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To evaluate the influence of different heat treatments and temperatures on the cyclic fatigue resistance of 2Shape instruments (Micro Mega, Besancon, France) with the same design.A total of 80 2Shape TS1 (#25/.04) and 80 TS2 (#25/.06) files with different heat treatments (no heat-treated, NHT; C-Wire; T-Wire; CM-Wire) were tested at room (25° ± 1 °C) and body (37° ± 1 °C) temperatures in 16-mm stainless steel artificial canal with a curvature of 60° and 5 mm of radius. Files were tested in continuous rotation at 300 rpm using a customized device. Cyclic fatigue resistance was expressed in the number of cyclic to fracture (NCF). The phase transformation temperature of each file was determined by differential scanning calorimetry. Data were statistically analyzed using the two-way ANOVA and the Bonferroni post-hoc test with p 0.05.All CM-Wire TS1 and TS2 files showed higher NCF than the other groups at both temperatures (p 0.001). C-Wire TS2 showed higher resistance than NHT and T-Wire TS2 (p 0.001), with no significant differences between the last two. Body temperature significantly decreased NCF of all tested files (p 0.05) except for NHT and T-Wire TS1.Body temperature negatively affected the cyclic fatigue resistance of C-Wire and CM-Wire TS1 and of all TS2 files compared with room temperature. The CM-Wire instruments exhibited the highest cyclic fatigue resistance of all tested files.Heat-treated nickel-titanium files can differently perform according to environmental temperature and file dimensions. The CM-Wire 2Shape prototypes displayed the highest flexural resistance in all experimental conditions.

Objectives: The aims of this study were 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 CBCT images revealed 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 and one-canal morphologies were most frequently located in the mandibular first (99.2%, 84.5%) and second premolars (100%, 88.6%), and two canals being less common (15.5%, 11.4%). 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>.05).Conclusions: Premolars displayed wide variations in root and root canal morphology and symmetry between the contralateral premolars.Clinical Relevance: CBCT scans showed the morphological complexity and bilateral symmetry of the premolars in a sample of the Lebanese population. Clinicians and researchers should consider these findings.

Introduction The aim of this study was to evaluate under scanning electronic microscopy the enlargement and deformation of the apical foramen of curved mesiobuccal roots with both reciprocating and rotary single-file systems made of a newly heat-treated alloy through the use of Reciproc Blue (REC Blue; VDW, Munich, Germany) and XP-endo Shaper (XPS; FKG Dentaire, La Chaux-de-Fonds, Switzerland). Methods Forty mesiobuccal roots of mandibular and maxillary molars presenting a curvature ranging from 20°–40° were used in this study. The apical foramens were initially scanned with a scanning electronic microscope under 200× magnification. Roots were divided into 2 groups (n = 20): the REC Blue group instrumented with the REC Blue system and the XPS group instrumented with the XPS system. Both groups were instrumented at the foramen. The apical foramens were scanned after root canal preparation. The area, circularity, and ratio of the Feret diameters were calculated from each image. The Kolmogorov-Smirnov, Mann-Whitney, and Wilcoxon tests were used for statistical analysis (P ≤ .05). Results The area of the foramen increased significantly after canal shaping with REC Blue and XPS. The variation of the area was significantly greater with XPS. However, there were no significant differences in circularity and the ratio of the Feret diameters with both instruments. Conclusions No transportation was found when using REC Blue and XPS. The newly heat-treated nickel-titanium alloy did not promote deformation of the apical foramen in curved canals.

Aim To identify the prevalence of middle mesial canals (MMC) in mandibular molars in a Lebanese population to determine the relationship between MMC and different factors (age, sex, and tooth type) and to examine the canal's morphological aspects (category, length, orifice position, and dentin width toward furcation). Materials and methods The presence of MMC in the mesial roots of 505 mandibular molars of 200 patients was analyzed using cone-beam computed tomography (CBCT). Then, the position of the MMC orifices with respect to the pulpal floor and the main canals orifices, and the width of dentin along the canal toward the furcation were determined using 3D Slicer 4.10.1. Results In all, 14.65% of the first and second mandibular molars presented an MMC. A higher frequency of confluent canals was noted mostly joining the mesiobuccal canal (MBC). Gender appears to be a factor influencing the prevalence of MMCs, contrary to age-groups and tooth type. In mandibular first molars, the orifice is located at a mean distance of 1.22 ± 0.44 mm from the pulpal floor, 1.42 ± 0.53 mm from the MBC orifice, and 1.57 ± 0.60 mm from the mesiolingual canal (MLC) orifice. The width of dentin toward the furcation varies between 0.95 and 2.29 mm. In mandibular second molars, the orifice is located at a mean distance of 1.00 ± 0.51 mm from the pulpal floor, 1.39 ± 0.60 mm from the MBC orifice, and 1.37 ± 0.50 mm from MLC orifice. The width of dentin toward the furcation varies between 0.71 mm and 2.22 mm. Conclusion Middle mesial canal is present in 14.65% of mandibular molars in the Lebanese population, with its orifice located under the pulpal floor. The majority of MMCs join the MBC. Clinical significance Middle mesial canal is not a rare finding in the Lebanese population (14.65%). Clinicians should take time to search for this canal in the isthmus between the main mesial canals.

International audience; The aim of this study was to compare shaping abilities of Protaper Gold® (PTG) and 2Shape® (TS) by using a new automatic process and micro-computed tomography (Micro-CT). 32 first mandibular molars with two separate mesial canals were selected. Only mesial roots were prepared with PTG and TS. Pre- and post-operative scans were performed using Micro-CT to provide volumes with a voxel size of 20 μm. Volumes, non-instrumented area, amount of transportation and centering ability in coronal, middle and apical third shaping time and procedural errors were recorded. TS and PTG increased the endodontic volume of 2.98 mm3 (±1.56) and 3.21 mm3 (±1.78) respectively with no statistical difference (p = .168) and no procedural errors. No significant difference was found concerning canal transportation among groups but only within the same group PTG (p value

Objectives: The present study aimed in assessing the coronal defects after access cavity finishing and refinement by micro. Methods: Access cavities on thirty molars were prepared using a diamond bur. To finish and refine the access cavity, the Endo-Z was used in group 1 (n=15) and Start X 1 in group 2. Preparation time was recorded. A micro-CT scan was done before and after access preparation. Formation and location of the new defects were registered, the extension of defects calculated and the direction of the extension registered, preparation time and surface roughness determined (P < 0.05). Results: Preparation time was significantly higher with ultrasonics (P .05). Conclusion: Ultrasonic tips induced new cracks. Both instruments caused the extension of cracks. Ultrasonic tips requires more time and results in significantly rougher surfaces.

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 digital camera (Olympus, E330, DC 7.4V) coupled with a microscope (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 > 0.05). The M-wire Reciproc ® 25 had a higher mean value for transportation and a lower mean value for centering ability (P 0.05). Le M-wire Reciproc ® 25 avait une valeur moyenne plus elevee que le WaveOne® primary pour le transport apical et une valeur moyenne plus faible pour le centrage canalaire (p

AIM Flare-ups following a root canal treatment are still a major problem both to the patient and to the clinician. Its definition, etiology, incidence, and risk factors have been the subject of long-standing debate. We conducted this study to investigate the incidence of flare-ups after a single-visit treatment and to identify the factors associated with the flare-up index (FUI). MATERIALS AND METHODS All patients treated by postgraduate residents in endodontic specialty at Saint Joseph University of Beirut from June 2018 to January 2019 were invited to participate in the study. After a routine root canal treatment, patients were given a questionnaire to fill after 24 hours-48 hours-7 days, covering a postoperative assessment of symptoms using the visual analogue scale (VAS) and FUI. Patients who experienced a severe postoperative pain and/or swelling were identified and categorized as having a flare-up. RESULTS A total of 423 patients (age: 39.76 ± 12.428 years) were included in the study. The incidence of flare-up was 1.9%. The mean FUI was 5.94 ± 5.646 and was highly correlated with the VAS score (p 24 hours) before treatment (p < 0.001), and tooth type (p = 0.013). CONCLUSION FUI should be used in further studies to confirm our results since it is a valid quantitative method to assess this clinical phenomenon. CLINICAL RELEVANCE Endodontists should take into consideration the diagnosis and the history of preoperative symptoms since it plays an important role in predicting the occurrence of flare-ups and the success of the treatment.

The aim of this in vitro study was to assess the dentinal tubule penetration of three different sealers, AH Plus, BC Sealer and a novel tricalcium silicate sealer (NTS). Ninety-six human maxillary central incisors were divided into three experimental groups (n = 32) and were filled with gutta-percha using a single-cone technique in conjunction with one of the three sealers: AH Plus, BC Sealer or NTS. The roots in each group were cross-sectioned at 1 and 5 mm from the root apex, and the surfaces were examined under confocal laser scanning microscopy (CLSM). The sealer penetration depths were measured at their maximum depths and at four circumferential depths (12, 3, 6 and 9 o’clock) and were evaluated using ImageJ software (ImageJ, NIH). The maximum and mean penetration depths were significantly higher at 5 mm compared to 1 mm from the apex in the AH Plus (p

AIM To compare two preparation systems and two sonic irrigation devices during the removal of root filling material from oval distal canals of extracted mandibular molars. METHODOLOGY The distal canals in 40 extracted mandibular molars were shaped using the ProTaper Next system (Dentslpy Sirona, Ballaigues, Switzerland), filled with Gutta Percha X2 (Dentsply Sirona), along with AH Plus sealer (Dentsply De Trey, Konstanz, Germany) and randomly divided into two groups (n = 20) according to volume of initial filling, preparation diameter and working length. One group was retreated using the Reciproc system (VDW, Munich, Germany), and the other using the 2Shape system (Micro-Mega, Besancon, France). A micro-CT scan was taken after the initial root filling and after retreatment to evaluate the volume of filling material remnants. The teeth were divided into four groups to test the supplementary effect of two sonic irrigation devices on removing filling material: Eddy (VDW) and MM1500 (Micro-Mega). In the first and second groups, 2Shape was followed subsequently by MM1500 and Eddy; in the third and fourth groups, Reciproc was followed by MM1500 and Eddy. A third micro-CT was taken to compare the remaining root filling material in all groups. Wilcoxon's signed rank tests, Mann-Whitney and Kruskal-Wallis tests were used for statistical analysis. RESULTS No significant difference was found for the volume of filling material removed between the Reciproc and 2Shape in the entire canal (P = 0.355). The volume dropped significantly from its initial value after removing the bulk of the root filling by 95.8% (from 4.71 to 0.22 mm3 ) with the 2Shape (P

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.

Objective The objective of this ex vivo study was to evaluate canal transportation and centring ability of Reciproc and Reciproc blue systems in curved root canals with or without prior use of PathFile rotary system (PF) using Cone Beam Computed Tomography (CBCT). Methods One hundred and twenty curved root canals from maxillary and mandibular premolars were selected. Canals were divided randomly into 4 groups (n=30): Reciproc 25 (R25), (PF+R25), Reciproc Blue 25 (RB25), (PF+RB 25). Specimens were scanned before and after root canal preparation. Using CBCT, root canal transportation and centring ability was assessed by measuring the shortest distance from the edge of uninstrumented canal to the periphery of the root (mesial and distal) before and after preparation. Data were analysed using a one-way analysis of variance and Tukey test. The p value was set at 0.05. Results Less transportation and better centring ability occurred when PF was used before R25 or RB25 (P

We assessed the efficiency of two shaping file systems and two passive ultrasonic irrigation (PUI) devices for removing filling material during retreatment. The mesial canals from 44 extracted mandibular molars were prepared and obturated. The teeth were randomly divided into two groups, and then one group was retreated with Reciproc R25 (VDW, Munich, Germany) (n = 44) and the other group was retreated with 2Shape (TS, Micro Mega, Besan&ccedil, on, France) (n = 44). A micro-computed tomography (CT) scan was taken before and after the retreatment to assess the volume of the filling material remnants. The teeth were then randomly divided into four groups to test two different PUI devices: Irrisafe (Satelec Acteon Group, Merignac, France) and Endo Ultra (Vista Dental Products, Racine, WI, USA). The teeth in Group A were retreated with 2Shape to test the Endo Ultra (n = 22) device, the teeth in Group B were retreated with 2Shape in order to test the Irrisafe (n = 22) device, the teeth in Group C were retreated with Reciproc to test the Endo Ultra (n = 22) device, and Group D was retreated with Reciproc to test the Irrisafe (n = 22) device. A third micro-CT scan was taken after the retreatment to test the PUIs. The percentage of Gutta-Percha (GP) and sealer removed was 94.75% for TS2 (p &lt, 0.001) and 89.3% for R25 (p &lt, 0.001). The PUI significantly enhanced the removal of the filling material by 0.76% for Group A (p &lt, 0.001), 1.47% for Group B (p &lt, 0.001), 2.61% for Group C (p &lt, 0.001), and by 1.66% for Group D (p &lt, 0.001). 2Shape was more effective at removing the GP and sealer during retreatment (p = 0.018). The supplementary approach with PUI significantly improved filling material removal, with no statistical difference between the four groups (p = 0.106).

Objective: This study aimed to compare the frequency of dentinal microcracks after root canal shaping with 2 reciprocating (Reciproc and WaveOne) and 1 combined continuous reciprocating motion twisted files adaptive (TFA) rotary system. Materials and Methods: Ninety molars were chosen and divided into three groups of 30 each. Root canal preparation was achieved by using Reciproc R25, Primary WaveOne and TFA systems. All the roots were horizontally sectioned at 15, 9, and 3 mm from the apex. The slices were then viewed each under a microscope at × 25 magnification to determine the presence of cracks. The absence/presence of cracks was recorded, and the data were analyzed with a Chi-square test. The significance level was set at P < 0.05. Results: Instrumentation with Reciproc produced significantly more complete cracks than WaveOne and TFA (P = 0.032). The TFA system produced significantly less cracks then the Reciproc and WaveOne systems apically (P = 0.004). Conclusions: Within the limits of this study, the TFA system caused less cracks then the full reciprocating system (Reciproc and WaveOne). Single-file reciprocating files produced significantly more incomplete dentinal cracks than full-sequence adaptive rotary motion.

Aim To characterize a novel mechanically mixed mineral trioxide aggregate product (MM-MTA, MicroMega, Besancon, France) and to investigate the physical and chemical properties in comparison with ProRoot MTA (Dentsply, Tulsa Dental, Johnson City, TN, USA) and MTA Angelus (Angelus, Londrina, Brazil). Methodology The three materials were mixed according to manufacturer's instructions. Specimens 10 mm in diameter and 2 mm high were prepared and characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD) analysis after 1-day and 28-day storage in physiological solution. Calcium ion leaching in solution and pH of the elution were also assessed. Furthermore, the setting time, radiopacity and material porosity were investigated. Statistical analysis was performed by anova and Tukey's post hoc tests. Results All the MTAs tested were composed primarily of tricalcium silicate and bismuth oxide. In addition, MM-MTA exhibited additional peaks for chlorine evident in the EDS analysis; calcium carbonate was present in the set material detected by XRD. Calcium hydroxide was present in the set ProRoot MTA and MTA Angelus. Calcium ion leaching and alkalization of the storage solution were demonstrated in all the materials. Both MM-MTA and MTA Angelus had a shorter setting time when compared to ProRoot MTA (P

The purpose of this study was to evaluate and compare canal transportation of curved root canals by using 3 nickel-titanium systems: Reciproc, WaveOne, and Twisted Files Adaptive (TF).Twenty-four extracted human mandibular molars with 2 separate mesial canals and severe angle of curvature were selected. Individual canals were divided randomly to 1 of the 3 experimental groups: Reciproc group, reciprocating instrumentation with Reciproc R25; WaveOne group, reciprocating instrumentation with the Primary WaveOne file; and TF Adaptive group, Adaptive Rotary Motion with the TF files. Each group consisted of 16 root canals. Specimens were scanned before and after root canal preparation with an isotropic resolution of 20 μm by using micro-computed tomography. The degree of canal transportation, in addition to instruments' centering ability, was recorded.Less transportation occurred with TF Adaptive rotary instruments (P.0001). The mean degree of canal transportation in the apical third was significantly lower with TF Adaptive group (P.0001). No significant difference was found between Reciproc and WaveOne systems (P = 1.000). Mean centering ratio was the highest statistically with TF Adaptive (P.0001), followed by WaveOne, and was minimal with Reciproc (P.05).The TF Adaptive system was found to have less canal transportation and better centering ability when compared with the reciprocating groups.

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.

Aim Compare the efficiency in removing two calcium hydroxide [Ca(OH)2] preparations from root canal and apical third using single use syringe, ultrasonics and RinsEndo® with saline solution. Materials and methods One hundred and eighty human singlerooted teeth were instrumented using ProTaper® rotary system, divided into two groups according to Ca(OH)2 filling. A: Powder mixed with water, B: Pulpdent®. Each group was divided into three subgroups for the irrigation: A1, B1: Single use syringe; A2, B2: Ultrasonics; A3, B3: RinsEndo®. Teeth were split longitudinally, photographed and imported into Adobe Photoshop. The percentage ratios of Ca(OH)2 remaining in the canal and in the apical third were calculated. Data were statistically analyzed using ‘ANOVA two-way’ and ‘univariate tests’. Results (a) Remnants of medicament were found in all teeth, (b) no statistically significant difference in the elimination of both Ca(OH)2 from the entire canal (p = 0.436), however, mixed powder was better eliminated from the apical third (p = 0.005), (c) no statistically significant difference among the irrigation techniques in the whole canal (p = 0.608), though, RinsEndo® and ultrasonics were the most effective in cleaning the apical third (p = 0.032) when mixed powder was used. Conclusion None of the techniques removed completely Ca(OH)2 from the canal. In the apical third, RinsEndo® and ultrasonics were the most effective when mixed powder was used. Clinical significance Ca(OH)2, the most commonly used intracanal dressing, should be completely eliminated before the obturation to assure a good endodontic sealing. Based on the results of this study, RinsEndo® and ultrasonics were the most effective in removal of Ca(OH)2 especially the powder mixed with water presentation. How to cite this article Maalouf L, Zogheib C, Naaman A. Removal Efficiency of Calcium Hydroxide Dressing from the Root Canal without Chemically Active Adjuvant. J Contemp Dent Pract 2013;14(2):188-192.

Aim To compare the histomorphological response of rat dental pulps capped with MM-MTA and ProRoot MTA at 1, 2 and 4 weeks postoperatively. Materials and methods Direct pulp capping with MM-MTA and ProRoot MTA, overlaid with light-cured composite resin, was performed on right and left maxillary first molars of 20 Wistar rats. Animals were killed at 1, 2 and 4 weeks postoperatively. Biopsy samples were stained and viewed by light microscopy to determine dentin bridge formation. Data were statistically evaluated with the Kruskal-Wallis test (p < 0.05). Results Absence of dentin bridge formation at 1 week, partial dentin bridge formation at 2 weeks and complete dentin bridge formation at 4 weeks are observed with MM-MTA and ProRoot MTA. The results showed no statistically significant difference between both materials at 4 weeks. Conclusion Both materials produced similar responses in the pulp when used for pulp capping in intact, caries-free molars of rats. How to cite this article Khalil IT, Sarkis T, Naaman A. MM-MTA for Direct Pulp Capping: A Histologic Comparison with ProRoot MTA in Rat Molars. J Contemp Dent Pract 2013;14(6):1019- 1023.

Introduction Sealers based on tricalcium silicate cement aim at an interaction of the sealer with the root canal wall, alkalinity with potential antimicrobial activity, and the ability to set in a wet field. The aim of this study was to characterize and investigate the properties of a new tricalcium silicate–based sealer and verify its compliance to ISO 6876 (2012). Methods A new tricalcium silicate–based sealer (Bio MM; St Joseph University, Beirut, Lebanon), BioRoot RCS (Septodont, St Maure de Fosses, France), and AH Plus (Dentsply, DeTrey, Konstanz, Germany) were investigated. Characterization using scanning electron microscopy, energy-dispersive spectroscopy, and X-ray diffraction analysis was performed. Furthermore, sealer setting time, flow, film thickness, and radiopacity were performed following ISO specifications. pH and ion leaching in solution were assessed by pH analysis and inductively coupled plasma. Results Bio MM and BioRoot RCS were both composed of tricalcium silicate and tantalum oxide in Bio MM and zirconium oxide in BioRoot RCS. In addition, the Bio MM contained calcium carbonate and a phosphate phase. The inorganic components of AH Plus were calcium tungstate and zirconium oxide. AH Plus complied with the ISO norms for both flow and film thickness. BioRoot RCS and Bio MM exhibited a lower flow and a higher film thickness than that specified for sealer cements in ISO 6876. All test sealers exhibited adequate radiopacity. Conclusions Bio MM interacted with physiologic solution, thus showing potential for bioactivity. Sealer properties were acceptable and comparable with other sealers available clinically.

Gambarini G, Gergi R, Naaman A, Osta N, Al Sudani D. Cyclic fatigue analysis of twisted file rotary NiTi instruments used in reciprocating motion. International Endodontic Journal, 45, 802–806, 2012. Abstract Aim To evaluate the cyclic fatigue fracture resistance of engine-driven twisted file (TF) instruments under reciprocating movement. Methodology A sample of 30 size 25, 0.08 taper NiTi TF instruments was tested in a simulated canal with 60˚ angle of curvature and a 3 mm radius. During mechanical testing, different movement kinematics were used at a constant speed, which resulted in three experimental groups (each group n = 10). The instruments from the first group (G1) were rotated until fracture occurred. The instruments in the second (G2) and third group (G3) were driven under reciprocating movement with different angles of reciprocation. The time of fracture for each instrument was measured, and statistical analysis was performed using one-way analysis of variance followed by Tukey’s Honestly Significant Different test. Results Reciprocating movement resulted in a significantly longer cyclic fatigue life (P

Forty-eight extracted maxillary anterior teeth instrumented with ProTaper system to apical preparations 0.25, 0.40 and 0.60 mm (n = 16 each) were divided into six groups for filling as following: Group 1: Apical preparation 25/100 + gutta-percha/AH Plus sealer, group 2: Apical preparation 25/100 + Resilon/Real Seal, group 3: Apical preparation 40/100 + gutta-percha/AH plus sealer, group 4: Apical preparation 40/100 + Resilon/Real Seal, group 5: Apical preparation 60/100 + gutta-percha/AH plus, group 6: Apical preparation 60/100 + Resilon/Real Seal. All teeth were filled using the warm vertical technique. Horizontal sections at 1, 2 and 3 mm from the apex were observed by SEM under 200 × magnification. Sections were digitally photographed under a stereomicroscope and the images were transferred to a compatible PC for image analysis. The surface area of voids were calculated and compared at all levels; using the Kruskal-Wallis test with Sidak correction and Mann-Whitney U test (p > 0.05). Comparisons within each group (gutta-percha/AH plus and Resilon/Real Seal) showed the presence of voids but there was no significant difference between any level of sectioning for apical preparations of 25 and 40 (p > 0.05). The only difference was in the groups prepared to size 60 and filled with Resilon/ Real Seal which showed significantly more voids than the group filled with gutta-percha/AH plus and especially at the 3 mm level. Conclusion The system Resilon/Real Seal did not achieve better results in terms of sealing ability in the apical third when compared to the conventional gutta-percha/AH plus sealing system. How to cite this article Zogheib C, Naaman A, Medioni E. Evaluation of Apical Filling after Warm Vertical Compaction using Two Different Endodontic Materials: Resilon® and Gutta-Percha. World J Dent 2012;3(2):166-170.

The purpose of this study was to compare canal transportation and centering ability of 2 rotary nickel-titanium (NiTi) systems (Twisted Files [TF] and Pathfile-ProTaper [PP]) with conventional stainless steel K-files.Ninety root canals with severe curvature and short radius were selected. Canals were divided randomly into 3 groups of 30 each. After preparation with TF, PP, and stainless steel files, the amount of transportation that occurred was assessed by using computed tomography. Three sections from apical, mid-root, and coronal levels of the canal were recorded. Amount of transportation and centering ability were assessed. The 3 groups were statistically compared with analysis of variance and Tukey honestly significant difference test.Less transportation and better centering ability occurred with TF rotary instruments (P.0001). K-files showed the highest transportation followed by PP system. PP system showed significant transportation when compared with TF (P.0001).The TF system was found to be the best for all variables measured in this study.

International audience; Introduction: 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)

Background: This study aimed to evaluate the accuracy of two imaging methods in detecting the apical pathology in endodontically treated teeth. Material and Methods: A clinical examination from a sample of 156 teeth of patients treated by students of masters in endodontics at the Care Center of the Faculty of Dentistry at St. Joseph University, Beirut was done after 5 years of follow-up. Periradicular digital radiographs and a cone-beam computed tomography (CBCT)scans were taken and analyzed statistically using both the Exact Fisher tests and McNemar tests. Results: The prevalence of lesions was significantly higher with CBCT (34.8%), whereas for digital radiography (13.8%). The CBCT was revealed more precise to identify periapical lesions. As for the clinical success, the rate was 82.5%. Conclusion: Within the limitations of the present study, CBCT was more reliable in detecting periapical lesions compared with digital periapical radiographs.

Aim To compare and evaluate the shaping ability of several nickel titanium instrument systems with different motions: two reciprocating single-file systems (Reciproc and WaveOne) and one continuous rotation/reciprocation full-sequence system [Twisted File (TF) Adaptive] using micro-computed tomography. Methodology A total of forty-eight mesial canals of mandibular molars with two separate root canals and severe angles of curvature were selected. Canals were divided randomly to one of three experimental groups: group 1, reciprocating instrumentation with Reciproc R25, group 2, reciprocating with the Primary WaveOne file and group 3 ‘Adaptive Rotary Motion’ with Twisted Files. Each group consisted of 16 root canals. Canals were scanned before and after root canal preparation, with a resolution of 20 μm using a micro-computed tomography system. The following parameters were assessed: changes in dentine volume, percentage of unshaped canal walls, degree of canal transportation and centring ability. Data were analysed using analysis of variance and Tukey's post hoc tests test to explore a significant difference in mean dentine removal, mean percentage of noninstrumented canals, mean degree of canal transportation and centring ratio between groups in the apical third and along the entire root canal. The level of significance was set at α = 0.05. Results Preoperatively, there were no differences regarding root canal curvature and volume between experimental groups (P > 0.05). Overall instrumentation led to enlarged canal shapes with no evidence of preparation errors. None of the three groups was able to shape completely the root canal system. Mean dentine removal along the entire canal and in the apical third was significantly higher with Reciproc when compared with TF Adaptive and WaveOne (P = 0.013). Mean degree of canal transportation was significantly lower with TF Adaptive (P

Aim The aim of this study is to evaluate the influence of final canal taper on the sealing ability of Thermafil by using microcomputed tomography (micro-CT). Materials and methods Fifty-four single-rooted teeth were instrumented to apical size 40 taper 4, 6 and 8%. Teeth were divided into three groups. All teeth were filled with Thermafil (Dentsply, Tulsa Dental Products). Using micro-CT, roots were scanned and volume measurements of voids at 1, 3 and 5 mm from the apex were calculated using specialized CT software. Measurements were analyzed statistically with ANOVA followed by Bonferroni multiple comparison correction. Results Data analysis showed that 0.08 preparations provided better results than 0.06 and 0.04% tapered samples especially at 1 mm from the apex. Mean percentage of voids were significantly higher with Thermafil taper 0.06% (p = 0.05). None of the root canals filled teeth were gap free. Root canal preparations with bigger taper exhibited less voids than smaller tapered preparations. Clinical significance In our daily practice, enlarging the apical third (last 3 mm) of root canals to an 8% taper gives a better sealing ability and thus long-term success for our root canal obturations. How to cite this article Zogheib C, Naaman A, Medioni E, Bourbouze G, Arbab-Chirani R. The Quality of Thermafil Obturations with Different Final Apical Tapers: A Threedimensional Microcomputed Tomographic Comparative Study. J Contemp Dent Pract 2012;13(3):322-326.

The aim of the study was to measure the percentage of volume of voids and gaps in the apical third of root canals obturated with two techniques using micro-computed tomography. Fifty-four single-rooted teeth were collected and root canal-prepared. The roots were randomly allocated into two groups; each group was obturated by using thermoplasticized technique with a different material (gutta-percha and Topseal for Thermafil, Resilon and RealSeal for RealSeal 1). Roots were then scanned, and volume measurements for voids and gaps in the obturated roots were carried out using specialized CT software. Percentage of gaps and voids was calculated. The present study showed that none of the root canal-filled teeth was gap free. Student t test was conducted. No significant difference was found between Thermafil and RealSeal 1 concerning percentage of voids in the apical third (P > 0.05). Both materials showed statistically significant difference between the levels where 1 mm showed the highest volume of voids (P

IntroductionThe purpose of this study was to evaluate the influence of the insertion depth of an ultrasonically oscillating file on the ability to remove dentin debris from simulated canal irregularities in an extracted tooth model of a straight root canal and its influence on the flow of irrigant in both straight and curved canals.MethodsA tooth model with artificial depressions in 1 canal wall at 0.5, 2, 4, and 6 mm from the working length was used. Ultrasonic-activated irrigation was performed with the file inserted 1, 2, 3, 4, or 5 mm short of the working length. Dye penetration and high-speed recordings of the flow in straight and curved canals showed the static and dynamic behavior of the flow during ultrasonic activation.ResultsThe overall cleaning efficacy decreased with increasing distance between the file and the apex, with the depressions next to the file and within 3 mm in front of the file being the cleanest. The flow observed from the visualization experiments matched this distance, suggesting a direct relation between flow and cleaning. The observed flow depth increased with increasing power setting; the curvature of the root canal had no influence on the flow depth. High-speed imaging showed a start-up phase with deeper fluid activation than in the steady phase afterward.ConclusionsThe ultrasonically oscillating file could remove dentin debris up to 3 mm in front of the file tip, coinciding with the extent of the observed flow. The root canal curvature had no influence on the irrigant flow.

The objective of this study is to study the influence of final canal taper on the sealing ability of Real Seal 1 by using micro-computed tomography (micro-CT). Fifty-four single-rooted teeth were instrumented to apical size of 40 taper 4, 6, and 8. The teeth were divided into three groups. All teeth were filled with Real Seal 1 (RS1; SybronEndo, Orange, CA, USA). Roots were then scanned with mico-CT, and volume measurements of voids in the apical third and in sections at 1, 3, and 5 mm from the apex were calculated in the obturated roots using specialized CT software. Measurements were analyzed statistically by using ANOVA followed by Bonferroni multiple comparison correction. Data analysis showed that 0.08% and 0.06% apical tapered RS1 obturations provided better results than 0.04% tapered samples. The present study showed that none of the root canals filled teeth were gap free. Mean percentages of voids were significantly higher with Real Seal 1 taper 0.04% (P = 0.05).There was no significant difference with 0.06 and 0.08 final taper. For Real Seal 1 technique 0.06 and 0.08 tapered preparations seem to be more optimal. At 1 mm, final taper 0.08 showed less voids and gaps than the two other final tapers. In our daily practice, enlarging the apical third (last 3 mm) of root canals to an 8% taper is necessary to achieve a better sealing ability and thus long-term success for our root canal obturations.

This in vitro study sought to evaluate the influence of calcium hydroxide on the sealing ability of vertically condensed warm gutta-percha filling. Sixty single-rooted teeth were instrumented with a rotary system and divided randomly into two groups of 26 teeth each; the remaining eight teeth were divided into two groups of four to serve as negative and positive controls. The canals in the first group were filled with calcium hydroxide paste while the canals in the second group received no medication. Seven days after incubation, root canal dressings were removed by irrigation, using 5.25% sodium hypochlorite associated with ultrasonics and 50% citric acid. All specimens were filled using the warm gutta-percha vertical compaction technique, placed in test tubes containing India ink, and centrifuged at 30 G for five minutes; at that point, the dye penetration level was scored. Under the conditions of this study, the calcium hydroxide group showed significantly greater dye penetration than the non-medicated group.

The aims of this in vitro study were to evaluate debris and smear layer elimination capability effectiveness of 5.25% sodium hypochlorite (NaOCl) after calcium hydroxide removal from the root canal and to determine if ethylenediaminetetraacetic acid (EDTA) and citric acid have any additional effects on debris and smear layer removal.All irrigation regimens are associated with ultrasonics. Thirty-six pulpless single-rooted teeth were divided into three groups on the basis of the irrigation regimen, namely 5.25% NaOCl alone, 5.25% NaOCl with 17% EDTA pH 7 (NaOCl-EDTA), and 5.25% NaOCl with 50% citric acid (NaOCl-CA). All root canals were instrumented with the Protaper rotary system (Dentsply-Maillefer, Ballaigues, Switzerland) using a crown-down approach. The apical foramen of each tooth was enlarged to a size 30 with a 0.09 taper. After longitudinal sectioning, the dentin walls were microphotographed using scanning electron microscopy (SEM) at a 1500x magnification. Using a grid and a 5-step scale these microphotographs were scored by three investigators in order to evaluate debris and smear layer residuals. Data were statistically evaluated using Kruskal-Wallis and Mann-Whitney tests.In the coronal third the lowest score obtained with NaOCl-CA was similar to NaOCl-EDTA. When using NaOCl-EDTA, mean debris scores were similar to the control group (NaOCl) and lower than NaOCl-CA in the middle and apical thirds. Regarding the mean smear layer score, NaOCl-CA was the lowest in the coronal, middle, and apical thirds with a statistically significant difference (p0.001).When the total surface of the root was evaluated, NaOCl-EDTA was superior in removing debris, but the association of NaOCl-CA enabled the most effective removal of the smear layer.

Aim An experimental comparison of the Root ZX apex locator with the real measurement of the root canal length was carried out using a saline gel to simulate the periodontium. Methodology Lengths were taken when the needle reached the 0.5 mark and the Apex mark on the meter. These measurements were then compared with a calculated reference length representing the real length of the root canal. Reliability was assessed using Student’s t-test. Precision was assessed using the mean and standard deviation of differences. Results The Root ZX gave measurements within a range of 0.5 mm in 84.72% of the cases. The intra-operator and inter-operator variabilities were not statistically significant (P > 0.05). Conclusions The Root ZX is not capable of detecting the ‘0.5 mm from the foramen’ position and thus, should only be used to detect the foramen (major diameter).