How do reused glide path files affect the cyclic fatigue resistance? / ¿Cómo afecta la reutilización de limas tipo glide path su resistencia a la fatiga cíclica?

ABSTRACT: The aim of this study was to compare the cyclic fatigue resistance (CFR) of PathFile (Dentsply Sirona, Ballaigues, Switzerland) and ScoutRace (FKG Dentaire, La Chaux-de-Fonds, Switzerland) glide path files which were either new or previously used. Forty PathFile (PF) 19/.02 and 40 ScoutRace (SR) 20/.02 instruments were used for this study. Half of the files in each group were used (PF-U and SR-U) in the 3D demo tooth models (FKG Dentaire, La Chaux-de-Fonds, Switzerland) for creating glide paths, while the other half was new (PF-N and SR-N) and directly subjected to the cyclic fatigue test. The new and used files (n=80) were rotated in the cyclic fatigue test device with an artificial stainless-steel canal (60° curvature, 5 mm radius 1.5 mm width and 3.0 mm depth) under the continuous irrigation with distilled water at 37°C until fracture occurred. Time to fracture was recorded and the Weibull reliability analysis was performed. Data were statistically analysed. Conformity to normal distribution was examined using the Shapiro-Wilk test. A paired two-sample t-test was used to compare the TTF values according to the time within the groups. The new instruments (PF-N and SR-N) showed better CFR than the used groups (PF-U and SR-U) (P SR-N>PF-U>SR-U. Reuse of both glide path instruments reduced the time to fracture and the cyclic fatigue resistance of the files.

RESUMEN: El objetivo de este estudio fue comparar la resistencia a la fatiga cíclica (CFR en inglés) de las limas PathFile (Dentsply Sirona, Ballaigues, Suiza) y ScoutRace (FKG Dentaire, La Chaux-de-Fonds, Suiza) de tipo glide path, nuevas o ya previamente utilizadas. Para este estudio se utilizaron 40 instrumentos PathFile (PF) 19/.02 y 40 ScoutRace (SR) 20/.02. La mitad de las limas de cada grupo se utilizaron (PF-U y SR-U) en los modelos dentales de demostración 3D (FKG Dentaire, La Chaux-de- Fonds, Suiza) para crear trayectorias de deslizamiento, mientras que la otra mitad se utilizaron nuevas directamente a la prueba de fatiga cíclica (PF-N y SR-N). Las limas nuevas y usadas (n=80) se hicieron girar en el dispositivo de prueba de fatiga cíclica con un canal artificial de acero inoxidable (curvatura de 60°, radio de 5mm, anchura de 1,5mm y profundidad de 3,0mm) bajo irrigación continua con agua destilada a 37°C hasta que se produjo la fractura. Se registró el tiempo hasta la fractura y se realizó el análisis de fiabilidad de Weibull. Los datos se analizaron estadísticamente. La conformidad con la distribución normal se examinó mediante la prueba de Shapiro- Wilk. Se utilizó una prueba t de dos muestras pareadas para comparar los valores de TTF según el tiempo dentro de los grupos. Los instrumentos nuevos (PF-N y SR- N) mostraron una mejor CFR que los grupos previamente utilizados (PF-U y SR-U) (p SR-N >PF-U >SR-U. La reutilización de ambos instrumentos tipo glide path redujo el tiempo hasta la fractura y la resistencia a la fatiga cíclica de las limas.

Effect of glide path preparation with PathFile and ProGlider on the cyclic fatigue resistance of WaveOne nickel-titanium files

OBJECTIVES: The aim of this study was to investigate the effect of glide path preparation with PathFile and ProGlider nickel-titanium (NiTi) files on the cyclic fatigue resistance of WaveOne NiTi files. MATERIALS AND METHODS: Forty-four WaveOne Primary files were used and divided into four groups (n = 11). In the first group (0 WaveOne), the WaveOne Primary files served as a control group and were not used on acrylic blocks. In the 1 WaveOne Group, acrylic blocks were prepared using only WaveOne Primary files, and in the PF+WaveOne group and PG+WaveOne groups, acrylic blocks were first prepared with PathFile or ProGlider NiTi files, respectively, followed by the use of WaveOne Primary files. All the WaveOne Primary files were then subjected to cyclic fatigue testing. The number of cycles to failure was calculated and the data were statistically analyzed using one-way analysis of variance (ANOVA) and the Tukey honest significant difference multiple-comparison test at a 5% significance level. RESULTS: The highest number of cycles to failure was found in the control group, and the lowest numbers were found in the 1 WaveOne group and the PF+WaveOne group. Significant differences were found among the 1 WaveOne, PF+WaveOne, and control groups (p 0.05). CONCLUSION: Glide path preparation with NiTi rotary files did not affect the cyclic fatigue resistance of WaveOne Primary files used on acrylic blocks.

Permeabilización del Canal Radicular y Transporte Apical: Comparación de Tres Sistemas / Root Canal Glide Path and Apical Transportation: Three System Comparison

La mantención de la anatomía original del canal radicular incide directamente en el éxito del tratamiento endodóntico. Para ello, los sistemas rotatorios de instrumentación requieren de canales radiculares permeables. Existen distintas limas y sistemas para la permeabilización o glide path como las limas tipo K manuales de acero inoxidable y los sistemas de NiTi rotatorios PathFile y ProGlider (Dentsply, Maillefer). Así, el objetivo de esta investigación fue comparar la capacidad de distintos sistemas de permeabilización para mantener la anatomía radicular sin producir transporte apical en canales mesiales de molares inferiores humanos extraídos. Se realizó un estudio cuantitativo experimental cuya muestra estuvo conformada por 36 canales mesiales de molares mandibulares humanos extraídos. Las muestras fueron divididas aleatoriamente en tres grupos conformados por 12 canales, cada uno de los cuales fueron sometidos a distintos sistemas de permeabilización (Lima K, PathFile y ProGlider). Las muestras fueron fotografiadas antes y después de la permeabilización utilizando un microscopio con magnificación 30X. Se cuantificó el desplazamiento del canal radicular en sentido mesio - distal y buco - lingual posterior a la permeabilización. Para el análisis de los datos se utilizó el paquete estadístico InfoStat/L y se aplicó la prueba de ANOVA / Tukey. Se observó que el sistema PathFile produce mayor transporte del canal radicular en su tercio apical en la dirección mesio-distal (p=0,77) y el sistema ProGlider en la dirección buco-lingual (p=0,57). Sin embargo, estas diferencias no fueron significativas. En conclusión, los sistemas de permeabilización analizados no presentaron diferencias en cuanto a su capacidad para mantener la anatomía sin producir transporte apical.

Preservation of the original root canal anatomy has a direct influence on the success of an endodontic treatment. In order to achieve this, rotary instrumentation systems require permeable root canals. Different files and systems are used for the establishment of a glide path such as manual stainless steel K files and NiTi rotatory systems like PathFile and ProGlider (Dentsply, Maillefer). Thus, the objective of this research was to compare the ability of different systems to create a glide path and maintain root canal anatomy without producing apical transportation in mesial root canals of extracted human lower molars. A quantitative experimental study was performed with a sample of 36 mesial root canals of extracted human mandibular molars. The samples were randomly divided into three groups consisting of 12 root canals each, which were subjected to different glide path systems (K-Files, PathFile and ProGlider). Samples were photographed before and after creating glide path using a microscope with 30X magnification. The displacement of the root canal in a mesio - distal and bucco - lingual direction was quantified after creating glide path. Data was analyzed using the statistical package InfoStat / L and the ANOVA / Tukey test was applied. The PathFile system produced greater transport of the root canal in its apical third in the mesio-distal direction (p = 0.77) and the ProGlider system in the bucco-lingual direction (p = 0.57). However, these differences were not significant. In conclusion, the glide path systems analyzed do not present any differences in their ability to maintain the anatomy without producing apical transportation.

Shaping ability of Pathfile and WaveOne in simulated root canals / 口腔疾病防治

Objective @# This study aims to evaluate the shaping capability of Pathfile and WaveOne in simulated root canals. @*Methods@#A total of 20 simulated resin blocks were divided randomly into two groups, group W prepared with WaveOne alone. Group PW prepared with WaveOne and Pathfile. Preparation time and number of separated instruments were measured respectively. Pre-and post-operative images were obtained with a scanner and superimposed through Photoshop and ImageJ2X. The changes in canal bending curvature and material removal from the inner and outer canal walls at 10 points beginning at 1mm from the end point of the canal were measured with ImageJ2X. Centering capability was determined accordingly by comparing and analyzing the material removal from the inner and outer canal walls.@*Results @# Two groups have no occurrence of instrument separation, no statics significance in root canal preparation and the changes of root canal working length differences (P > 0.05). But at position of root canal point 4 to 5 mm, the misalignment of group W were 0.085 ± 0.05 mm and -0.312 ± 0.068 mm, the misalignment of group PW were -0.071 ± 0.042 mm, -0.26 ± 0.103 mm (P < 0.05).@*Conclusion@#Conclusion

Clinical Evaluation of the Combined Application of Pathfile and Mtwo in Preparing Curved Root Canals / 华中科技大学学报(医学版)

Objective To evaluate the clinical efficacy of combined use of Pathfile and Mtwo in the preparation of curved root canals.Methods This study enrolled a total of 90 teeth(313 root canals)that need root canal therapy because of pulpitis or apical periodontitis from December 2013 to February 2014.All root canals were randomly divided into three groups.In group A,both Pathfile and Mtwo NiTi files were used in root canal preparation.In group B,Pathfile and ProTaper were used.ProTaper was employed alone in root canal preparation in group C.The high temperature thermaplasticized inj ectable ver-tical condensation technique was applied in all the three groups.The time of root canal preparation,the number of separated de-vices,root canal transportation and the quality of root canal filling were obtained and compared among the 3 groups.Results In group A,the time of root canal preparation was shortest,(6.01±1.12)min ;there were no instrument separation and ledge for-mation,and the filling rate was highest in group A.The differences were significantly noted in these indexes between group A and groups B,C.Conclusion Combined use of Pathfile and Mtwo for preparation of curved root canals is fast and safe,and the root canal filling is satisfactory.This method is suitable for clinical application.

Uso de rotatórios pathfile e mtwo como acesso inicial no preparo endodôntico: comparação com limas manuais em canais curvos / Use of rotation and pathfile MTwo as initial access in endodontic treatment: a comparison with hand files in curved canals

Introdução: Instrumentos rotatórios em níquel-titânio reduzem erros processuais e o tempo requerido para finalização do preparo do canal radicular. O objetivo deste estudo foi avaliar as ocorrências de transporte apical e aberrações nos canais produzidas com diferentes instrumentos utilizados para a criação de trajetória-guia (“glide path”) no preparo de canais curvos: limas manuais K e limas rotatórias em níquel-titânio PathFile e Mtwo. Material e Métodos: Os canais mesiais de 45 primeiros e segundos molares inferiores (com ângulos de curvatura entre 25 e 35 graus) foram selecionados para o estudo. As amostras foram divididas aleatoriamente em três grupos de 15 canais cada e o preparo foi realizado por um endodontista utilizando limas manuais de aço inoxidável tipo K #10-15-20, conicidade 0,02 (grupo M), instrumentos rotatórios PathFile #13-16-19, conicidade 0,02 (grupo PF) e instrumentos rotatórios Mtwo #10/04- #15/05- #20/06 (grupo MT). Foi utilizada a técnica da dupla radiografia digital, pré e pós-instrumentação, para avaliar se ocorreu transporte apical e/ou aberrações na morfologia dos canais. Por meio de uma análise computadorizada e com o auxílio de magnificação, as imagens inicial e final do eixo central foram comparadas por meio de sua sobreposição. Os espécimes foram analisados por 3 avaliadores, cuja calibração foi checada por meio do teste de concordância de Kendall. Resultados: Não ocorreu transporte apical nem aberração na morfologia do canal em 100% dos dentes, portanto nenhuma análise estatística foi realizada. Conclusão: Tanto os instrumentos rotatórios PathFile e Mtwo quanto os instrumentos manuais utilizados para a criação de trajetória-guia não exerceram influência sobre a ocorrência de transporte apical nem promoveram aberrações na morfologia dos canais .

Introduction: Nickel-titanium rotary instruments reduce procedural errors and the time required to finish root canal preparation.The goal of this study was to evaluate the occurrences of apical transportation and canal aberrations produced with different instruments used to create a glide path in the preparation of curved root canals, namely: manual K files and PathFile and Mtwo nickel-titanium rotary files. Methods:The mesial canals of 45 mandibular first and second molars (with curvature angles between 25 and 35 degrees) were selected for this study. The specimens were divided randomly into three groups with 15 canals each, and canal preparation was performed by an endodontist using #10-15-20 K-type stainless steel manual files (Group M), #13-16-19 PathFile rotary instruments (Group PF), and #10-15-20 Mtwo rotary instruments (Group MT). The double digital radiograph technique was used, pre- and post-instrumentation, to assess whether apical transportation and/or aberration in root canal morphology occurred. The initial and final images of the central axis of the canals were compared by superimposition through computerized analysis and with the aid of magnification. The specimens were analyzed by 3 evaluators, whose calibration was checked using the Kendall agreement test. Results: No apical transportation or aberration in root canal morphology occurred in any of the teeth; therefore, no statistical analysis was conducted. Conclusion: Neither the manual instruments nor the PathFile or Mtwo rotary instruments used to create a glide path had any influence on the occurrence of apical transportation or produced any canal aberration