Twenty participants-ten fifth-year students at a Brazilian dental school and ten endodontists with at least five years' experience in the specialty-performed root canal instrumentation on two samples of each model. Preparation times were recorded, and the participants completed a questionnaire about the anatomical and physical characteristics of these models. The results showed that the time required for performing endodontic procedures in the natural teeth was higher than in the alternative models. The perceptions of the students and specialists regarding some topics on the questionnaire were significantly different. The students had more positive opinions about artificial teeth made of opaque resin, while the specialists had more positive opinions about simulated root canals in clear resin blocks. This study suggests that neither of the alternative models fulfilled requirements to replace natural teeth in endodontic teaching; improvements are still necessary to accomplish this goal.

Background: Treating tooth root canal systems with Er:YAG laser together with irrigants has been shown to be effective in reducing biofilms formed by Enterococcus faecalis. This study investigated whether laser-activated irrigation (LAI) with side-firing Endo tip (LiteTouch™; Light Instruments, Yokneam, Israel) affects dentin mineral composition when used with common endodontic irrigants. Methods: Root canals of extracted human teeth were treated with Er:YAG laser using a side-firing Endo tip combined with 17% ethylenediaminetetraacetic acid (EDTA) and/or 2.5% NaOCl in continuous or intermittent mode for 60 s. Dentin mineral composition (Ca, P, O) in coronal, middle, and apical regions of root canals was examined by energy dispersive X-ray spectroscopy. Results: The use of LAI with continuous EDTA resulted in the largest reduction in Ca and P levels. A final NaOCl rinse mitigated the EDTA-mediated mineral loss in all root canal regions and increased the O content. Likewise, the reduced Ca/O and Ca/P ratios caused by continuous EDTA irrigation were reversed when combined with a final NaOCl rinse. Conclusions: LAI with Er:YAG Endo tip using continuous EDTA irrigation followed by NaOCl caused minimal dentin mineral loss and can therefore be considered to be a safe treatment module for cleaning root canals. [ABSTRACT FROM AUTHOR]

Key Clinical Message: Due to the complexities and variations of the root canal system's anatomy, mandibular premolars are among the most difficult teeth for endodontic treatment. The lack of clinician knowledge ultimately leads to treatment failure. Mandibular premolars are the most complicated teeth for endodontic treatment because of the variations in root canal anatomy. On the other hand, missing root canals can subsequently lead to failure of endodontic treatment, which causes the patient to become symptomatic. Therefore, the clinician's knowledge of the different types of root canal anatomy and the skill of using new equipment for proper root canal treatment improve the outcome. This study reported the successful endodontic treatment of a mandibular second premolar with four root canals by using an operative microscope. [ABSTRACT FROM AUTHOR]

Background: Treating tooth root canal systems with Er:YAG laser together with irrigants has been shown to be effective in reducing biofilms formed by Enterococcus faecalis. This study investigated whether laser-activated irrigation (LAI) with side-firing Endo tip (LiteTouch™; Light Instruments, Yokneam, Israel) affects dentin mineral composition when used with common endodontic irrigants. Methods: Root canals of extracted human teeth were treated with Er:YAG laser using a side-firing Endo tip combined with 17% ethylenediaminetetraacetic acid (EDTA) and/or 2.5% NaOCl in continuous or intermittent mode for 60 s. Dentin mineral composition (Ca, P, O) in coronal, middle, and apical regions of root canals was examined by energy dispersive X-ray spectroscopy. Results: The use of LAI with continuous EDTA resulted in the largest reduction in Ca and P levels. A final NaOCl rinse mitigated the EDTA-mediated mineral loss in all root canal regions and increased the O content. Likewise, the reduced Ca/O and Ca/P ratios caused by continuous EDTA irrigation were reversed when combined with a final NaOCl rinse. Conclusions: LAI with Er:YAG Endo tip using continuous EDTA irrigation followed by NaOCl caused minimal dentin mineral loss and can therefore be considered to be a safe treatment module for cleaning root canals.

Key Clinical Message Due to the complexities and variations of the root canal system's anatomy, mandibular premolars are among the most difficult teeth for endodontic treatment. The lack of clinician knowledge ultimately leads to treatment failure. Abstract Mandibular premolars are the most complicated teeth for endodontic treatment because of the variations in root canal anatomy. On the other hand, missing root canals can subsequently lead to failure of endodontic treatment, which causes the patient to become symptomatic. Therefore, the clinician's knowledge of the different types of root canal anatomy and the skill of using new equipment for proper root canal treatment improve the outcome. This study reported the successful endodontic treatment of a mandibular second premolar with four root canals by using an operative microscope.

As indicated by standards of modern dentistry, the essence of endodontic treatment is chemo-mechanical disinfection of the root canal system. The vital element of this process is the irrigation of canals with designated solutions as well as activating them. This review article summarizes various techniques of activation of irrigants for endodontic treatment such as manual activation, thermal, pressure, sonic, ultrasonic, and laser techniques in order to compare them. Results were gathered using PubMed, Scopus, Web of Science, and Google Scholar databases by searching keywords: activation, irrigation, irrigation protocols, and sodium hypochlorite. [ABSTRACT FROM AUTHOR]

Copyright of Revista Estomatología is the property of Universidad del Valle 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.)

Apical periodontitis (AP) represents an inflammatory condition of peri-radicular tissues due to invasion and colonization of bacteria in the root canals. Primary apical periodontitis (PAP) is associated with untreated necrotic root canal and can be efficiently treated with endodontic treatment to remove bacteria. Persistent/secondary apical periodontitis (SAP) is a perpetual periapical lesion due to unsuccessfully treated root canals after an initial apparent healing of the tooth. The aim of the study was evaluating the microbial communities associated with root canals using Nanopore sequencing. Seventeen samples from the root canals of 15 patients with AP were Polymerase Chain Reaction-amplified for 16s ribosomal DNA gene and sequenced. Information regarding the presence or absence of AP symptoms, PAP and SAP, and periapical index of patients were recorded. Firmicutes, Bacteroidetes, and Actinobacteria were the most abundant phyla detected and Phocaeicola , Pseudomonas , Rothia , and Prevotella were the most prominent genera. In samples of patients with AP symptoms, the most frequent detected genera were Cutibacterium , Lactobacillus , Pseudomonas , Dialister , Prevotella , and Staphylococcus. In PAP samples, the most represented genera were Cutibacterium , Lactobacillus , Pseudomonas , and Prevotella , whilst in SAP cases were Cutibacterium , Prevotella , Atopobium , Capnocytophaga , Fusobacterium , Pseudomonas , Solobacterium , and Streptococcus. The results provide additional information on the microbiota of root-canals. These data evidence the complexity of the microbiota and the relationship with many clinical and endodontic conditions. Future studies must evaluate these conditions and identify their role in inducing bone damage and local and systemic disease, aiming to better elucidate the relationship between microbes and endodontic pathologies. [ABSTRACT FROM AUTHOR]

As indicated by standards of modern dentistry, the essence of endodontic treatment is chemo-mechanical disinfection of the root canal system. The vital element of this process is the irrigation of canals with designated solutions as well as activating them. This review article summarizes various techniques of activation of irrigants for endodontic treatment such as manual activation, thermal, pressure, sonic, ultrasonic, and laser techniques in order to compare them. Results were gathered using PubMed, Scopus, Web of Science, and Google Scholar databases by searching keywords: activation, irrigation, irrigation protocols, and sodium hypochlorite.

The use of high-tech in endodontics has changed our understanding of the root canal treatment. 3D microscope and diagnostics, ultrasonic, machine tools for processing channels, high-quality irrigation and, finally, a three-dimensional obturation of hot gutta percha. This is the components of a successful endodontic treatment. In the article the clinical case illustrates the possibility of comprehensive application of these technologies. All of the above significantly expands the capabilities of a dentist, which certainly affects the quality of treatment

The mandibular second premolar can be considered one of the most challenging teeth to treat endodontically; due to the complexity of its root canal morphology and increased incidence of multiple canals. The knowledge of internal anatomy of root canals and their possible variations as well as use of magnification, e.g. operating microscope, radiographic examination and illumination, can increase the chances of finding additional canals and contribute to the success of endodontic treatment. The purpose of the current investigation is to report the successful endodontic treatment of a mandibular second premolar with 4 canals; all of them in one single root. [ABSTRACT FROM AUTHOR]

Accurate knowledge of canal anatomy is one of the keys to success when performing root canal treatment. A succuessful outcome depends on three-dimensional debridement and obturation of the root canal system, maintained by a good coronal seal. Intimate knowledge of canal confluency is very important in order to shape the root canal system in the best possible way, and appreciation of uncommon anatomy allows the endodontist to conserve dental tissue. Moreover, using nickel-titanium (NiTi) rotary files, apical confluences and the acute angles of root curvatures often carries a high risk of instrument separation. The aim of this paper is to describe the root canal anatomy of mandibular molars. [ABSTRACT FROM AUTHOR]

OBJECTIVE: To determine the number and morphology of root canals in mandibular third molar teeth in Pakistani population. METHODS: This prospective cross-sectional study was conducted in department of dentistry, Faisalabad Medical University Faisalabad. Sixty(60) patients with irreversible pulpitis in erupted mandibular third molars having age 25-60 years were selected. A total of seventy (70) teeth were evaluated from 1-Jan-2017 to 31-Aug-2017. Periapical x-rays were done in every patient to analyze the number and morphology of root canals. Root canals (RC) were prepared and filling was done using cold lateral compaction technique and restoration was done. After restoration, again x-rays was taken to confirm any missing root canal. RESULTS: The mean age of study patients was 43.2 °6.3 years. There were 37 (61.7%) males and 23 (38.3%) female patients. Regarding number of root canals, 3 root canals were diagnosed in 43 (61.43%) teeth, 4 root canals in 16 (22.86%) teeth and 2 root canals in 8 (11.43%) teeth. Regarding classification of root canals types, type I root canals in 37 (52.86%) teeth, type II in 13 (18.57%) teeth, and type III in 8 (11.43%) teeth. CONCLUSION: Present study results showed that 3 and 4 root canals are most common in our population. [ABSTRACT FROM AUTHOR]

Copyright of dentalTarget is the property of dentalTarget 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.)

Copyright of Journal of Istanbul University Faculty of Dentistry / Istanbul Üniversitesi Dis Hekimligi Fakültesi Dergisi is the property of Istanbul University, Faculty of Dentistry 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.)

Maxillary canines are usually found to be the single-rooted, single-canaled teeth1. Two roots with two root canals are a very rare condition2. Here we report a rare case of anatomic variation of permanent maxillary canine with three roots and three root canals which is first of its kind in the literature. [ABSTRACT FROM AUTHOR]

Cavitation and agitation generated by lasers in fluid-filled root canals create fluid movement and shear stresses along the root canals walls, enhancing removal of the smear layer and biofilm. When used with sodium hypochlorite and EDTA, laser activation of aqueous fluids can increase the efficiency of debridement and disinfection of root canals. However, the use of forward-firing laser fibers with such solutions poses a risk of driving fluid past the root apex, which could cause postoperative complications. The purpose of this study was to evaluate the mechanism of fluid agitation caused by a novel honeycomb tip. Glass capillary tubes filled with distilled water were used to replicate single-tooth root canals. A 980 nm pulsed diode laser was used with 200 μm diameter plain tips, tube-etched conical tips, and honeycomb tips. To record fluid movements, the tubes were backlit and imaged using a digital camera attached to a microscope. The honeycomb tips generated agitation with fluid movement directed onto the walls, while both the conventional plain fibers and the conical tips created fluid movement largely in a forward direction. The use of honeycomb tips alters the pattern of fluid agitation, and this laterally directed effect might lower the risk of fluid extrusion beyond the apex. [ABSTRACT FROM AUTHOR]

Objective: The aim of this ex vivo study was to evaluate the accuracy of endodontic file length measurement on digital periapical radiographs after application of contrast inversion digital enhancement. Materials and Methods: Forty single-rooted single-canal mature permanent human teeth with canals measuring 20-24 mm in length were used in this study. ISO #08 K-files were placed in the root canals of the teeth. The file lengths were measured with a digital caliper as the gold standard. Standard periapical digital images were obtained with the Digora storage phosphor plates and Digora Optime scanner as the original images. The contrast inversion option of Scanora software program version 5.1 was used to produce enhanced images. Three radiologists and three endodontists measured file lengths on the original and enhanced images. The measurements were compared using repeated measures ANOVA and Bonferroni tests (α =0.05). Results: There were significant differences between the measurement accuracy of the original and enhanced images (p<0.05). The enhanced images exhibited longer measurements compared to the original images. However, the two sets of digital radiographs provided significantly longer measurements compared to the gold standard (p<0.05). Conclusion: The contrast inversion tool of Scanora software program decreases measurement accuracy of the length of small endodontic files on digital periapical radiographs. It is suggested that contrast inversion should not be used in determining the lengths of small endodontic files. [ABSTRACT FROM AUTHOR]

The aim of this preliminary study was to evaluate the desirability of alternative models of artificial teeth versus extracted natural teeth for use in preclinical dental education. Specifically, the study was designed to compare the preparation time and perceptions of difficulty of undergraduate dental students and endodontists in carrying out root canal preparations on resin models (both clear and opaque) and extracted natural teeth. Twenty participants--ten fifth-year students at a Brazilian dental school and ten endodontists with at least five years' experience in the specialty--performed root canal instrumentation on two samples of each model. Preparation times were recorded, and the participants completed a questionnaire about the anatomical and physical characteristics of these models. The results showed that the time required for performing endodontic procedures in the natural teeth was higher than in the alternative models. The perceptions of the students and specialists regarding some topics on the questionnaire were significantly different. The students had more positive opinions about artificial teeth made of opaque resin, while the specialists had more positive opinions about simulated root canals in clear resin blocks. This study suggests that neither of the alternative models fulfilled requirements to replace natural teeth in endodontic teaching; improvements are still necessary to accomplish this goal. [ABSTRACT FROM AUTHOR]

Nonsurgical endodontic therapy of a right maxillary first molar with three roots and seven root canals. This unusual morphology was diagnosed using a dental operating microscope (DOM) and confirmed with the help of cone-beam computed tomography (CBCT) images. CBCT axial images showed that both the palatal and distobuccal root have a Vertucci type II canal pattern, whereas the mesiobuccal root showed a Sert and Bayirli type XVIII canal configuration. The use of a DOM and CBCT imaging in endodontically challenging cases can facilitate a better understanding of the complex root canal anatomy, which ultimately enables the clinician to explore the root canal system and clean, shape, and obturate it more efficiently. [ABSTRACT FROM AUTHOR]

Copyright of Revista Facultad de Odontología Universidad de Antioquia is the property of Universidad de Antioquia 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 anatomy of the root canal system is so uncertain that none can successfully predict the number of root and root canals in tooth. Variation in morphology is very common. A successful endodontic therapy is the one where such variations can be detected, cleaned, shaped and obturated. This article discusses various methods for detection of extra canals. [ABSTRACT FROM AUTHOR]

Abstract: Introduction: Root canal treatment of maxillary molars presenting with complex root canal configurations can be diagnostically and technically challenging. Methods: Nonsurgical endodontic therapy of a left maxillary first molar with three roots and eight root canals was successfully performed. This unusual morphology was diagnosed using a dental operating microscope (DOM) and confirmed with the help of cone-beam computed tomography (CBCT) images. Results: CBCT axial images showed that both the mesiobuccal and distobuccal root contained a Sert and Bayirli type XV canal, whereas the palatal root showed a Vertucci type II canal configuration. Conclusions: The use of a DOM and CBCT imaging in endodontically challenging cases can facilitate a better understanding of the complex root canal anatomy, which ultimately enables the clinician to explore the root canal system and clean, shape, and obturate it more efficiently. [Copyright &y& Elsevier]

Copyright of Revista ADM is the property of Asociacion Dental Mexicana 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.)

Abstract: Introduction: The purpose of this study was to research the presence of filamentous fungi in the root canals of teeth with pulp necrosis and periapical lesions and to perform the taxonomic study of the isolates. Methods: Samples collected from 60 root canals with sterile absorbent paper points were inoculated in Sabouraud dextrose agar supplemented with chloramphenicol. The material was cultured from 7–14 days at room temperature to observe mycelial growth. Samples with growth were seeded in media specific for microculture (CYA agar, malt extract agar, or potato dextrose agar). Taxonomy was evaluated by macroscopic examination and optical microscopy. Results: Filamentous fungi were isolated in situ from 17 of 60 samples (28.3%). Considering the positive root canal isolates, the genus Aspergillus was isolated from 7 samples (41%); 4 species were identified: Aspergillus ustus, A. granulosus, A. niger, and A. sydowii. Emericella quadriluniata, sexual form of Aspergillus, was isolated from 1 sample. Penicillium species (Penicillium implicatum, P. micsynvisk, P. lividum, and P. citrionigrum) were isolated from 4 samples (24%). Fusarium species (Fusarium moniliforme and F. melanochorum) were isolated from 2 samples (12%). The species Aureobasidium pullulans, Exophiala jeanselmei, Eurotium amstelodame, and Cladosporium sphaerospermum were isolated from 1 sample each. Conclusions: The root canals of teeth with pulp necrosis and periapical lesions might present positive culture for filamentous fungi. [Copyright &y& Elsevier]

Introduction: Third molar morphology is very complex due to the variety of shapes and also to the number of roots and canals, which makes its treatment a real challenge and trial for the practitioner. Objectives: This study aims to analysing the internal radicular morphology of three molars, using a contrastive substance injected on the channel and the technique of teeth transparency. Materials and method: 38 teeth extracted on various reasons were studied after removing the dental pulp. An intracanalicular injection of a contrast substance (China ink) followed. The teeth were decalcified using nitric acid and were subsequently made transparent by using methil salicilate in order to point out aspects of internal radicular anatomy. Results: Third maxillary molars presented Ventucci types II and IV canals for mesio-vestibulary root, Ventucci I type canals for disto-vestibular and palatal roots. Intercanalicular communication was frequntly found at the level of the mesio root and lateral canals were found especially in the apical third. Conclusions: Knowledge of internal radicular morphology considerably improves the therapeutic vision leading to the suceess of endodontic treatment. [ABSTRACT FROM AUTHOR]

The purpose of this study was to demonstrate the importance of knowledge of the internal anatomy of root canals for the success of endodontic treatment. Lack of knowledge of anatomic variations and their characteristics in different teeth has been pointed out as one of the main causes of endodontic therapy failure. In this report, the authors describe the endodontic treatment of a mandibular first molar with five root canals, evaluate the rate of occurrence of this number of canals, and discuss the importance of their identification and treatment. [ABSTRACT FROM AUTHOR]

Abstract: We investigated the photodynamic effects of methylene blue on multispecies root canal biofilms comprising Actinomyces israelii, Fusobacterium nucleatum subspecies nucleatum, Porphyromonas gingivalis, and Prevotella intermedia in experimentally infected root canals of extracted human teeth in vitro. The 4 test microorganisms were detected in root canals by using DNA probes. Scanning electron microscopy showed the presence of biofilms in root canals before therapy. Root canal systems were incubated with methylene blue (25 μg/mL) for 10 minutes followed by exposure to red light at 665 nm with an energy fluence of 30 J/cm2. Light was delivered from a diode laser via a 250-μm diameter polymethyl methacrylate optical fiber that uniformly distributed light over 360 degrees. Photodynamic therapy (PDT) achieved up to 80% reduction of colony-forming unit counts. We concluded that PDT can be an effective adjunct to standard endodontic antimicrobial treatment when the PDT parameters are optimized. [Copyright &y& Elsevier]

Background: This case report describes the healing of a large periradicular lesion involving an adjacent implant. Endodontic surgery was performed in combination with placement of an enamel matrix protein derivative. Methods: Endodontic surgery was performed, including root end resection at a 90c angle. Ultrasonic tips were used for retrograde preparation, and the retrograde cavity was sealed with zinc oxide-eugenol. The area was filled carefully with enamel matrix proteins. Sutures were removed after a 2-week healing period. Results: There were no symptoms of pain, inflammation, or discomfort at 18 months post-surgery. Radiographs showed complete healing of the periradicular lesion. Conclusions: Combining an enamel matrix protein derivative with conventional surgery may improve the clinical outcome of large endodontic lesions. Additional research is warranted. [ABSTRACT FROM AUTHOR]

Abstract: Enterococcus faecalis can survive for extended periods in obturated root canals. In this study, the hypotheses tested were that long-term survival of E. faecalis is dependent on (1) the type of endodontic sealer and (2) the capacity for microbial gelatinase activity, a potential “virulence” trait identified previously in clinical isolates. Root canals of extracted human canines (n = 95) were inoculated with either E. faecalis OG1RF or its gelatinase-negative mutant E. faecalis TX5128. After 48 hours of incubation at 37°C, canals were obturated with gutta-percha and either the epoxy-resin-based AH-Plus (Dentsply, De Trey, Konstanz, Germany), the silicone-based RoekoSeal (Coltène/Whaledent, Langenau, Germany), or zinc oxide eugenol-based Roth’s sealer (Root Canal Cement Type 801; Roth International Ltd, Chicago, IL). Access cavities were sealed. After 8 months of incubation at 37°C, viable E. faecalis was recovered from more teeth sealed with RoekoSeal (95%) compared with AH-Plus (40%) (p = 0.0004, Fisher’s exact test) and Roth’s sealer (45%) (p = 0.0012, Fisher’s exact test). In the RoekoSeal groups, viable counts of E. faecalis OG1RF were higher than E. faecalis TX5128 (p = 0.03, Mann-Whitney U test) suggesting that gelatinase activity plays a role in long-term survival of E. faecalis in obturated root canals. [Copyright &y& Elsevier]

Aim. To compare in vitro the cleanliness of root canal walls following the use of two automated instrumentation techniques. Methodology. Thirty extracted human maxillary central incisors, maxillary and mandibular canines and premolars with single root canals were examined in this study. The teeth were divided into two groups. In group 1 (20 teeth), automated canal preparation was performed using Anatomic Endodontic Technology (AET). In group 2 (10 teeth), root canals were prepared with ProTaper nickel titanium (NiTi) rotary instruments. Irrigation was performed using alternately 3.00% NaOCl and 18% EDTA, followed by rinsing with saline. The roots were split longitudinally into halves and the canals examined using a scanning electron microscope. The presence of a debris and smear layer was recorded at the coronal, middle and apical thirds of root canals using a fourstep scoring scale. Mean scores for debris and smear layers were calculated and statistically analysed for significance (p < 0.05) between and within the groups, using the Mann--Whitney--Wilcoxon and Friedman nonparametric tests. Results. Under the conditions of this study, the removal of superficial debris and smear layers was generally good with both canal preparation techniques. However, both techniques resulted in variable presence of residual superficial debris and smear layers. Statistical analysis showed that there was no significant difference between the experimental groups in all thirds of root canals for a superficial debris and smear layer (p > 0.05). Comparison of the removal of the smear layer among the three regions showed that in AET group there was a statistically significant difference among all parts, especially between the middle and apical thirds (p < 0.005). Overall, the middle sections were cleaner than the coronal and apical ones. Conclusions. Complete cleanliness was not achieved by any of the techniques and instruments investigated. It may be inferred that the choice between AET and ProTaper instrumentation should be based on factors other than the amount of root canal debridement, which does not vary high significantly according to the instruments used. [ABSTRACT FROM AUTHOR]

Abstract: The aims of this study were to investigate the effects of photodynamic therapy (PDT) on endodontic pathogens in planktonic phase as well as on Enterococcus faecalis biofilms in experimentally infected root canals of extracted teeth. Strains of microorganisms were sensitized with methylene blue (25 μg/ml) for 5 minutes followed by exposure to red light of 665 nm with an energy fluence of 30 J/cm2. Methylene blue fully eliminated all bacterial species with the exception of E. faecalis (53% killing). The same concentration of methylene blue in combination with red light (222 J/cm2) was able to eliminate 97% of E. faecalis biofilm bacteria in root canals using an optical fiber with multiple cylindrical diffusers that uniformly distributed light at 360 degrees. We conclude that PDT may be developed as an adjunctive procedure to kill residual bacteria in the root canal system after standard endodontic treatment. [Copyright &y& Elsevier]

AbstractAimThe aim of this in vitro study was to evaluate the antimicrobial effectiveness of electro-chemically activated water (ECA) as an endodontic irrigation solution. MethodologyThe root canals of 60 caries-free, single-rooted, adult, maxillary, anterior human teeth were instrumented and irrigated in a similar method to that used for in vivo root canal treatment. The external root surface of each tooth was sealed, maintaining the access cavities patent and the root canals were inoculated with a suspension containing four bacteria. The teeth were randomly divided into four groups (n = 15). Each group was irrigated ultrasonically with one of the following solutions: distilled water (control), NaOCl (3.5%), and ECA, the latter at pHs 7.0 and 9.0. Antimicrobial effectiveness was established directly after irrigation and again 7 days later, by counting colony-forming units on blood agar plates and by spectrophotometric analysis. ResultsLarge numbers of bacteria were present in the canals of teeth irrigated with distilled water. No bacteria were observed following irrigation with NaOCl. Neither of the ECA solutions were found to be effective against all the bacteria. Although some reduction in the number of bacteria was evident in the ECA groups, this was not statistically significant (P > 0.05) when compared to sodium hypochlorite. ConclusionWithin the confines of this study ECA did not demonstrate antimicrobial effectiveness. [ABSTRACT FROM AUTHOR]

AbstractThompson SA. An overview of nickel–titanium alloys used in dentistry. International Endodontic Journal, 33, 297–310, 2000. Literature review The nickel–titanium alloy Nitinol has been used in the manufacture of endodontic instruments in recent years. Nitinol alloys have greater strength and a lower modulus of elasticity compared with stainless steel alloys. The super-elastic behaviour of Nitinol wires means that on unloading they return to their original shape following deformation. These properties are of interest in endodontology as they allow construction of root canal instruments that utilize these favourable characteristics to provide an advantage when preparing curved canals. This review aims to provide an overview of Nitinol alloys used in dentistry in order for its unique characteristics to be appreciated. [ABSTRACT FROM AUTHOR]

AbstractAim To determine the general efficacy and shaping ability of Hero 642 nickel–titanium rotary instruments during the preparation of simulated canals. Part 1 of this two-part report describes the efficacy of the instruments in terms of three-dimensional canal form. Methodology A total of 40 simulated root canals made up of four different shapes in terms of angle and position of curvature were prepared by Hero 642 instruments using a crown-down preparation sequence. The efficacy of the instruments was assessed in terms of preparation time, instrument failure, canal blockages and loss of canal length. Intra-canal impressions were taken of the prepared canals in order to assess three-dimensional canal form. Results The mean time for canal preparation was 8.6 min and was influenced significantly (P < 0.05) by canal shape. Two instruments fractured and eight instruments deformed; significant differences were observed between canal shapes (P < 0.05). All of the canals remained patent. Fifteen canals (39.5%) maintained the correct working distance, 15 lost distance and eight canals gained length. Examination of intracanal impressions demonstrated that the majority of canals (79%) had apical stops; canal shape had a significant influence (P < 0.001) on the quality of apical stops. With one exception all canals had smooth canal walls and all of the canals showed good flow characteristics. Taper was poor in 30 canals (79%) and good in eight canals (21%). Conclusions Hero 642 rotary nickel–titanium instruments prepared simulated canals rapidly but with a three-dimensional form that lacked adequate taper. [ABSTRACT FROM AUTHOR]

AbstractAim To determine the shaping ability of Hero 642 nickel–titanium rotary instruments during the preparation of simulated canals. Methodology A total of 40 simulated root canals made up of four different shapes, in terms of angle and position of curvature, were prepared by Hero 642 instruments using a crown-down preparation sequence. Pre- and postoperative images of the canals were taken using a video camera attached to a computer with image analysis software. The pre- and postoperative views were superimposed to highlight the amount and position of material removed during preparation. This report describes the efficacy of the instruments in terms of prevalence of canal aberrations, the amount and direction of canal transportation and overall postoperative shape. Results Four zips and four elbows were created during preparation, all in canals with 40°, 12 mm curves. No perforations or danger zones were created. Highly significant differences (P < 0.001) were apparent between the canal shapes in total canal width at the apex and beginning of the curve, and in the amount of resin removed from the inner and outer aspects of the curve at the orifice. Canal transportation was most frequently directed toward the outer aspect of the curve at specific points along the canal, except at the orifice, where it was apparent that canals with 20° curves transported toward the inner. Overall, mean absolute transportation was always less than 0.15 mm; however, significant differences occurred between canal shapes at the end-point (P < 0.01), apex of the curve (P < 0.01) and at the orifice (P < 0.01). ConclusionsUnder the conditions of this study, Hero 642 rotary nickel–titanium instruments created canals with few aberrations and no perforations. The relatively high proportion of aberrations in canals with short, acute curves may indicate that instruments with increased taper should be used with caution at or near the full working distance. Further... [ABSTRACT FROM AUTHOR]

AbstractAim The aim of this investigation was to assess canal cleaning following shaping with hand files of greater taper. Methodology Thirty mesial canals and 30 distal canals in mandibular molars were prepared with .08 and .10 hand files of greater taper, respectively. Following initial preparation, 0.02 instruments were used incrementally shorter in a stepback manner. In half the canals instrumentation was performed to size 35 1 mm short of the canal terminus. In the other half the series was continued through to size 60 using stepback increments of half to one millimetre as appropriate (foramen size was maintained at size 20 in all groups). Sodium hypochlorite (4.5%) and REDTA (17%) were used as irrigants for all groups. Cleaning efficacy was evaluated by scoring the amount of remaining debris using a light microscope (×50) and calibrated eyepiece micrometer (range 0–3). Results Canals stepped back through to a size 60 were significantly cleaner than those instrumented to a size 35 only (Mann–Whitney P < 0.05). ConclusionRefining the apical region of canal preparation by stepping back through to a size 60 reduced remaining debris following shaping with files of greater taper. [ABSTRACT FROM AUTHOR]

Aim The aim of this study was to determine the shaping ability of ProFile .04 and .06 taper rotary nickel–titanium instruments in simulated canals. Methodology A total of 40 simulated root canals made up of four different shapes in terms of angle and position of curvature were prepared using the ‘crown-down’ approach recommended by the manufacturer. Pre-operative pictures of each canal were recorded on optical discs using an image analysis package. The simulated canals were prepared and postoperative pictures superimposed on the original images. Results No instrument fractures occurred and none deformed; none of the canals became blocked with debris. Change in working distance was, on average, 0.063 mm with 33 canals retaining the correct length. Overall, five zips (12.5%) were created and 24 (60%) canals demonstrated a widened area on the outer aspect of the canal between the end-point and the curve. Two danger zones (5%) were created and two perforations but no ledges were found. Between canalshapes there were highly significant differences (P 0.0001) for the incidence of zips and elbows but not for the other aberrations. There were highly significant differences (P 0.0001) for the total width of the canals between the various canal shapes at the apex of the curve, the beginning of the curve and half way to the orifice, and a significant difference (P 0.05) at the end-point. There were highly significant differences (P 0.0001) for the amount of resin removed from the outer aspect of the curve at the end-point and at the beginning of the curve, and significant differences (P 0.05) at the apex of the curve and half way to the orifice. There were highly significant differences (P 0.0001) for the amount of resin removed from the inner aspect of the curve at the beginning of the curve and half way to the orifice. Overall, transportation was towards the outer aspect of the canal except at the beginning of the curve. Conclusions Under the... [ABSTRACT FROM AUTHOR]

The aim of this study was to determine the shaping ability of ProFile 0.04 taper rotary nickel-titanium instruments with ISO sized tips in simulated canals. A total of 40 simulated root canals made up of four different shapes in terms of angle and position of curvature were prepared by ProFile instruments using the ‘crown down’ approach recommended by the manufacturer. Part 2 of this two-part report describes the efficacy of the instruments in terms of prevalence of canal aberrations, the amount and direction of canal transportation and the overall post-operative shape. Out of 37 completed specimens 9 zips (24%) and one ledge (3%) were created, but no perforations or danger zones were found. There were significant differences (P < 0.01) between canal shapes for the incidence of zips and elbows but not for their distance from the end-point of preparation. At specific positions along the canal length there were significant differences between the canal types in terms of their mean total width; overall, at the end-point of preparation and along the curved portion of the canals those specimens with 40° curves were widest. This trend continued for the width of material removed from the outer aspect of the canal curves, whereas along the inner aspect of curves more material was removed in the 20° canals. Overall, transportation was towards the outer aspect of the curve at the end-point of preparation and along the curved portion of canals but more balanced along the straight coronal section. Absolute transportation was small and below 0.1 mm at every position including the zips. Under the conditions of this study, ProFile nickel-titanium rotary instruments with ISO sized tips produced a larger number of zips than expected; however, the degree of zipping was limited and relatively minor. [ABSTRACT FROM AUTHOR]

The aim of this study was to determine the shaping ability of Quantec Series 2000 nickel-titanium instruments in simulated canals. A total of 40 simulated root canals made up of four different shapes in terms of angle and position of curvature were prepared by Quantec instruments using the technique recommended by the manufacturer. Part 1 of this two-part report describes the efficacy of the instruments in terms of preparation time, instrument failure, canal blockages, change in canal length and three-dimensional canal form. The time necessary for canal preparation was on average 5.7 min and was significantly influenced (P < 0.01) by canal shape. One instrument fractured and three size nine instruments deformed; however, canal shape did not influence significantly instrument failure. All of the canals remained patent, none became blocked with debris. The majority of the canals maintained working distance (26 out of 40), however the mean change in length differed significantly (P < 0.05) between canal types. Overall, canals with 40° curves lost length whilst those with 20° curves gained in length. Examination of intracanal impressions revealed that preparation with Quantec Series 2000 instruments produced canals with definite apical stops, smooth canal walls and good flow and taper. However, the quality of apical smoothness and flow was influenced significantly (P < 0.0001) by canal shape with specimens having 40° canals displaying less desirable qualities. Under the conditions of this study, Quantec Series 2000 rotary nickel-titanium instruments prepared simulated canals rapidly, safely and with good three-dimensional form. [ABSTRACT FROM AUTHOR]

The aim of this laboratory based study was to determine the shaping ability of Quantec Series 2000 nickel-titanium rotary instruments in simulated root canals. A total of 40 canals with four different shapes in terms of angle and position of curve were prepared with Quantec Series 2000 instruments using the technique recommended by the manufacturer. Part 2 of this report describes the efficacy of the instruments in terms of prevalence of canal aberrations, the amount and direction of canal transportation and overall post-operative shape. Pre- and post-operative images of the canals were taken using a video camera attached to a computer with image analysis software. The pre- and post-operative views were superimposed to highlight the amount and position of material removed during preparation. Twenty-one zips and elbows were created during preparation with a significant difference (P < 0.005) between canal shapes in terms of the incidence of aberrations. Four perforations were created, with significant differences (P < 0.005) between the canal shapes; three ledges were also created but no danger zones. Highly significant differences (P < 0.001) were apparent between the canal shapes in total canal width at specific points along the canal length and in the amount of resin removed from the inner and outer aspects of the curve. Canal transportation at the end-point of preparation was most frequently directed towards the outer aspect of the curve, and without exception in canals with 40° curves. At the beginning of the curve, transportation became more evenly balanced between the inner and outer aspect of the curve, although predominated towards the outer. Transportation was generally directed towards the outer at the orifice, especially in canals with 40° curves. Mean absolute transportation at the various measurement points was less than 0.11 mm; significant differences occurred between canal shapes at the end-point of preparation (P < 0.0001), at the zips (P < 0.005), at the apex (P < 0.0001) and beginning of the curve (P < 0.05) and at the orifice (P < 0.0001). Under the conditions of this study, Quantec Series 2000 rotary nickel-titanium instruments created a relatively large number of aberrations including four perforations. The aberrations were created by the larger instruments implying that these should be used with caution at the full working distance. Scanning electron micrographs of these instruments revealed sharp instrument tips which appeared likely to predispose to transportation and the creation of defects along the outer aspect of severely curved canals. [ABSTRACT FROM AUTHOR]

The aim of this study was to determine the shaping ability of ProFile 0.04 taper rotary nickel-titanium instruments with ISO sized tips in simulated canals. A total of 40 simulated root canals made up of four different shapes in terms of angle and position of curvature were prepared by ProFile instruments using the ‘crown down’ approach recommended by the manufacturer. Part 1 of this two-part report describes the efficacy of the instruments in terms of preparation time, instrument failure, canal blockages, loss of canal length and three-dimensional canal form. The time necessary for canal preparation was on average 5.2 min and was not influenced significantly by canal shape. Three instrument fractures occurred and a further 3 instruments deformed; size 35 instruments failed the most (4) followed by size 30 (2), four of the failures occurred in canals with 40° curves. None of the canals became blocked with debris and change in working distance was minimal. Intra-canal impressions of canal form demonstrated that most canals had apical stops and smooth canal walls whereas all canals had good flow and taper. Under the conditions of this study, ProFile 0.04 taper rotary nickel-titanium instruments with ISO sized tips prepared simulated canals rapidly and created good three-dimensional form. [ABSTRACT FROM AUTHOR]

The aim of this study was to determine the shaping ability of ProFile.04 Taper Series 29 nickel-titanium instruments in simulated canals. A total of 40 simulated root canals made up of four different shapes in terms of angle and position of curvature were prepared by ProFile instruments using a step-down approach. Part 1 of this two-part report describes the efficacy of the instruments in terms of preparation time, instrument failure, canal blockages, loss of canal length and three-dimensional canal form. The time necessary for canal preparation was not influenced significantly by canal shape. No instrument fractures occurred but a total of 52 instruments deformed. Size 6 instruments deformed the most followed by sizes 5, 3 and 4. Canal shape did not influence significantly instrument deformation. None of the canals became blocked with debris, and loss of working distance was on average 0.5 mm or less. Intra-canal impressions of canal form demonstrated that most canals had definite apical stops, smooth canal walls and good flow and taper. Under the conditions of this study, ProFile.04 Taper Series 29 rotary nickel-titanium instruments prepared simulated canals rapidly and created good three-dimensional form. A substantial number of instruments deformed but it was not possible to determine whether this phenomenon occurred because of the nature of the experimental model or through an inherent design weakness in the instruments. [ABSTRACT FROM AUTHOR]

The aim of this laboratory-based study was to determine the shaping ability of NT Engine and McXim nickel-titanium rotary instruments in simulated root canals. A total of 40 canals with four different shapes in terms of angle and position of curve were prepared with NT Engine and McXim instruments, using the technique recommended by the manufacturer. Part 2 of this report describes the efficacy of the instruments in terms of prevalence of canal aberrations, the amount and direction of canal transportation and overall postoperative shape. Pre-and postoperative images of the canals were taken using a video camera attached to a computer with image analysis software. The pre- and postoperative views were superimposed to highlight the amount and position of material removed during preparation. No zips, elbows, perforations or danger tones were created during preparation. Forty-two per cent of canals had ledges on the outer aspect of the curve, the majority of which (16 out of 17) occurred in canals with short acute curves. There were significant differences (P<0.001) between canal shapes in terms of the incidence of ledges. There were highly significant differences (P<0.001) between the canal shapes in total canal width at specific points along the canal length and in the amount of resin removed from the inner and outer aspects of the curve. The direction of canal transportation at the end- point of preparation was most frequently towards the outer aspect of the curve, especially in canals with 40° curves. At the beginning of the curve, transportation in the majority of canals was towards the inner aspect of the curve. Mean absolute transportation was less than 0.03 mm throughout the curve and towards the end- point, with significant differences between canal shapes occurring at the apex (P<0.05) and at the beginning of the curve (P<0.001). Under the conditions of this study, NT Engine and McXlm rotary nickel-titanium instruments created no aberrations other than ledges and produced only minimal transportation. The overall shape of canals was good. [ABSTRACT FROM AUTHOR]