Evaluation of Root Canal Cleaning Efficacy of Selfadjusting Files, Protaper Rotary, and Manual K?Files in Primary Teeth ? An In vitro Comparative Study

Background: The success of pulpectomy depends on complete eradication of microbial load by cleaning and shaping the primary root canals that is difficult to achieve because of anatomical intricacy of primary pulp dentin complex. Numerous instruments were tried, however, they proved to be inadequate. Selfadjusting file (SAF) is a newer file system that facilitates less dentin removal with maximal cleansing of root canals. Aim: To evaluate and compare the in vitro root canal cleaning efficacy with SAF, Protaper Universal, and Hand K?files in primary teeth. Materials and Methods: Sixty extracted primary anterior teeth were randomly divided into three groups by lottery method. Access cavity was prepared, the canals were enlarged up to 20 K file, and an Indian ink was injected into each canal. Then the Group I (n = 20) was treated with SAF, Group II (n = 20) with Rotary Protaper Universal and Group III (n = 20) with Hand K?files and the root canal cleaning efficacy was evaluated based on the amount of Indian ink remaining in the canal walls under stereomicroscopy. Data were analyzed using Kruskal–Wallis one way ANOVA test and post hoc Tuckey test for intragroup and intergroup comparison, respectively. Results: A statistically highly significant difference was observed with SAF (mean = 1.5), Protaper (mean = 2.5), and Hand K?files (mean = 2.9). However, there was no significant difference in root canal cleaning efficacy with Protaper Universal and Hand K?files. Conclusion: The SAFs had shown superior cleaning efficacy compared with rotary Protaper Universal and manual K files.

Estudio comparativo de los tiempos registrados por los instrumentos TruNatomy y ProTaper Next para alcanzar la longitud de trabajo en conductos curvos simulados obturados con GuttaCore / Comparative study of the times recorded by the TruNatomy and ProTaper Next instruments to reach the working length in simulated curved canals filled with GuttaCore

Objetivo: Comparar el tiempo empleado por los instrumen- tos TruNatomy Medium y ProTaper Next X3 para penetrar hasta la longitud de trabajo la masa de obturaciones realizadas con Gut- taCore Primary y sellador en conductos curvos simulados. Materiales y métodos: Se prepararon 20 conductos curvos simulados con instrumentos rotatorios WaveOne Gold Primary y se obturaron con GuttaCore Primary y AH Plus. Las muestras fueron divididas en dos grupos de 10 cada uno. Grupo 1: El material de obturación fue penetrado hasta la lon- gitud de trabajo con instrumentos TruNatomy Medium. Gru- po 2: El material de obturación fue penetrado hasta la longitud de trabajo con instrumentos ProTaper Next X3. Se registraron los tiempos de penetración requeridos para cada grupo y los valores obtenidos fueron analizados mediante la prueba t de Student. Resultados: Los instrumentos ProTaper Next X3 pe- netraron la masa del material de obturación más rápidamente que los instrumentos TruNatomy MediumTM. Las diferencias observadas entre ambos instrumentos fueron estadísticamente significativas (P <0.01). Conclusión: Si bien los instrumentos ProTaper Next X3 y TruNatomy MediumTM penetraron la masa de Gutta- Core Primary de manera eficiente, ProTaper Next X3 penetró hasta la longitud de trabajo más rápidamente (AU)

Aim: Compare the time required by the instruments TruNatomy Medium and ProTaper Next X3 to penetrate up to the working length the mass of fillings made with GuttaCore Primary and sealant in simulated curved canals. Materials and methods: The simulated canals of 20 EndoTraining Blocks were prepared with WaveOne Gold Pri- mary and obturated with GuttaCore Primary and AH Plus. The sample was divided into two groups of 10 each. Group 1: The sealing material was penetrated up to working length with TruNatomy Medium. Group 2: The sealing material was penetrated up to working length with ProTaper Next X3. The penetration time was recorded in each group and the obtained values were statistically analyzed with the Student's t test. Results: ProTaper Next X3 instruments penetrated the sealing material mass faster than TruNatomy Medium. Statis- tically significant differences were observed between the two instruments (P <0.01). Conclusion: While the ProTaper Next X3 and TruNat- omy Medium penetrated the GuttaCore mass to the working length efficiently, the ProTaper Next X3 did it in less time (AU)

Análisis Elemental de las Propiedades Morfológicas, Físicas y Químicas de Dos Instrumentos Rotatorios Protaper Universal

RESUMEN: Los instrumentos rotatorios utilizados en el tratamiento de conductos dentales necesitan cumplir con ciertas características físicas que le confieran un uso correcto, adecuado y seguro para su uso clínico. En el mercado comercial existen una serie de instrumentos importados que dejan en duda la autenticidad de estos debido a sus bajos costos. En este estudio evaluamos física, química y morfológicamente dos kits de instrumentos rotatorios Protaper universal (Dentsply) mediante análisis de MEB, EDX, microdureza y EDS. Uno de los kits (grupo 1) se adquirió directamente de la casa comercial y otro kit importado que a simple vista no parecía cumplir con los estándares de calidad de un correcto empaquetado (grupo 2). En el análisis de MEB se observaron características morfológicas muy diferentes entre ambos kits, el grupo 2 presentó diversas irregularidades en la superficie de las limas, sin embargo, en el EDS no se encontró diferencia alguna. En cuanto al análisis de microdureza se observó una estadística estadísticamente significativa y en el EDS se observaron mayores picos de intensidad en cuanto a la aleación de Ni-Ti en el grupo 2. Estos resultados sugieren que existen instrumentos rotatorios importados que a pesar de su bajo costo pueden presentar ciertas características muy similares a los kits auténticos, sin embargo, física y químicamente pueden resultar en un riesgo para su uso clínico debido a la diferencia entre estos.

ABSTRACT: Rotatory files are instruments used in the treatment of dental canals roots. These instruments need to comply with certain physical characteristics for a correct, adequate and safe use for clinical use. In the commercial market there are a series of imported instruments that cast doubt on their authenticity due to their low costs. In this study we physically, chemically and morphologically evaluated two Protaper universal rotary instrument kits (Dentsply) using SEM, EDX, microhardness and EDS analysis. One of the kits (group 1) was purchased directly from the commercial house and another imported kit that a simple view did not seem to meet the quality standards of a correct packaging (group 2). In the SEM analysis, very different morphological characteristics were observed between both kits, group 2 presented various irregularities on the surface of the files, however, no difference was found in the EDS. Regarding the microhardness analysis, a statistically significant statistic was observed and in the EDS, higher intensity peaks were observed in terms of the Ni-Ti alloy in group 2. These results suggest that there are imported rotary instruments that despite their low cost can present characteristics very similar to authentic kits, however, physically and chemically they can result in a risk for their clinical use due to the difference between them.

In Vitro Evaluation of a Recently Developed Rotary File: AF Rotary / Avaliação in vitro de um arquivo rotativo desenvolvido recentemente: AF Rotary

Objective: Aim of the present study is to evaluate mechanical properties of a newly developed rotary file, AF Rotary (Fanta Dental, Shanghai, China), and to compare these features with a worldwide spread rotary file, Protaper Gold F2 (PTG F2; Dentsply Maillefer, Ballaigues, Switzerland). Material and Methods: 60 AF Rotary 25.06 and 60 PTG F2 were divided in three groups of 20 files each. A group underwent to cyclic fatigue resistance tests, second group underwent to torsional resistance tests, third group underwent to bending tests. The statistical analysis was performed using t student test with significance level set at 95% (p < 0.05). Results: AF Rotary showed significantly higher torsional resistance and cyclic fatigue resistance (p < 0.05) when compared to the PTG F2. AF Rotary also showed significantly lower bending resistance (p < 0.05) when compared to the PTG F2. Conclusion: Therefore, within the limitations of this study, the results show better performances for AF Rotary compared to PTG F2 regarding the cyclic fatigue test, the torsional test and the bending test. Since the PTG F2 is a commonly used and widely investigated instrument it could be possible to state that the AF Rotary exhibits remarkable in vitro performances. (AU)

Objetivo: O objetivo do presente estudo é avaliar as propriedades mecânicas de uma lima rotativa recém-desenvolvida, AF Rotary (Fanta Dental, Shanghai, China), e comparar essas características com uma lima rotativa mundialmente difundida, Protaper Gold F2 (PTG F2; Dentsply Maillefer, Ballaigues, Suíça). Material e Métodos: 60 AF Rotary 25.06 e 60 PTG F2 foram divididos em três grupos de 20 arquivos cada. Um grupo foi submetido a testes de resistência à fadiga cíclica, o segundo grupo foi submetido a testes de resistência à torção, o terceiro grupo foi submetido a testes de flexão. A análise estatística foi realizada por meio do teste t student com nível de significância de 95% (p <0,05). Resultados: AF Rotary apresentou resistência torcional e resistência à fadiga cíclica significativamente maiores (p <0,05) quando comparado ao PTG F2. AF Rotary também apresentou resistência à flexão significativamente menor (p <0,05) quando comparado ao PTG F2. Conclusão: Portanto, dentro das limitações deste estudo, os resultados mostram melhores desempenhos do AF Rotary em relação ao PTG F2 no que diz respeito ao teste de fadiga cíclica, ao teste de torção e ao teste de flexão. Uma vez que o PTG F2 é um instrumento comumente usado e amplamente investigado, pode-se afirmar que o AF Rotary exibe desempenhos in vitro notáveis. (AU)

Effects on the incidence of dentinal microcracks in curved root canal preparation with ProTaper Universal and ProTaper Gold / 口腔疾病防治

Objective@#This study aims to compare the incidence of dentinal microcracks produced by ProTaper Universal (PTU) and ProTaper Gold (PTG) file systems during root canal procedures in different curved canals using a dyeing technique.@*Methods@#Sixty extracted human molars were divided into 3 groups of 20 samples each in terms of root curvature (mild bending group, 10 °-19 °; moderate bending group, 20 °-29 °; severe bending group, 30 °-39 °). Ten samples of each group were then randomly allocated to the PTU and PTG file systems. After preparation, all roots were stained using a dyeing method and sectioned at the most curved plane and 2 mm below and above the most curved plane with a low-speed saw under cold water. A stereomicroscope was used to inspect dentinal microcracks at 60 × magnification, and differences between these three instrument groups were analyzed using the chi-square test.@* Results @# The PTG file system induced significantly fewer dentinal microcracks for total, incomplete and complete cracks (P < 0.05), and the effect was more obvious with increasing canal curvature.@*Conclusion @# With the limitations of this in vitro study, it can be concluded that ProTaper Gold can result in fewer dentinal microcracks than ProTaper Universal.

Evaluación de la resistencia a la flexión de limas rotatorias Protaper Gold, 2Shape, V-Taper Fanta Gold / Evaluation of flexion resistance of Protaper Gold rotary limes, 2Shape, V-Tapert Fanta Gold

Antecedentes: Las limas rotatorias de níquel-titanio con tratamiento termomecánico se desarrollaron para permitir una mayor flexibilidad al instrumentar los conductos radiculares. Los instrumentos permitieron a los operadores tratar las curvaturas de los conductos con mayor facilidad. Los fabricantes están tratando de producir limas que funcionen de manera más eficiente y segura. Conocer las propiedades de las limas comercializadas es especialmente importante porque ayuda a elegir un sistema de lima apropiado. El objetivo de este estudio fue evaluar la flexibilidad de tres limas diferentes de níquel-titanio (NiTi) con tratamiento termomecánico en dos puntos diferentes. Materiales y métodos: Se midió la flexibilidad de tres limas NiTi con tratamiento termomecánico (ProTaper Gold, 2Shape y V-Taper Fanta Gold). Cada lima fue sujetada a 3 mm y 7 mm (n = 10/longitud/lima) y se utilizó una máquina de ensayo universal para doblarla a una fuerza máxima. Todos los datos fueron analizados estadísticamente por análisis de varianza de una vía y prueba de Tukey post hoc (p = 0,05) para determinar cualquier diferencia significativa. Resultados: Se halló diferencias estadísticamente significativas (p < 0,05). En general, V-Taper Fanta Gold fue la más rígida, ProTaper Gold mostró los mayores valores de fuerza y su deformación fue significativamente más flexible. Conclusión: Las limas ProTaper Gold mostraron una mayor flexibilidad en comparación con las otras limas estudiadas. (AU)

Background: Nickel-titanium rotary files with thermomechanical treatment were developed to allow greater flexibility when instrumenting the root canals. The instruments allowed operators to deal with duct curvatures more easily. Manufacturers are trying to produce files that work better efficiently and safely. Knowing the properties of marketed files is especially important in helping you choose an appropriate file system. The objective of this study was to evaluate the flexibility of three different nickel-titanium (NiTi) files with thermomechanical treatment at two different points along the file. Materials and methods: The flexibility of three NiTi files with thermomechanical treatment (Protaper Gold, 2Shape and V-Taper Fanta Gold) was measured. Each file was clamped at 3 mm and 7 mm (n = 10 / length / file) and a universal testing machine was used to bend the files to a maximum strength. All data were statistically analyzed by one-way analysis of variance and post-hoc Tukey test (P = 0.05) to determine any significant differences. Results: There were statistically significant differences (P <0.05). In general, V-Taper Fanta Gold was the most rigid, Protaper Gold showed the highest values of force and deformation was significantly more flexible. Conclusión: Protaper Gold files showed greater flexibility compared to the other files studied. (AU)

Evaluation of Push Out Bond Strength of Two Calcium Silicate Based Cements with Bone Cement in Retrograde Cavities Prepared by Ultrasonic Retro Tips

Introduction: Surgical endodontic treatment comprises ofthorough debridement of pathological periradicular tissue,root end resection followed by a Class I retrograde cavitypreparation and insertion of root end filling material into theprepared cavity. The aim of this study was to evaluate the pushout bond strength of Biodentine, Mineral Trioxide Aggregate(MTA) and Bone Cement used in the retro cavities, preparedwith ultrasonic retro tips.Material and methods: 60 human extracted single rootedteeth were selected and sectioned with a diamond disc (Horico,Germany) to standardize the root length of 15mm. The rootswere instrumented with rotary ProTaper Universal (DentsplyMaillefer) system till size F2. The root canals were obturatedusing gutta percha (Dentsply, Maillefer) and AH Plus sealer(Dentsply, Germany). 3mm of root end resection wasperformed with high speed hand piece under water coolant.3mm deep retro cavities were prepared with ultrasonic stainlesssteel retro tip (Woodpecker). All the specimens were dividedinto 3 groups (n=20) Group I: MTA (ProRoot, Tulsa Dental,USA), Group II Biodentine (Septodont, France), Group IIIBone Cement (Depuy, Johnsons and Johnsons). Each materialwas mixed according to the manufacturers instructions andfilled into the retro cavities. The specimens were sectionedperpendicularly to obtain 1mm thick slices from the apicalportion and subjected to push out bond strength testing underUniversal Testing Machine (Instron).Results: Biodentine showed more push out bond strength thanMTA and Bone Cement. There was no significant differencebetween MTA and Bone Cement groups.Conclusion: Bone Cement can be considered as one of thepotential retro filling material.

Evaluation of Root Dentin Cracks Caused by Three Single File Systems Versus Pro Taper System – An In Vitro Study

Introduction: Biomechanical preparation of root canals isone of the main steps in achieving endodontic success dueto enabling bacterial elimination, removal of debris, andfacilitating obturation. The aim of this study was to comparethe incidence of dentinal cracks observed in the canal wallafter canal instrumentation with 3 single-file systems and theProTaper system (Dentsply Maillefer, Switzerland).Material and Methods: Eighty mandibular premolars withsingle root canal were selected. Teeth were decoronated andmounted in resin blocks with simulated periodontal ligaments.They were divided into 4 experimental groups (n = 20); theninstrumented to the full working length with the ProTaper,OneShape (MicroMega, Besancon, France), Reciproc (VDW,Munich, Germany), and WaveOne Gold (Dentsply Malliefer)was performed. The roots were sectioned perpendicular to thelong axis at 3, 6, and 9 mm from the apex and were observedunder a stereomicroscope. The presence of cracks was noted.The chi-square test was performed to compare the appearanceof cracked roots between the experimental groups.Results: Cracks found after canal instrumentation with theProTaper, OneShape, and Reciproc and WaveOne Goldfiles, were 46.6%, 23.3%, 13.6%, 11.6% respectively. Thedifference between the experimental groups was statisticallysignificant (P < .001).Conclusion: Nickel-titanium instruments cause cracks in rootsurface or in the canal wall; Reciproc and WaveOne Gold filescaused less cracks than the ProTaper and OneShape files.

Evaluation of the Canal Transportation and Centering Ratio at Different Levels of Simulated Curved Canals Prepared by OneShape, Protaper Next, Protaper Gold and TwoShape Nickel Titanium Rotary Files

Background: Preparing and maintaining the original shape in conjunction with its disinfection, exclusive of any procedural error is mandatory in endodontic treatment. Nickel-titanium instruments are much more flexible than conventional stainless steel files combined with superior cutting efficiency. The purposes of this study were to measure and compare the canal transportation, centering ratio at different levels of simulated curved canals of the endodontic training resin blocks, which were instrumented by using of 4 Niti rotary endodontic systems’ Protaper Next, OneShape, Protaper Gold, and TwoShape. Material and Methods: Total 60 resin blocks were randomly divided into 4 groups of 15 canals each; the 1st group was prepared with Protaper Next instruments, the 2nd was prepared with OneShape, the 3rd was prepared with Protaper Gold instruments, and the 4th was prepared with the TwoShape. All were prepared for the size of 25. Removal of material was measured at 5 different levels: at the canal orifice, halfway to the orifice in the straight sections; the beginning of the curve; the crest of the curve; the endpoint. Pre and post-operative photos of the simulated canals were taken in a standardized technique. An assessment of changes has been determined using Photoshop and Digimizer Software. The data were analyzed statistically using Shapiro-Wilk, ANOVA by SPSS software version 21. Results: Regarding the canal transportation, the direction of transportation of rotary NiTi instruments was usually towards the inner aspect at middle parts of the canal, towards the outer aspect of the curve at the apex of the curve and the end of preparation. Conclusion: The TwoShape produced the least amount of canal transportation and preserved the original curvature of the canal more than the other systems evaluated in this study.

Evaluation of debris and smear layer removal with XP-endo finisher: A scanning electron microscopic study

Context: The presence of smear layer and debris can prevent the irrigant and sealer from penetrating the dentinal tubules thereby compromising the seal of the root canal filling. Aim: This study aims to evaluate the efficacy of XP-endo Finisher with ProTaper Next and HyFlex in smear layer and debris removal. Materials and Methods: Thirty-two extracted mandibular premolar teeth were selected and sectioned at the cementoenamel junction. The roots were then randomly divided into 4 groups. In group 1 and 2, canals were instrumented with X2 ProTaper Next (25 0.06 taper). In group 3 and 4, canals were instrumented with HyFlex system (25 0.06 taper). The canals in group 2 and 4 were further finished with XP-endo Finisher. Irrigation was carried out using 3% sodium hypochlorite during instrumentation, and 17% ethylenediaminetetraacetic acid was used as the final rinse. The roots were then split longitudinally. The canal wall was observed under the scanning electron microscope in coronal, middle, and apical thirds at a magnification of ×400 and ×1000 for evaluation of debris and smear layer, respectively. Photomicrographs were taken, and qualitative assessment for debris and smear layer removal was done. Statistical Analysis Used: The results were analyzed using Kruskal–Wallis test and Mann–Whitney U-test. Results: Lower debris and smear layer scores were seen in canal thirds instrumented with ProTaper Next and XP-endo Finisher (P < 0.01). Conclusion: The use of XP-endo Finisher as an adjuvant during shaping and cleaning produced cleaner root canal walls.

A comparison of the effect of different nickel-titanium instruments combined with ultrasonic irrigation on root canal preparation / 口腔疾病防治

Objective @#To compare the removal efficiency and the amounts of apically extruded debris using Twisted File (TF), Twisted File Adaptive (TFA), ProTaper, and ProTaper Next combined with ultrasonic irrigation and to provide an experimental basis for the selection of root canal instrumentation in the clinic.@*Methods@#Forty mandibular premolars were randomly divided into 4 groups (n=10 teeth per group). The canals were cut using a Twisted File, Twisted File Adaptive, ProTaper, or ProTaper Next nickel-titanium instrument. The canals were irrigated with ultrasonic irrigation. The apically extruded debris were collected in preweighted Eppendorf tubes. The amount of dental tissue removed and extruded debris were assessed with an electronic balance.@*Results @#The amount of tooth tissue removed in groups A, B, C and D was 20.5 ± 2.0 mg, 17.8 ± 4.2 mg, 20.8 ± 3.9 mg and 16.5 ± 2.2 mg, respectively. Combined with ultrasonic irrigation, the Twisted File and ProTaper had a better removal efficiency than the ProTaper Next(P < 0.05). There was no significant difference in the amount of extruded debris (χ2=4.057, P=0.255) among four groups.@*Conclusion@#The Twisted File and ProTaper had a better removal efficiency than the ProTaper Next combined with ultrasonic irrigation. There was no significant difference in the amount of extruded debris using four Nickel-titanium instruments combined with ultrasonic irrigation.

Comparison of the formation ability of two types of machine-made nickel-titanium instruments in simulated curved root canals / 口腔疾病防治

Objective@#To compare ProTaper Universal (PU) and M3-L instruments in preparing curved root canals and to provide a reference for clinical applications.@*Methods@#Twenty resin-simulated curved single root canals were randomly divided into two groups. Root canal preparation was performed with a PU nickel-titanium file or an M3-L nickel-titanium file. Root canal preparation time, root canal length before and after preparation and root canal deviation were recorded.@*Results@#In the M3-L group, the displacement measured at the 4th to 7th sites was less than that in the PU group (P < 0.05), but there was no significant difference between the other two groups (P > 0.05); The length of the root canal before and after root canal preparation in the M3-L group was （14.90 ± 1.92）mm and （14.57 ± 1.13）mm, respectively, and the difference between the two groups was not statistically significant (t=3.18, P=0.058). The root canal length before and after root canal preparation in the PU group was（14.53 ± 1.53）mm and （14.28 ± 1.39）mm, respectively. The difference between the two groups was not statistically significant（t=2.12,P=0.124）; The average preparation time of the M3-L group [（110.15 ± 10.43）s] was less than that in the PU group [（330.48 ± 12.62）s] (P < 0.05).@*Conclusion @#The M3-L nickel-titanium file has better central positioning ability and is less time-consuming than the PU nickel-titanium file in root canal bending preparation.

Cyclic fatigue, bending resistance, and surface roughness of ProTaper Gold and EdgeEvolve files in canals with single- and double-curvature

OBJECTIVES: The purpose of this study was to evaluate the cyclic fatigue, bending resistance, and surface roughness of EdgeEvolve (EdgeEndo) and ProTaper Gold (Dentsply Tulsa Dental Specialties) nickel-titanium (NiTi) rotary files. MATERIALS AND METHODS: The instruments (n = 15/each) were tested for cyclic fatigue in single- (60° curvature, 5-mm radius) and double-curved (coronal curvature 60°, 5-mm radius, and apical curvature of 30° and 2-mm radius) artificial canals. The number of cycles to fracture was calculated. The bending resistance of both files were tested using a universal testing machine where the files were bent until reach 45°. Scanning electron microscopy and x-ray energy-dispersive spectrometric analysis were used for imaging the fractured segments, while the atomic force microscope was used to quantify the surface roughness average (Ra). RESULTS: EdgeEvolve files exhibited higher cyclic fatigue resistance than ProTaper Gold files in single- and double-curved canals (p 0.05). EdgeEvolve files showed significantly lower Ra values than ProTaper Gold files (p < 0.05). CONCLUSIONS: Within the limitation of this study, EdgeEvolve files exhibited significantly higher cyclic fatigue resistance than ProTaper Gold files in both single- and double-curved canals.

Eficacia de dos sistemas mecanizados para la desobturación de conductos radiculares curvos obturados con GuttaCore / Efficacy of two engine-driven systems for the removal of GuttaCore fillings from curved root canals

Objetivo: Comparar ex vivo la eficacia del instrumento WaveOne Gold Primary con la del sistema ProTaper Retratamiento para la remoción del material de obturación en conductos mesiales de molares inferiores obturados con GuttaCore y sellador. Materiales y métodos: Se seleccionaron raíces mesiales de 15 molares inferiores humanos extraídos con dos conductos radiculares cada una, forámenes independientes y curvaturas de entre 20o y 40o. Los conductos se prepararon con el sistema WaveOne Gold hasta una longitud de trabajo prefijada y hasta el instrumento Primary. La irrigación fue realizada con NaClO al 2,5%. Todos los conductos fueron obturados mediante GuttaCore empleando el obturador Primary y el sellador AH Plus con el agregado de una gota de azul de metileno al 1%. Los 30 conductos (15 mesio-vestibulares y 15 mesio-linguales) fueron divididos al azar en dos grupos de 15 (n=15) conductos cada uno. Los del grupo 1 fueron desobturados con el instrumento de movimiento recíproco WaveOne Gold Primary; los del grupo 2, con el sistema rotatorio ProTaper Retratamiento. Las muestras fueron incluidas en bloques de resina acrílica y se realizaron secciones transversales de 1 mm de espesor a nivel de 1,5, 3 y 9 mm de la longitud de trabajo con micrótomo para tejidos duros. Luego se observaron con un microscopio óptico bajo luz reflejada y se fotografiaron con una cámara digital. Las imágenes se analizaron mediante un programa informático. En cada grupo y en cada uno de los niveles prefijados, los resultados fueron expresados como la diferencia entre el área cubierta por restos de gutapercha/sellador y el área total perimetral del conducto radicular, y analizados mediante ANOVA y la prueba de Tukey, con un nivel de significación de P<0,05. Resultados: Se observaron remanentes del material de obturación en todos los niveles de ambos grupos. No hubo diferencias significativas (P>0,05) entre grupos. Las diferencias observadas entre los niveles prefijados fueron significativas (P<0,05), especialmente cuando se compararon los resultados obtenidos a 1,5 y 9 mm de la longitud de trabajo. Conclusiones: El empleo de WaveOne Gold Primary o ProTaper Retratamiento no permitió remover completamente el material de obturación en conductos mesiales de molares inferiores obturados con GuttaCore y AH Plus (AU)

Comparative Evaluation of Canal Centering Ability between Protaper Rotary and Self Adjusting File in Oval Shaped Canals – A Cone Beam Computed Tomographic Analysis

Background: Self Adjusting Files have been introduced to overcome the disadvantage of protaper rotary files, especially for oval root canal centering. Aims and Objectives: To evaluate the canal centering ability between rotary protaper and self adjusting file in oval shaped canals using cone beam computed tomography. Methods:The study was carried out on 20 single rooted mandibular premolars. To compare the canal centering ability produced by different techniques, pre-instrumentation, post-instrumentation, cross section images of specimen at 3, 6 and 9 mm from the apex were obtained from the 3D CBCT images of each individual group. The images captured digitally using Image Tools Software were compared. Results: Inter group comparison of mean ratio of both the groups at 3, 6 and 9 mm after preparation of canal showed statistically significant difference between both the groups (p<0.05). Intra group comparison of mean ratio of both the groups at 3, 6 and 9 mm after preparation of canal showed that the difference between both the groups was not statistically significant (p>0.05).Conclusion: The canal centering ability of self adjusting file was efficient than protaper rotary files.

Comparison Of Instrumentation Time And Cleaning Efficacy Of Manual K–File, Rotary Protaper Universal And Rotary Protaper Next In Primary Anterior Teeth: An In–Vitro Study

Introduction: Pulpectomy of primary teeth with severe pulpal involvement is one of the most important concerns in Pediatric Dentistry.Root canal instrumentation is performed with files, reamers, sonic instruments and recently with rotary instruments. Although manual instrumentation is widely used in primary teeth, but they have limitations.The development of nickel titanium alloys and the possibility of changing the traditional design and taper have allowed use of rotary instruments in endodontic treatment. A new generation of NiTi rotary files has been introduced as the Protaper Next. Aim : The present study aimed to compare the instrumentation time and cleaning efficacy of Protaper Next with rotary Protaper Universal system and manual K file in pediatric endodontics. Materials and Methods: An in-vitro experimental study was conducted by injecting Indian ink in a total sample of 60 human single rooted primary anterior teeth. The teeth were randomly divided into three experimental groups, including K-file,ProTaper Universal, Protaper Next and one control group. The root canals were prepared using one of the three file system followed by clearing the teeth with different demineralising solutions.A chronometer was used to calculate the instrumentation time in each root canal and scores were analysed by a steremicroscope. Data analyses were performed using version 21.0 of Statistical Package for Social Sciences. Results: In the coronal third of root canals cleaning efficacy of K Files and ProTaper Next showed almost similar score.In the middle third of root canals cleaning efficacy scores in two file systems were significantly lower than K files . In the apical third ProTaper Next showed better cleaning efficacy compared to K files and ProTaper Universal Files systems. Difference between the different groups was statistically significant P=0.000(<0.001). Conclusion: This study showed that the use of Ni-Ti rotary instruments in the pulpectomy of primary anterior teeth represents a promising technique in pediatric patients, thus instrumentation is feasible, offeringtime-saving advantages in root canal preparation

AN in vitro study of 4 instruments in the preparation of curved root canals / 实用口腔医学杂志

Objective: To compare ProTaper Universal(PU),ProTaper Next(PN),WaveOne(WO) and M3 in the preparation of simulated curved canals. Methods: 40 simulated root canals were made from translucent resin and randomly divided into 4 groups(n = 10),the canals were prepared by PU,PN,WO and M3 respectively. The efficacy of canal preparation was analyzed. The pre-instrumentation and post-instrumentation images were recorded and the assessment of the canal shape was completed with Photoshop cs6 and Image Pro Plus6. 0. The apical transportation indexes and the amounts of apically extruded debris were measured. Results: WO was the most time-saving in mean working time(P ＜ 0. 05). PN and M3 took less time than PU in shaping the canals at the most levels(P ＜ 0. 05; PN vs M3,P＞ 0. 05). The amounts of apically extruded debris by PN was less than by PU,WO and M3(P ＜ 0. 05). The apical transportation by PN and M3 was less than that by PU and WO(P ＜ 0. 05). Conclusion: WaveOne is the most time-saving in shaping root canals. ProTaper Next and M3 are more effective and time-saving than ProTaper Universal in shaping root canals. ProTaper Next and M3 are comparable for optimally enlarge root canal.

Root canal volume change and transportation by Vortex Blue, ProTaper Next, and ProTaper Universal in curved root canals

OBJECTIVES: The aim of this study was to compare root canal volume change and canal transportation by Vortex Blue (VB; Dentsply Tulsa Dental Specialties), ProTaper Next (PTN; Dentsply Maillefer), and ProTaper Universal (PTU; Dentsply Maillefer) nickel-titanium rotary files in curved root canals. MATERIALS AND METHODS: Thirty canals with 20°–45° of curvature from extracted human molars were used. Root canal instrumentation was performed with VB, PTN, and PTU files up to #30.06, X3, and F3, respectively. Changes in root canal volume before and after the instrumentation, and the amount and direction of canal transportation at 1, 3, and 5 mm from the root apex were measured by using micro-computed tomography. Data of canal volume change were statistically analyzed using one-way analysis of variance and Tukey test, while data of amount and direction of transportation were analyzed using Kruskal-Wallis and Mann-Whitney U test. RESULTS: There were no significant differences among 3 groups in terms of canal volume change (p > 0.05). For the amount of transportation, PTN showed significantly less transportation than PTU at 3 mm level (p = 0.005). VB files showed no significant difference in canal transportation at all 3 levels with either PTN or PTU files. Also, VB files showed unique inward transportation tendency in the apical area. CONCLUSIONS: Other than PTN produced less amount of transportation than PTU at 3 mm level, all 3 file systems showed similar level of canal volume change and transportation, and VB file system could prepare the curved canals without significant shaping errors.

Evaluación cualitativa pos instrumentación ex vivo comparando tres técnicas: escalonada con retroceso programado-oregón modificada por la FOB-técnica rotatoria protaper / Ex vivo post-instrumentation qualitative evaluationcomparing three techniques: step back - oregonmodified by F O B – protaper rotary technique

El objetivo de este trabajo fue evaluar cualitativamente las regularidades de los conductos radiculares preparados con diferentes técnicas: técnica escalonada de retroceso programado, técnica Oregón modificada por la F.O.B. y técnica rotatoria Protaper. Fueron utilizados 30 conductos radiculares ex vivo de dientes unirradiculares de un único conducto. Los conductos fueron instrumentados de la siguiente manera: G1 (n=10) con la técnica escalonada de retroceso programado, G2 (n=10) con Oregon modificada por la F.O.B y G3 (n=10) con técnica rotatoria Protaper. Una vez acabada la instrumentación el material de impresión fue inyectado en el conducto radicular; después del fraguado del material de impresión los dientes fueron descalcificados para obtener los moldes de los conductos que fueron fotografiados con aumento 20x con microscopio digital Dino Lite plus para analizar la uniformidad de la instrumentación por tercios por las tres diferentes técnicas, clasificándolas en: CBI (conducto bien instrumentado), CRI (conducto regularmente instrumentado), CPI (conducto pobremente instrumentado). Los resultados mostraron predominancia de CBI para la técnica Protaper en los tercios medio y apical; en el tercio cervical para las tres técnicas y el tercio apical para la técnica Oregon modificada, siendo los peores resultados para la técnica escalonada de retroceso programado y Oregon modificada en el tercio medio, tercio apical en la Escalonada de Retroceso Programado. No hubo diferencias estadísticamente significativas en la efectividad de las técnicas escalonada de retroceso programado, Oregon modificada y Protaper cuando fueron analizados cualitativamente los moldes de los tercios. Concluimos que las técnicas coronoapicales resultaron en una instrumentación más uniforme y de mejor calidad que la técnica escalonada.

The aim of this study was to evaluate qualitatively the regularities of root canalsprepared with different techniques: Step Back – Oregon modified by F.O.B andProtaper. Thirty ex vivo root canals of single-rooted teeth with a single root canal wereused. The canals were instrumented as follows: G1 (n=10) Step Back, G2 (n=10)Oregon modified by FOB and G3 (n=10) Protaper tecniques. Once instrumentation finished, impression material was injected into the root canal. After casting of theimpression material, the teeth were decalcified to obtain molds of the root canals thatwere photographed with 20x magnification using a digital Dino Lite plus microscope toanalyze the uniformity of the instrumentation on the thirds using the three techniquesthat were classified into: WIC (well instrumented canal), RIC (regularly instrumentedcanal) and PIC (poorly instrumented canal). The results shown predominance of WICfor the Protaper technique in the middle and apical thirds, in the apical third for thethree techniques and the apical third for the modified Oregon technique, being theworst results for the Step Back and Oregon techniques in the middle third, and for theStep Back in the apical third. There were no statistically significant differences in theeffectiveness of the Step Back, modified Oregon and Protaper techniques when thethirds molds were analyzed qualitatively. We conclude that the crown-apicaltechniques resulted in more uniform and better quality instrumentation than the StepBack technique.

Protaper Next: la evolución / Protaper Next: the evolution

El objetivo del presente artículo es describir y analizar las características técnicas y de diseño del sistema Protaper Next. Este sistema aparece en el mercado odontológico en el año 2012, transformándose en el sucesor del Protaper Universal. Una de sus principales modificaciones consiste en la disminución del número de instrumentos requeridos para realizar el tratamiento endodóntico.

The objective of this article is to describe and analyze the technical and design characteristics of the Protaper Next System.This system appeared at the dental market in 2012 becoming the successor of Protaper Universal.One of its main modifications is the minor numbers of instruments required for doing an endodontic treatment.