Emre Nagas

Hacettepe University, Engüri, Ankara, Turkey

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Publications (24)37.05 Total impact

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    ABSTRACT: AimTo evaluate the effect of prior application of several intracanal medicaments on the push-out bond strength of ProRoot MTA and Biodentine.MethodologySixty freshly-extracted maxillary anterior teeth were sectioned below the cementoenamel junction, and the root canals instrumented using rotary files. Thereafter, a parallel post drill was used to obtain a standardized root canal dimension. The roots were randomly assigned into one of the following groups with respect to the intracanal medicament applied: Group 1. Calcium hydroxide (CH) powder (Merck, Darmstadt, Germany) mixed with distilled water; Group 2. A mixture of metronidazole, ciprofloxacin, and minocycline (Triple Antibiotic Paste); Group 3. A combination of amoxicillin and clavulanic acid (Augmentin, Champs Pharmacy, San Antonio, TX, USA); Group 4. An antibiotic-corticoid compound paste (Ledermix Riemser, Greifswald, Germany); and Group 5. No medicament (Control). Following removal of medicaments with instrumentation and irrigation, the roots were cut into 1-mm-thick parallel transverse sections in a coronal-to-apical direction (5 slices/tooth). Thereafter, the specimens were divided into two subgroups according to the calcium silicate cement applied (n=30/group): 1. ProRoot MTA (Dentsply Tulsa Dental, Tulsa, OK, USA) and 2. Biodentine (Septodont, Saint-Maur-des-Fosses, France). A push-out test was performed and the data were analyzed statistically using two-way ANOVA and Tukey's post-hoc test.ResultsRegardless of the type of intracanal medicament used, Biodentine had significantly higher bond strength than MTA (p <0.05). The highest push-out bond strength results were obtained in CH-treated dentine. Compared with other medicaments, this value was only significantly higher than that of Ledermix (p<0.05). In both the MTA and Biodentine groups, pairwise comparisons between other medicaments showed similar debonding values (p>0.05).Conclusions Biodentine had a higher bond strength to root canal dentine than ProRoot MTA. Prior CH in distilled water intracanal placement increased the dislodgment resistance of both calcium silicate cements.This article is protected by copyright. All rights reserved.
    International Endodontic Journal 01/2015; · 2.27 Impact Factor
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    ABSTRACT: The aim of this study was to evaluate the influence of a calcium silicate-based sealer (iRoot SP), with or without a core material, on bond strength to radicular dentin, in comparison with various contemporary root filling systems. Root canals of freshly extracted single-rooted teeth (n = 60) were instrumented using rotary instruments. The roots were randomly assigned to one of the following experimental groups: (1) a calcium silicate-based sealer without a core material (bulk-fill); (2) a calcium silicate-based sealer + gutta-percha; (3) a calcium silicate-based sealer + Resilon; (4) a methacrylate resin-based sealer (RealSeal SE) + Resilon; (5) an epoxy resin-based sealer (AH Plus) + gutta-percha, and (6) a mineral trioxide aggregate-based endodontic sealer (MTA Fillapex) + gutta-percha. Four 1-mm-thick sections were obtained from the coronal aspect of each root (n = 40 slices/group). Push-out bond strength testing was performed at a cross-head speed of 1 mm/min, and the bond strength data were analyzed statistically by one-way analysis of variance and Tukey tests (p < 0.05). The highest and lowest debonding values were obtained for the calcium silicate-based sealer bulk-fill and mineral trioxide aggregate-based endodontic sealer + gutta-percha groups, respectively (p < 0.05). It was concluded that the calcium silicate-based sealer showed higher resistance to dislocation in the bulk-filled form than in conjunction with the tested core filling materials. When the calcium silicate-based sealer was placed in bulk, its dislocation resistance was similar to that of commonly used sealer + core root filling systems. Thus, the concept of using a calcium silicate-based sealer in bulk can be more easily advocated in clinical practice.
    Brazilian oral research 09/2014; 28(1):1-7.
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    ABSTRACT: The aim of the study was to evaluate the regional push-out bond strength of mineral trioxide aggregate (MTA) after exposure to sodium hypochlorite (NaOCl), ethylenediaminetetraacetic (EDTA), and peracetic acid (PAA) irrigation solutions. 1-mm-thick longitudinal slabs of root dentin were obtained from freshly extracted human canine teeth (n = 80). Simulated root perforation defects, 1 mm in diameter, were prepared in the coronal, middle, and apical thirds of radicular dentin. Mineral trioxide aggregate was placed into the cavities, and the specimens were stored for 1 week at 37°C. Thereafter, the specimens were randomly divided into four groups (n = 20) according to the irrigation solution applied over the repair sites: Group 1-10 ml of 5.25% NaOCl for 10 min; Group 2-10 ml of 5.25% NaOCl for 10 min, followed by 5 ml 17% EDTA for 5 min; Group 3-10 ml of 5.25% NaOCl for 10 min, followed by application of 5 ml 1% PAA for 5 min; and Group 4-no irrigation. Push-out test was performed at a crosshead speed of 1 mm/min. Debonding values were compared statistically using two-way analysis of variance and Tukey tests (P < 0.05). The push-out bond strength of MTA was not affected by the type of irrigation solution or location of the perforation defects (both P < 0.05). Stereomicroscopic inspection of the samples showed that the bond failure was predominantly adhesive. Exposure of repaired root perforations to 5.25% NaOCl, 17% EDTA, or 1% PAA does not alter the dislocation resistance of MTA at different locations of root dentin.
    Dental Traumatology 09/2013; · 1.21 Impact Factor
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    ABSTRACT: Abstract Objective. To compare the smear layer removal efficacy and erosive effects of different irrigation protocols under clinical and laboratory conditions. Materials and methods. Mandibular third molars (n = 32) of 30-45 year-old patients were instrumented with rotary files and were randomly assigned to one of the following groups for final irrigation: (1) 5.25% NaOCl; (2) 17% EDTA; and (3) BioPure MTAD. Thereafter, the teeth were immediately extracted and processed for micromorphological investigation. In vitro specimen pairs were prepared by repeating the clinical experiments on freshly-extracted mandibular third molars. To compare open and closed systems, laboratory experiments were repeated on 32 additional teeth with enlarged apical foramen. The cleanliness of the root canals and the extent of erosion were assessed by environmental scanning electron microscopy. Results. Specimens prepared under clinical and laboratory conditions had similar cleanliness and erosion scores (p > 0.05). Under both conditions, the tested solutions were more effective in removing the smear layer in the coronal and middle regions than in the apical one. Comparison of closed and open systems showed similar levels of cleanliness and erosion in all regions (p > 0.05), with the exception of 17% EDTA showing significantly higher levels of cleanliness and erosion in the apical third of open-end specimens. Conclusions. Based on clinical correlates of in vitro root canal cleanliness and erosion, laboratory testing of root canal irrigants on extracted teeth with closed apices can serve as a reliable method to simulate the clinical condition. EDTA was the most effective final irrigation solution in removing the smear layer at the expense of yielding the greatest erosive effect.
    Acta odontologica Scandinavica 02/2013; 71(5). · 1.41 Impact Factor
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    ABSTRACT: Objectives: The purpose of this study was to investigate the presence and the incidence of a third canal in the mesial root of the permanent mandibular first molars using micro-computed tomography (micro-CT) and to describe the morphology of mandibular first molar's root canal anatomy. Methods: A total of 100 extracted mandibular first molars were randomly collected. Teeth were scanned by using micro-computed tomography device (SkyScan 1074, Aartselaar, Belgium). These images were reconstructed three-dimensionally by using software NRecon (SkyScan 1074, Kontich, Belgium). After constructing, three-dimensional images exhibiting the shape of the roots were analyzed by using 3D-Doctor software programme (v.3.5 Able Software Corp, Lexington,MA). Thereafter, the number of the middle mesial canals were evaluated. Results: The results of this study indicate that a middle mesial canal present in 12 % of mandibular first molars. In this study, the middle mesial canals merged with the mesiobuccal or mesiolingual canals. Conclusions: 12% of mandibular first molars had a middle mesial canal which is significantly important from a clinical point of view. The possibility of additional canal in the mesial root should be anticipated in mandibular first molars. Micro-CT is an effective tool for the detection such extra canals in teeth.
    PER/IADR Congress 2012; 09/2012
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    ABSTRACT: Objectives: To evaluate the effect of calcium hydroxide (Ca(OH)2) removal techniques on the accuracy of Root ZX in enlarged root canals and compare the efficiency of these techniques for the removal of Ca(OH)2from root canals. Methods: 90 freshly extracted human maxillary incisors were prepared with ProTaper rotary system to an apical size F3. During the preparation, root canals were irrigated with 2mL of 2.5% NaOCl solution between each file and then filled with injectable Ca(OH)2 paste. Specimens were stored for 1 week at 37°C in 100% relative humidity. 6 teeth assigned randomly as control group (G) and six groups (n=14) arranged as follows: G1: only irrigation with 10mL 0,9% saline, G2: same manner as G1 and instrumentation with master apical file (MAF), G3: 10mL 17% EDTA, G4: G3 and MAF, G5: 10mL 5,25% NaOCl, G6: G5 and MAF. All specimens were mounted in an experimental apparatus for measuring root lengths via Root-ZX. Electronic measurements compared with actual canal lengths that were determined at beginning of study by inserting #10 file until the tip was visualized (12.8× magnification) just within the apical foramina. After all roots sectioned longitudinally along the length of the instrumented canals, each half was examined with a stereomicroscope at 500× magnification and photographed digitally. Residual Ca(OH)2 in root canals were measured via COMEF 4.3 software. The measurements of residual Ca(OH)2was analyzed with oneway ANOVA with post-hoc LSD test, and lengths measurements was analyzed with Kruskal-Wallis with post-hoc Dunn’s test. Results: Significantly less residual material was obtained in G4 and G6 than the other groups (p< 0.05). Root ZX was highly accurate in G4 and G6. Conclusions: None of the techniques removed the Ca(OH)2 dressing completely. Remaining Ca(OH)2 influenced the accuracy of RootZX.
    PER/IADR Congress 2012; 09/2012
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    ABSTRACT: The objective of this study was to evaluate the effect of ethylenediaminetetraacetic acid (EDTA) on root fracture with respect to various concentrations at different time exposures. A total of 48 mandibular incisors were selected. Eight nonprepared roots were selected as a negative control. The remaining 40 specimens were instrumented with rotary files and randomly assigned to one of the following groups for final irrigation: (1) 10 mL distilled water for 10 minutes (positive control); (2) 10 mL of 17% EDTA for 1 minute + 10 mL of 1% NaOCl for 1 minute; (3) 10 mL of 5% EDTA for 1 minute + 10 mL of 1% NaOCl for 1 minute; (4) 10 mL of 17% EDTA for 10 minutes + 10 mL of 1% NaOCl for 1 minute; (5) 10 mL of 5% EDTA for 10 minutes + 10 mL of 1% NaOCl for 1 minute. Thereafter, the root canals were filled by using AH26 root canal sealer with a single-cone technique. The specimens were loaded vertically at 1 mm/min crosshead speed until vertical root fracture occurred. Results were evaluated statistically with 1-way analysis of variance and Student's t test. Statistically significant differences were detected among the groups (P < .05). The highest mean fracture resistance was obtained from the group treated with 5% EDTA for 10 minutes. This is about 2 times more than the weakest mean fracture resistance, which was obtained from the 17% EDTA-10 minute group. The fracture resistances of endodontically treated roots were found to be differently affected by the various concentrations of EDTA at different time exposures.
    Journal of endodontics 08/2012; 38(8):1110-3. · 2.95 Impact Factor
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    ABSTRACT: To prepare the post apace, some of the root-canal filling material has to be removed, which can affect the apical seal. The aim of this study was to compare the effect of immediate post space preparation to that of delayed post space preparation on apical sealing using three different endodontic sealers and obturation techniques.Materials and methodsIn total, 90 decrowned single-rooted human teeth were studied. After root canals were prepared with 0.06 tapered nickel–titanium rotary files to size 30, the roots were categorized randomly into three experimental groups according to the obturation material: (1) AH plus/gutta-percha; (2) Sealite Ultra/gutta-percha; and (3) Epiphany/Resilon. Furthermore in all groups, specimens were categorized randomly into three subgroups according to the obturation technique (n = 10): (1) single cone; (2) cold lateral compaction; and (3) System B + Obtura. After root-canal filling, post space preparation was immediately performed in Group 1, after 24 hours in Group 2, and after 7 days in Group 3. Apical leakage was measured using the fluid-filtration method. Statistical analysis was performed using the Kruskal–Wallis test and Wilcoxon signed ranks test at P < 0.001.ResultsRegardless of the obturation technique and sealers used, significantly better (P < 0.001) sealing was achieved at the apical ends using delayed post space preparation than with immediate post preparation. The obturation techniques tested did not significantly affect leakage values. The following statistical ranking of fluid filtration values was obtained for the obturation materials: Epiphany/Resilon > Sealite Ultra/gutta-percha > AH plus/gutta-percha (P < 0.001).Conclusion To reduce apical leakage, clinicians should use AH plus together with any of the obturation techniques after 7 days of obturation.
    Journal of dental sciences 07/2012; · 0.47 Impact Factor
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    ABSTRACT: The purpose of this study was to evaluate the effects of intraradicular moisture conditions on the push-out bond strength of root canal sealers. Eighty root canals were prepared using rotary instruments and, thereafter, were assigned to 4 groups with respect to the moisture condition tested: (1) ethanol (dry): excess distilled water was removed with paper points followed by dehydration with 95% ethanol, (2) paper points: the canals were blot dried with paper points with the last one appearing dry, (3) moist: the canals were dried with low vacuum by using a Luer adapter for 5 seconds followed by 1 paper point for 1 second, and (4) wet: the canals remained totally flooded. The roots were further divided into 4 subgroups according to the sealer used: (1) AH Plus (Dentsply-Tulsa Dental, Tulsa, OK), (2) iRoot SP (Innovative BioCeramix Inc, Vancouver, Canada), (3) MTA Fillapex (Angelus Indústria de Produtos Odontológicos S/A, Londrina, Brasil), and (4) Epiphany (Pentron Clinical Technologies, Wallingford, CT). Five 1-mm-thick slices were obtained from each root sample (n = 25 slices/group). Bond strengths of the test materials to root canal dentin were measured using a push-out test setup at a cross-head speed of 1 mm/min. The data were analyzed statistically by two-way analysis of variance and Tukey tests at P = .05. Irrespective of the moisture conditions, iRoot SP displayed the highest bond strength to root dentin. Statistical ranking of bond strength values was as follows: iRoot SP > AH Plus > Epiphany ≥ MTA Fillapex. The sealers displayed their highest and lowest bond strengths under moist (3) and wet (4) conditions, respectively. The degree of residual moisture significantly affects the adhesion of root canal sealers to radicular dentin. For the tested sealers, it may be advantageous to leave canals slightly moist before filling.
    Journal of endodontics 02/2012; 38(2):240-4. · 2.95 Impact Factor
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    ABSTRACT: To evaluate the translucency characteristics of new flowable bulk-filling resin composites at various thicknesses. Experimental short fibre-reinforced composite was also tested. Two new brands of flowable bulk composites (Venus Bulk Fill and SureFil SDR Flow), experimental short fibre-reinforced resin composite (FC) and, as control, conventional flow (Filtek Supreme Flow XT A3) and universal (Filtek Universal Supreme XTE A3B) resin composites were investigated. Translucency parameter was calculated for various thicknesses of composite (1, 2, 3, 4, 5 and 6 mm) over white and black backgrounds using spectrophotometry to determine the CIELAB values of each specimen. Data were statistically analysed with analysis of variance. Translucency values significantly correlated with thickness of resin composite specimens (P < 0.05). For the new types of flowable bulk-filling material, translucency was observed for thicknesses up to 5 to 6 mm, whereas for experimental FC composite, the effect was observed up to 4 to 5 mm, and for control flow and universal filling composites, up to 2 to 3 mm. New flowable bulk-filling resin composites have less masking ability than conventional universal filling resin composite materials, which should be taken into account when optimum colour match and aesthetic results are to be achieved.
    The Chinese journal of dental research: the official journal of the Scientific Section of the Chinese Stomatological Association (CSA) 01/2012; 15(1):31-5.
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    ABSTRACT: The aim of this study was to compare the in vitro reduction of a bacterial population in a root canal by mechanical instrumentation using three rotary systems and hand instrumentation technique. The root canals contaminated with a suspension of Enterococcus faecalis were instrumented using ProTaper, K3, HeroShaper and K-file hand instrumentation technique. Later the root canals were sampled. After serial dilutions, samples were incubated in culture media for 24 h. Bacterial colonies were counted and the results were given as number of colony-forming units per millilitre. The results showed that all the canal instrumentation systems reduced the number of bacterial cells in the root canals. Statistically, ProTaper instruments were more effective in reducing the number of bacteria than the other rotary files or hand instruments.
    Australian Endodontic Journal 12/2011; 37(3):128-33. · 0.74 Impact Factor
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    ABSTRACT: The purpose of this study was to compare the amount of apically extruded irrigant using 2 Ni-Ti rotary systems. Forty mandibular premolars with single canals were randomly assigned into 4 groups. Flower arrangement foam cubes were weighed with a precision balance before being attached to the apical portions of all teeth. In group 1, preparation was completed with ProTaper files. In group 2 canals were prepared with RaCe files. In groups 1 and 2, the irrigant was delivered with a 30-gauge conventional dental needle. In groups 3 and 4, teeth were prepared as in groups 1 and 2 with the exception that the irrigant was delivered with a side-vented irrigation needle. The weight of the extruded material (irrigant and debris) for each group was calculated by comparing the pre- and postinstrumentation weights of the foams used for periapical modeling. Obtained data were analyzed by Kruskal-Wallis and Mann-Whitney U tests, with P equals .05 as the level for statistical significance. ProTaper files used with regular needle irrigation had the highest fluid extrusion. The lowest irrigant extrusion was observed with the RaCe system combined with a side-vented irrigation needle. Within the limitations of this study, it can be concluded that irrigation needle and rotary instruments have an effect on the amount of extruded root canal irrigant.
    Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology, and Endodontology 07/2011; 112(4):e31-5. · 1.50 Impact Factor
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    ABSTRACT: To evaluate the effect of plunger diameter on the push-out bond strength of different root filling materials to root canal dentine. Freshly extracted human incisors (n=90) were decoronated, and the root canals were enlarged with post drills. Prepared roots were placed into a custom alignment apparatus to embed the roots vertically within self-curing acrylic resin. The specimens were randomly assigned into three groups according to the root filling system used: gutta-percha/AH Plus; Resilon/Epiphany; and fibre-reinforced composite (FRC)/Duolink resin cement. After filling, the specimens were further subdivided according to the diameter of the plunger used to employ the debonding force: 0.75, 1 and 1.25 mm. Intra-radicular bond strength was measured using the push-out test at a cross-head speed of 1 mm min(-1) . The data were analysed statistically using Kruskal-Wallis test with Bonferroni correction at P = 0.05. Regardless of the plunger diameter, FRC yielded the highest bond strength, followed by gutta-percha and Resilon, respectively (P<0.001). In all groups, greater plunger diameter resulted in an apparent increased bond strength, but the differences were only significant in the FRC group, with the 1.25-mm plunger generating higher debonding values compared with that of its 0.75- and 1-mm versions (P<0.001). In the gutta-percha and Resilon groups, the majority of specimens had adhesive failures. Roots filled with FRC exhibited more cohesive failures than those of the other test groups. Different plunger diameters are associated with significantly different intra-radicular push-out bond strengths of root filling systems.
    International Endodontic Journal 07/2011; 44(10):950-5. · 2.27 Impact Factor
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    ABSTRACT: The objective of this study was to investigate and compare the effect of different light-emitting diode (LED) polymerization modes on the bond strength of a methacrylate-based sealer used with Resilon or gutta-percha. Forty extracted single-rooted teeth were sectioned off below the cementoenamel junction, and the root canals were instrumented by using rotary instruments to ISO #30/0.06 taper. The roots were randomly assigned into 1 of the following groups for root canal obturation: (1) RealSeal + Resilon and (2) RealSeal + gutta-percha. In each group, specimens were further subgrouped according to the LED polymerization mode used to cure RealSeal: (1) standard (20 seconds of maximum intensity) and (2) exponential (5 seconds of exponential power increase, followed by 15 seconds of maximum intensity). Specimens were stored in 100% humidity for 1 week at 37 °C. Push-out test was performed at a crosshead speed of 1 mm/min on 2-mm-thick root slices obtained from coronal to apical direction. Multivariate analysis of variance and Tukey tests were used for statistical analysis of the data (P=.05). Failure modes were examined under the scanning electron microscope. The tested polymerization modes had no significant effect on the bond strength values (P > .05). RealSeal + gutta-percha yielded significantly greater bond strength than RealSeal + Resilon (P < .05). In all groups, the bond strength values decreased significantly from coronal to apical direction (P < .05). Adhesive failure at the sealer-dentin interface was the predominant fracture mode. The exponential photopolymerization mode had no significant advantage over the standard regimen in terms of dentin bond strength.
    Journal of endodontics 06/2011; 37(6):832-5. · 2.95 Impact Factor
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    ABSTRACT: The objective of this study was to investigate the surface porosity of hand-mixed, syringe-mixed and encapsulated set endodontic sealers using image analysis. Eight different root canal sealers (AD Seal/Meta Biomed; AH Plus/Dentsply; MM Seal/Micromega; AH Plus Jet/Dentsply; EndoREZ/Ultradent; Epiphany/Pentron; GuttaFlow/Coltène; RealSeal/Sybron Endo) were prepared in accordance with the manufacturer's recommendations and dispensed into plastic rings (n = 10/group). Following set of the specimens, scanning electron photomicrographs of the sealer surfaces were taken at standard magnification. The area fraction and the minimum-maximum diameters of surface pores were calculated on the micrographs using ImageJ open-source image analysis software. Statistical comparisons were made between the sealers with respect to the area fractions and number of pores (Kruskal-Wallis test, P < .05). The endodontic sealers differed significantly in both the percentage of area fraction and pore count (P < .001). The surface porosity of the methacrylate-based sealers Epiphany and RealSeal were significantly lower than those of resin- and silicone-based sealers. With the exception of AD Seal, hand-mixed sealers displayed significantly higher surface porosity than those of syringe-mixed ones (P < .001). The encapsulated sealer GuttaFlow exhibited the highest surface area fraction of pores. The mixing method influences the surface porosity of set endodontic sealers.
    Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology, and Endodontology 06/2010; 109(6):e117-22. · 1.50 Impact Factor
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    ABSTRACT: This study investigated and compared the root reinforcement potential of 3 different intraorifice barriers (mineral trioxide aggregate [MTA], resin-modified glass ionomer cement [Vitremer], and fiber-reinforced composite [FRC]) placed over root canals obturated with gutta-percha or Resilon. Crowns of 80 extracted human mandibular premolars were sectioned off to obtain 14-mm-long root specimens. After preparation of root canals with nickel-titanium rotary files, the roots were obturated with either the Resilon/Epiphany system or gutta-percha + AH Plus sealer. In both obturation groups, specimens were further subgrouped with respect to the intraorifice barrier material placed after removal of 3-mm coronal portion of the root fillings: (1) MTA, (2) Vitremer, and (3) FRC. The specimens were loaded vertically at 1 mm/min crosshead speed until vertical root fracture occurred. Results were evaluated statistically with two-way analysis of variance and Tukey tests. Fracture resistance of roots was significantly affected by the type of intraorifice barrier (P < .05), but not by the type of obturation system used (P > .05). The use of Vitremer and FRC significantly improved the fracture resistance, whereas MTA did not exhibit any reinforcing effect as an intraorifice barrier.
    Journal of endodontics 06/2010; 36(6):1061-3. · 2.95 Impact Factor
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    ABSTRACT: To investigate the effects of an interfacial fiber-reinforced resin-based material (FRRM) application and different light-curing modes on the bond strength of a thermoplastic synthetic polymer-based root canal filling material (Resilon) to a methacrylate-based sealer (Epiphany). One hundred Resilon disks were prepared and divided into two experimental groups: 1. application of FRRM (EverStick Net) on the Resilon surface, and 2. Resilon alone (control). Following subsequent application of the Epiphany sealer, the specimens were randomly assigned into 3 subgroups according to the curing method employed: 1. chemical curing, 2. quartz-tungsten-halogen (QTH) light, and 3. light-emitting diode (LED). The latter two groups were further subdivided to test the effects of two different polymerization modes for each light-curing unit. Cured specimens were subjected to shear bond strength testing and the failure modes were examined. The data were analyzed with three-way analysis of variance (ANOVA). Regardless of the curing method tested, application of FRRM at the interface significantly increased the bond strength of Resilon to Epiphany (p < 0.001). Bond strength values (MPa) were as follows (mean +/- SD): 1. chemical curing with FRRM= 3.0 +/- 0.4, without FRRM = 1.2 +/- 0.3; 2. QTH: a) standard mode with FRRM = 8.6 +/- 0.6, without FRRM = 5.5 +/- 0.9; b) ramp mode with FRRM = 8.0 +/- 1.0, without FRRM = 5.3 +/- 1.4; 3. LED: a) standard mode with FRRM = 8.8 +/- 1.1, without FRRM = 5.4 +/- 1.0; b) exponential mode with FRRM = 8.5 +/- 1.0, without FRRM = 4.6 +/- 0.6. Although light curing of specimens significantly increased the bond strength of Resilon to Epiphany (p < 0.001), the type of light-curing unit and different curing modes had no significant influence on bond strength (p = 0.852 and p = 0.776, respectively). The highest bond strength values were obtained when the FRRM was used at the interface and the sealer was light cured.
    The journal of adhesive dentistry 09/2009; 11(4):325-30. · 1.44 Impact Factor
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    ABSTRACT: To evaluate the localization and distribution of canal orifices of mandibular second molar teeth in relation to the mesio-distal and bucco-lingual dimensions of coronal tissue. Fifty extracted mandibular second molar teeth were embedded into plaster blocks with their vertical axes aligned perpendicular to the horizontal plane. The teeth were photographed digitally from the occlusal aspect under 12 x magnification. Thereafter, the occlusal halves of crowns were sectioned off to expose the root canal orifices. The teeth were than photographed under the same magnification, after which the pre- and post-sectioning images of each specimen were stacked into a single file. To plot the coordinate of each canal orifice, a 0.5-mm grid analytical plane was mounted digitally on the stack so that the x- and y-axes of the plane were superimposed on the mesiodistal and buccolingual axes (bisectors) of the tooth crowns. Localization and distribution of the coordinates of the canal orifices were evaluated using the chi-square test (P = 0.05). Only one tooth displayed a single root canal orifice, located in the mesiobuccal-distolingual 'centre' of the occlusal surface. The majority of mandibular second molars had three orifices (72%), followed by those with two (16%) and four (10%). The distal canal was located lingual to the centre of the occlusal plane. The distal canal was located lingual to the centre of the occlusal plane of mandibular second molars. The possibility of observing more divergent localizations and orifice numbers should not be overlooked in clinical practice.
    International Endodontic Journal 08/2009; 42(11):973-7. · 2.27 Impact Factor
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    ABSTRACT: The pulp chamber is inevitably exposed to irrigants during endodontic therapy. This study aimed to investigate whether different irrigation regimens would alter the sealing ability of repaired furcal perforations. Pulp chambers of 90 extracted human molars were accessed, after which standardized diamond bur-cut perforations were created in the center of the pulp chamber floor. The canal orifices and the apical end of roots were sealed with acid-etch composite resin. Eighty teeth were randomly divided into 2 groups (n = 40/group) according to the material used for repairing the perforation defects: (1) Mineral trioxide aggregate (MTA), (2) Super-EBA. The remaining teeth (n = 10) served as controls. The specimens were further subgrouped according to the irrigation regimens applied over the repair site (n = 10/group): (a) 5.25% NaOCl, (b) 5.25% NaOCl + EDTA, (c) 5.25% NaOCl + MTAD, and (d) No irrigation. Coronal leakage was measured by the fluid-filtration method at 1 day and 1 week. Fluid conductance was not affected by the type of repair material (P = .964) or time (P = .726), but was affected significantly by the irrigation regimens in the following ranking: (P < .001): NaOCl < or = No Irrigation < NaOCl + MTAD < or = NaOCl + EDTA. The sealing ability of furcal perforations repaired with MTA or Super-EBA were differentially affected by exposure to the tested irrigation regimens.
    Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology, and Endodontology 03/2009; 107(3):e91-5. · 1.50 Impact Factor
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    ABSTRACT: The aim of this study was to compare the bond strength and apical sealing ability of master gutta-percha points with different tapers, as used in conjunction with different root canal sealers. Roots of extracted human maxillary incisors (n = 135) were prepared with 0.06-taper nickel-titanium rotary files to final size 30. The roots were then randomly divided into 3 groups according to the root canal sealer used: 1) AH Plus; 2) Ketac-Endo; and 3) EndoREZ. Each sealer was combined with 1 of the following obturation techniques: 0.02-tapered gutta-percha master cone using lateral condensation, 0.04-tapered gutta-percha master cone using lateral condensation, or 0.06-tapered gutta-percha as a single cone. The bond strength and apical sealing ability were measured with the push-out test and dye penetration test, respectively. The data were statistically analyzed by using Kruskal-Wallis test with Bonferroni correction at P = .05. Both the taper of the gutta-percha point and root canal sealers had significant effects on push-out bond strength (P < .001). According to the microleakage data, AH Plus exhibited significantly lower overall leakage, whereas no difference was found between master cone points (P = .093). The use of matched-taper gutta-percha points in canals prepared with tapered rotary instruments may be advocated to improve bond strength ability of root canal filling material. Furthermore, AH Plus may be preferable to EndoRez and Ketac-Endo in terms of improved sealing and bonding quality of filling material.
    Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology, and Endodontology 01/2009; 107(1):e61-4. · 1.50 Impact Factor