Apical transportation and centering ability: A comparison of two single-file systems after instrumentation to the major foramen and after overinstrumentation in curved root canals

This study was conducted to compare apical transportation and centering ability to the major foramen after instrumentation and overinstrumentation with M-wire Reciproc® 25 and WaveOne® primary in severely curved canals of extracted teeth. Thirty mesiobuccal root canals of extracted mandibular and maxillary molars,with a major foramen width less than size 20 and angles of curvatures between 20º and 40º, were prepared with M-wire Reciproc® 25 or WaveOne® primary to the foramen and 1 mm beyond the foramen. Digital images of the apical foramen before and after instrumentation and overinstrumentation were taken with a digitalcamera (Olympus, E330, DC 7.4V) coupled with a stereomicroscope (Olympus, CX41, E330, Japan). Each image taken after the instrumentation of the foramen was superimposed on the preliminary image using a CS3 extended Adobe Photoshop program (San Jose, CA, USA). Apical transportation and centering ability were calculated using an AutoCAD program (Autodesk, Software, USA) in the direction of maximum curvature. Repeated measured analyses of variance followed by univariate analyses were conducted. No significant difference was observed after the use of M-wire Reciproc ® 25 or WaveOne® primary to the working length (p \u3e 0.05). The M-wire Reciproc® 25 had a higher mean value for transportation and a lower mean value for centering ability (p \u3c 0.05) than the WaveOne® primary when they were used 1 mm beyond the foramen. M-wire Reciproc® 25 and WaveOne® primary were safe to use to the foramen. After overinstrumentation, M-wire Reciproc® 25 produced higher transportation of the major foramen than WaveOne® primary

Taper Preparation Variability Compared to Current Taper Standards Using Computed Tomography

Introduction. The purpose of this study was to compare the taper variation in root canal preparations among Twisted Files and PathFiles-ProTaper .08 tapered rotary files to current standards. Methods. 60 root canals with severe angle of curvature (between 25° and 35°) and short radius (r < 10 mm) were selected. The canals were divided randomly into two groups of 30 each. After preparation with Twisted Files and PathFiles-ProTaper to size 25 taper .08, the diameter was measured using computed tomography (CT) at 1, 3, and 16 mm. Canal taper preparation was calculated at the apical third and at the middle-cervical third. Results. Of the 2 file systems, both fell within the ±.05 taper variability. All preparations demonstrated variability when compared to the nominal taper .08. In the apical third, mean taper was significantly different between TF and PathFiles-ProTaper (P value < 0.0001; independent t-test). Mean Taper was significantly higher with PathFile-ProTaper. In the middle-cervical third, mean Taper was significantly higher with TF (P value = 0.015; independent t-test). Conclusion. Taper preparations of the investigated size 25 taper .08 were favorable but different from the nominal taper

Root and Root Canal Morphology of Premolars in a Sample of the Lebanese Population: Clinical Considerations

ABSTRACT Objectives: The aim of this study was to investigate the anatomy of the maxillary and mandibular premolars among a sample of the Lebanese population and to explore their incidence by sex and the symmetry between the left and right sides. Materials and Methods: This retrospective analysis of 250 cone-beam computed tomography (CBCT) scans consisted of 960 maxillary and 972 mandibular premolars. Roots, canals, and morphology types were recorded. Vertucci’s classification was used to categorize the canal morphologies. Fisher’s exact and chi-square tests (P≤.05) were applied. Results: The majority of maxillary first premolars had two roots (85.3%) with two canals (91.3%). Most of the maxillary second premolars showed one root (79.8%). Two-root canals (53.55%) were more common than one canal (44.2%). The three-root, three-canal morphology was rarely spotted in the maxillary first (0.4%) and second premolars (2.3%). The one-root (99.2%) and one-canal (84.5%) morphologies were most frequently located in the mandibular first and second premolars (100%, 88.6%), and two canals being less common (15.5%, 11.4%) correct same as before. The total prevalence of premolars with a complex root canal morphology was 62.4%, found in types II, III, and V to VIII. Men had significantly more roots and root canals in their maxillary first premolars than women (P≤.05). No significant differences were observed between the contralateral premolars (P\u3e.05). Conclusions: Premolars displayed wide variations in root and root canal morphology and symmetry between the contralateral premolars. Keywords: cone-beam computed tomography (CBCT), mandibular premolars, maxillary premolars, root canal anatomy, root canal configuration, sex distribution, symmetry. Objectif Cette étude vise à examiner le nombre de racines, les canaux radiculaires et la morphologie des canaux des prémolaires maxillaires et mandibulaires, au sein d’une population libanaise. Matériels et méthodes 250 images CBCT de 960 prémolaires maxillaires et 972 prémolaires mandibulaires ont été analysées rétrospectivement. Les tests de Fisher Exact et du Chi-Carré (P \u3c 0,05) ont été appliqués pour évaluer le nombre de racines et de canaux radiculaires, la fréquence et la symétrie entre les côtés gauche et droit, ainsi que l’incidence au sein du sexe. La classification de Vertucci a été utilisée pour classer les morphologies des canaux. Résultats Les premières prémolaires maxillaires étaient principalement caractérisées par deux racines (1 racine : 14,4%, 2 racines: 85,3% et 3 racines: 0,4%), avec deux canaux (91,3%). Une racine a été observée dans de nombreuses deuxièmes prémolaires maxillaires (79,8 %). Cependant, deux canaux radiculaires (53,55 %) étaient plus fréquents qu’un canal (44,2 %). Trois racines et trois canaux ont rarement été repérés dans les premières (0,4 %, 0,4 %) et les deuxièmes prémolaires maxillaires (2,3 %, 2,3 %). Une racine avec un canal était localisée respectivement le plus fréquemment dans la première (99,2 %, 84,5 %) et la deuxième prémolaire mandibulaire (100 %, 88,6 %), bien que deux canaux soient moins fréquents (15,5 %, 11,4 %). Des prémolaires avec une anatomie complexe du canal radiculaire ont été trouvées avec une prévalence de 16,2% allant du type II, III et de V à VIII. Les résultats ont également montré des différences entre les sexes : les hommes avaient remarquablement plus de racines et de canaux radiculaires dans leurs premières prémolaires maxillaires que les femmes (P \u3c 0,05). Aucune différence statistique n’a été observée entre les paires prémolaires controlatérales (P ³ .5). Conclusion Au sein de cette sous-population libanaise, les prémolaires maxillaires et mandibulaires présentaient de grandes variations dans la morphologie des racines et des canaux radiculaires, et une symétrie entre les paires controlatérales. Ces résultats susciteraient un intérêt clinique pour les praticiens et les chercheurs. Mots-clés : CBCT, prémolaires mandibulaires, prémolaires maxillaires, anatomie canalaire, configuration canalaire, symétrie, sexe

L’influence de la technique de pose sur l\u27adaptation marginale du MTA : étude comparative in vitro

Teeth with open apices require a particular approach, which is to create an apical barrier and to hermetically seal large foramina. The objective of this study was to compare, in vitro, the apical seal obtained with MTA after its introduction into the canal with two different techniques. For this purpose, 102 maxillary and mandibular extracted teeth were selected. Root canals were shaped and randomly divided into two groups (n= 50 per group). The last five millimeters (mm) were filled with white MTA by two different techniques: MTA powder mixed with distilled water and MTA powder and distilled water introduced separately. The two “negative control” teeth (1 tooth in each group) were covered with two layers of varnish, including the apical foramen. The last 6 mm of all samples were immersed in 2% methylene blue dye for 7 days. The dye-penetration was detected by performing horizontal cuts that have been examined with a light microscope (×20). Statistical analysis performed with independent t-test and Fisher exact test showed a significant difference between the two techniques

Comparaison in vitro de trois systèmes d’irrigation : EndoVac, RinsEndo et Seringue pour l’élimination des débris intracanalaires

The anatomical complexity of the canal system tends to reduce the tissue-dissolving capacity and antibacterial effect of sodium hypochlorite especially in the apical zone of the root canal. Several means of irrigation were used during the last decade. Among the three systems tested in this study, RinsEndo showed the most satisfactory results as for the elimination of the dentinal debris on the apical third

Étude histologique in vivo de la réaction du tissu pulpaire après coiffage pulpaire direct avec le ciment de portland modifié

Capping an exposed pulp in order to maintain the vitality of the pulp is the main purpose of pulp capping procedure. The success of this procedure depends on the capacity of pulp capping agent to stimulate pulp tissue repair and dentin bridge formation. Mineral Trioxide Aggregate (MTA) is a biocompatible agent that allows growth, proliferation and differentiation of mesenchymal cells in the pulp. Despite its many advantages, the handling of the MTA and its long setting time (4 hours) oblige the clinician to postpone the restoration to another day. A new product, called CPM (ciment de Portland modifié), has been lately in use. It has the same characteristics of the MTA added to an easier handling way and a shorter setting time. The aim of this study is to compare histologically the reaction of the pulp tissue after a direct pulp capping of rat molars, using the CPM or the MTA

The Influence of Brushing Motion on the Cutting Behavior of 3 Reciprocating Files in Oval-shaped Canals

International audienceIntroduction: The purpose of this study was to compare the cutting efficiency of 3 reciprocating single-file systems used with a brushing motion in oval-shaped canals. Methods: Sixty premolars with single oval canals were selected and randomly assigned to 3 groups according to the file used in canal instrumentation: R25 Reciproc (VDW, Munich, Germany), Primary WaveOne ((Dentsply Maillefer, Ballaigues, Switzerland), and a novel prototype instrument (UFile; MicoMega, Besancon, France). Instru-mentation was performed in 4 consecutive steps; according to manufacturers' instructions, 5 brushing strokes against the buccal wall with a nonworking instrument followed by another 5 and 15 brushing strokes with a working file. Cone-beam computed tomographic scans were taken after each step of preparation. Pre-and postinstru-mentation images were superimposed at the apical and midroot levels and then evaluated in terms of changes in the maximum buccolingual (DBL) and mesiodistal dimensions (DMD). Results: Instrumentation with a brushing motion resulted in the following findings. At the apical levels, no significant difference was found in DBL for the 3 groups (P > .05). However, DMD was significantly less for the Reciproc (P = .006) and UFile (P = .03) groups. At the midroot levels, the UFile group showed the highest significance in terms of DBL (P < .0001) but the lowest in terms of DMD (P = .003). DMD was significantly the highest for the WaveOne group at the midroot levels (P = .05). Conclusions: The prototype file was more efficient than the other files at the midroot levels, whereas all systems acted the same at the apical levels. The increase in the number of brushing strokes resulted in more dentinal cutting in the direction of those strokes. (J Endod 2015;-:1–7

Quantitative volumetric analysis of cross-linked gutta-percha obturators

Aim The purpose of this study was to evaluate the effects of technique on the filling quality of 2 recently introduced obturation systems comparatively with warm vertical compaction using micro-computed tomography. Methods 36 single-rooted teeth were selected, root canals prepared, and assigned to 3 groups (n=12), according to the filling technique: warm vertical compaction technique WVC, GuttaCore (Dentsply Tulsa Dental Specialties, Tulsa, OK) and Gutta Fusion (VDW, Germany). Each specimen was scanned using a micro-CT. Percentage of voids was calculated and data statistically analyzed using Kruskal Wallis test with a significance level of 5%. Results All obturations showed satisfactory similar results at the apical level. Differences between the three obturation methods were not significant at 1 mm (−p-value >0.05), 3 mm (−p-value >0.05) and 5 mm (−p-value >0.05). No root fillings were void-free. No significant difference was found between the WVC technique, the GuttaCore technique and the Gutta Fusion technique concerning percentage of apical voids regardless of canal level. Conclusion This study shows the efficiency of cross-linked obturators in filling root canals hermetically by comparing them to the warm vertical compaction technique. Results show that these obturation techniques were equally sufficient concerning apical adaptation making them appropriate to use in endodontic obturations

Impact of Warm Vertical Compaction on the Sealing Ability of Calcium Silicate-Based Sealers: A Confocal Microscopic Evaluation

The aim of this in vitro study was to evaluate the dentinal tubule penetration of two calcium silicate-based sealers used in warm vertical compaction (WVC) obturation technique in comparison with the single cone (SC) technique by confocal laser scanning microscopy (CLSM). The null hypothesis was that both obturation techniques produced similar sealer penetration depths at 1 and 5 mm from the apex. Forty-four mandibular single-rooted premolars were randomly divided into four equally experimental groups (n = 10) and two control groups (n = 2) according to the type of sealer (Bio-C Angelus, Londr&iacute;na, PR, Brazil or HiFlow Brasseler, Savannah, GA, USA) with either SC or WVC. The sealers were mixed with a fluorescent dye Rhodamine B (0.1%) to enable the assessment under the CLSM. All the specimens were sectioned horizontally at 1 and 5 mm from the apex. The maximum penetration depth was calculated using the ImageJ Software (ImageJ, NIH). Data were analyzed by Mann&ndash;Whitney U and Kruskal&ndash;Wallis tests (p &lt; 0.05). A significant difference was shown between the four groups at 1 mm (p = 0.0116), whereas similar results were observed at 5 mm (p = 0.20). WVC allowed better diffusion for both sealers at 1 mm (p = 0.01) and 5 mm (p = 0.034). The maximum penetration of the Bio-C and HiFlow sealers was more important at 5 mm with the two obturation techniques. Within the limitations of this study, WVC enhanced the penetration of calcium silicate-based sealers into the dentinal tubules in comparison with the SC technique at both levels

Influence of the Maxillary Sinus on the Accuracy of the Root ZX Apex Locator: An Ex Vivo Study

This study evaluated the accuracy of the Root ZX (J. Morita, Tokyo, Japan) electronic apex locator in determining the working length when palatal maxillary molar roots are in a relationship with the sinus. Seventeen human maxillary molars with vital pulp were scheduled for an extraction and implant placement as part of a periodontal treatment plan. The access cavity was prepared, and a #10 K file (Dentsply Maillefer, Ballaigues, Switzerland) was inserted into the palatal root using the Root ZX apex locator in order to determine the electronic working length (EWL); then, the teeth were extracted. To determine the real working length (RWL), a #10 K file was introduced into the root canal until its tip touched a glass plate. EWL and RWL were compared. Images reconstructed with CBCT (cone beam computerized tomography) revealed that eight palatal roots were related to the maxillary sinus, whereas nine were not. The results showed a significant difference between the EWL and the RWL of the palatal roots related to the sinus (p &lt; 0.001). No significant difference was observed in measurements of roots not in contact with the sinus (p &gt; 0.05). Within the study limitations, the reliability of Root ZX was influenced by the relationship of the roots with the maxillary sinus