Influencia de la Experiencia del Operador en la Conformación de Canales Radiculares Simulados Utilizando Waveone Gold

Evaluar la influencia del operador sobre el transporte apical y centrado de la instrumentación endodóntica utilizando WaveOne Gold en canales radiculares simulados de resina acrílica. Se asignaron 32 canales simulados de resina acrílica a dos grupos (n = 16). El grupo 1 conformado por estudiantes inexpertos y el grupo 2 por especialistas en el área de endodoncia. Estos canales se instrumentaron hasta un tamaño apical de 25/07 con lima Primary WaveOne Gold. Para evaluar el transporte apical y el centrado de la instrumentación se utilizaron imágenes fotográficas que fueron analizadas mediante los software de edición de imagen Photoshop e Image J. Además fue registrada la incidencia de fractura de instrumentos. Los datos fueron registrados mediante un formulario Google Forms y analizados mediante el software estadístico R. Se evaluó la normalidad de los dato s mediante el test Shapiro-Wilk y para establecer diferencias entre los grupos se realizó la prueba t. El nivel de significancia estadística fue establecido en p < 0,05. La mayor diferencia al evaluar el centrado se evidenció a nivel de los 6 mm y en cuanto al transporte apical la mayor discrepancia fue a nivel de 1 mm. Sin embargo, no se observaron diferencias significativas entre ambos grupos e n ninguno de los puntos evaluados. Se reportó una baja incidencia de fractura de instrumentos. La experiencia del operador no influye en la conformación del canal radicular simulado al evaluar centrado y transporte apical al utilizar limas WaveOne Gold.

To evaluate root canal transportation and centering ability as influenced by operator experience using WaveOne Gold files in simulated acrylic resin root canals. Thirty-two simulated acrylic resin canals were distributed to two groups (n = 16). Group 1 is made up of inexperienced students, and group 2 by specialists in the field of endodontics. These canals were shaped to an apical size of 07/25 with the Primary WaveOne Gold file. Photographic images were used to evaluate apical transport and centering of the instrumentation, which was analyzed using Photoshop and Image J image editing software. File separation was also recorded. The data were recorded using Google Forms and analyzed using the R statistical program. The normality of the data was evaluated using the Shapiro-Wilk test, and the t-test was performed to establish differences between the groups. The level of statistical significance was established as p <0.05. The normality of the data was evaluated using the Shapiro-Wilk test. Then statistical significance was analyzed using the T-test. The most remarkable difference when evaluating centering was evident at the 6 mm level. In terms of apical transport, the major discrepancy was at the 1 mm level. However, no significant differences were observed between both groups in any of the points evaluated. A low incidence of instrument fracture was reported. According to our results, the operator's experience does not influence shaping in simulated root canals in terms of centering ability and apical transportation when using WaveOne Gold files.

Evaluation of glide path preparation and shaping ability of two nickel-titanium engine driven systems in moderate curved root canals / 上海交通大学学报（医学版）

Objective:To evaluate the clinical application effect of two nickel-titanium engine driven systems on moderate curved root canals. Methods:Ninety mesial root canals with moderate curvature of extracted human first mandibular permanent molar were randomly divided into three groups: M3 PRO Group, MTwo group and K group. The glide path was firstly prepared by using #10/04 file in M3 PRO group and MTwo group and #10 file in K group respectively.Then the preparation of root canals up to #25 was performed according to the instruction manual in each different group using standardized technique. All data including time required in glide path preparation, shaping preparation, total root canals preparation and changes of working length in root canal were recorded and analyzed statistically by using Analysis of Variance (ANOVA) and LSD-t tests (P<0.05). Results:Root canal glide path preparation time: MTwo group showed significantly less preparation time while M3 PRO group exhibited significantly the longest preparation time. There was significant difference between MTwo group and M3 PRO group (P=0.001). Root canal shaping preparation time: M3 PRO group showed significantly less preparation time while K group exhibited significantly the longest preparation time. Both MTwo group and M3 PRO group showed significantly less preparation time than K group (P=0.004, P=0.001), but there was no significant difference between MTwo group and M3 PRO group (P=0.573). Total root canal preparation time: MTwo group showed the shortest time while K group exhibited the longest time. There were significant differences between MTwo group, M3 PRO group and K group (P=0.004, P=0.033), but no significant difference between MTwo group and M3 PRO group (P=0.451). Changes of root canal working length: There were significant differences among the three groups (P=0.037, P=0.037, P=0.000). M3 PRO group showed a minimal change while K group exhibited significant changes. Conclusion:MTwo nickel-titanium engine driven system with #10/04 file preform a high efficiency in glide path preparation, whilst M3 PRO nickel-titanium engine driven system show less changes in working length. Under the circumstances where the total time required for root canal preparation is not significant, M3 PRO nickel-titanium engine driven system is more suitable for root canal preparation in moderate curved root canals.

Comparison of the shaping ability of different nickel-titanium instruments in simulated root canals in resin / 口腔疾病防治

Objective @#To compare the shaping ability of 3 different nickel (Ni)-titanium (Ti) systems in simulated root canals in resin and to provide a reference for clinicians.@*Methods@#Forty-eight resin blocks were prepared using the F360 (Komet, Brasseler GmbH & Co., Lemgo, Germany) (Group 1), F6 SkyTaper (20/06) (Komet, Brasseler GmbH & Co., Lemgo, Germany) (Group 2), F6 SkyTaper (25/06) (Komet, Brasseler GmbH & Co., Lemgo, Germany) (Group 3) and Reciproc R25 systems (VDW, Munich, Germany) (Group 4) (n=12 canals/group). The images taken before and after preparation were superimposed and analyzed by Adobe Photoshop v7.0. The amount of resin removed by each system was measured, and the centering ability was assessed. The data were statistically analyzed using SPSS 20.0.@*Results @#At the 1 mm point, the transportation in Group 4 [(0.10 ± 0.03) mm] was significantly greater than that in Groups 2 [(0.05 ± 0.03) mm] and 3 [(0.05 ± 0.03) mm] (P < 0.05). At the 8 mm and 9 mm points, the transportation values in Group 4 [(0.12 ± 0.06) mm and (0.13 ± 0.05) mm] were significantly higher than those in Groups 2 [(0.05 ± 0.05) mm and (0.05 ± 0.05) mm] and 3 [(0.05 ± 0.04) mm and (0.06 ± 0.05) mm] (P < 0.05). At the 10 mm point, the transportation was significantly greater in Group 4 [(0.13 ± 0.06) mm] than in Group 2 [(0.06 ± 0.06) mm].@*Conclusion@#F6 SkyTaper exhibits better centering ability than Reciproc.

Clinical analysis of the shaping ability of Hyflex CM rotary NiTi files in curved root canals / 实用口腔医学杂志

60 curved root canals of permanent teeth with angles of curvature ranging from 15°to 40°(Schneider's methodology)were prepared using the instruments of Hyflex CM(HC) and ProTaper(PT) Universal respectively(n=30).Using standardized pre-and post-instrumentation paralleling periapical radiographs,canal curvature was determined by image analysis software and the clinical shaping effect of Hyflex CM and ProTaper rotary NiTi files were compared.The canal curvature in group HC and PT decreased by 4.54°±3.25° and 5.63°±3.84° respectively(between pre-and post-treatment in both groups,P0.05).Hyflex CM can meet the clinical necessity for the instrumentation of curved root canals.

Micro-CT Evaluation of Non-instrumented Canal Areas with Different Enlargements Performed by NiTi Systems

The aim of this study was to compare the percentage of non-instrumented area of root canals prepared with different enlargements using single-file reciprocating systems (Reciproc and WaveOne) and a conventional multi-file rotary (BioRaCe) system by micro-computed tomographic analysis. Thirty mesial roots of mandibular molars with moderate curvature (10° to 20°) presenting a type II Vertucci canal configuration and similar internal volume were chosen and scanned at an isotropic resolution of 14.16 µm. The sample was assigned to 3 groups (n=10) according to the system used for root canal preparation: Reciproc, WaveOne, and BioRaCe groups. Second and third scans were taken after the canals were prepared with instruments sizes 25 and 40, respectively. The recorded images of the surface area voxels of the canals, before and after preparation were examined from the furcation level to the apex to quantify the non-instrumented surface. Statistical data were compared using GLM for repeated-measures with a significance level set at 5%. Instrumentation systems did not influence the percentage of untouched root canal surfaces (p=0.690) whilst a significant reduction in the percentage of static voxels was observed after the enlargement of the root canal (p=0.010) in all groups (p=0.507). None of the systems was able to prepare the entire surface area of the mesial root canal of mandibular molars. The increased final apical size resulted in a significant positive effect on the shaping ability of the tested systems.

Resumo O objetivo deste estudo foi comparar a porcentagem de área não-instrumentada de canais radiculares preparados com diferentes ampliações utilizando sistemas reciprocantes de lima única (Reciproc e WaveOne) e um sistema rotatório convencional de múltiplas limas (BioRaCe) usando a análise da micro tomografia computadorizada. Trinta raízes mesiais de molares inferiores com curvatura moderada (10º a 20º) apresentando a configuração classe II de Vertucci e semelhança de volume do canal foram selecionadas e escaneadas em uma resolução isotrópica de 14,16 µm. A amostra foi dividida em 3 grupos (n=10) de acordo com o sistema utilizado para a preparação do canal radicular: grupo Reciproc, grupo WaveOne e grupo BioRaCe. Segundo e terceiro escaneamentos foram realizados após os canais serem preparados com instrumentos tamanhos 25 e 40, respectivamente. As imagens registradas de voxels da área de superfície dos canais, antes e após o preparo, foram examinadas desde o nível da furca até o ápice para quantificar a superfície não instrumentada. Os dados foram comparados estatisticamente através de GLM para medidas repetidas com um nível de significância de 5%. Os sistemas de instrumentação não influenciaram o percentual de superfícies não tocadas dos canais radiculares (p=0,690), enquanto que uma redução significativa no percentual de voxels estáticos foi observada após o alargamento do canal radicular (p=0,010) em todos os grupos (p=0,507). Nenhum dos sistemas foi capaz de preparar toda a área de superfície do canal mesial dos molares inferiores. O aumento do tamanho final apical resultou num efeito positivo significativo sobre a capacidade de modelar dos sistemas testados.

A comparison of the shaping ability of reciprocating NiTi instruments in simulated curved canals

OBJECTIVES: The study was to compare the shaping ability of Reciproc (VDW) and WaveOne (Dentsply Maillefer) instruments compared with ProTaper, Profile and hand instrument during the preparation of simulated root canals. MATERIALS AND METHODS: Five groups (n = 5) were established. Reciproc, WaveOne, ProTaper, Profile and K file (K-flexo file) were used to prepare the resin simulated canals. A series of preoperative and postoperative images were taken by a microscope and superimposed in 2 different layers. The amount of resin removed from both the inner and the outer sides of the canal was measured to the level of 10 mm from the apical tip, with a 1 mm increment. RESULTS: The mean of resin removal from the inner canal wall was not different from the outer canal wall for Reciproc and WaveOne groups at apical third (1 - 3 mm level). There was no difference in the change of working length and maintenance of canal curvature. NiTi instruments are superior to stainless-steel K file in their shaping ability. CONCLUSIONS: Within the limitation of this present study, Reciproc and WaveOne instruments maintained the original canal curvature in curved canals better than ProTaper and Profile, which tend to transport towards the outer canal wall of the curve in the apical part of the canal.

A comparison of the shaping ability of four rotary nickel-titanium files in simulated root canals / 대한치과보존학회지

The purpose of this study was to compare the root canal shaping ability of 4 rotary NiTi instruments in simulated root canals. For the preparation of thirty two curved root canals, Mtwo instruments using "single length"technique, and Profile, ProTaper Universal, and K3 using crown-down technique (N = 8) were used. All canal samples were prepared by reaching an apical canal size of #30. Pre- and post-instrumentation digital images were recorded and an assessment of canal shape was determined using a computer image analysis program SigmaScan Pro (Systat Software Inc., San Jose, CA, USA). The changes of the dimension of inner walls of canals, (2) the changes of the dimension of outer walls of canals, and (3) the centering ratio were measured at 7 measuring points, and then data were statistically analyzed using one-way ANOVA and Duncan's test. The results were as below; 1. The root canal shaping ability of Profile was significantly faster than that of other rotary NiTi instruments (p < 0.05). 2. The deformation and fracture of all instruments used for this study were not experienced. 3. In the degree of changes of the dimension of inner walls of canals, Profile demonstrated the lowest changes of the dimension of inner walls of canals except at the measuring points of the 1 and 2 mm (p < 0.05). However, the ProTaper Universal showed the highest changes of the dimension of inner walls of canals at all measuring points (p < 0.05). 4. In the degree of changes of the dimension of outer walls of canals, Mtwo demonstrated the lowest changse of the dimension of outer walls of canals except at the measuring point of the 1 mm (p < 0.05). However, Profile exhibited the highest changes of the dimension of outer walls of canals at the measuring points of 3 and 4 mm and ProTaper Universal and K3 showed the largest changes of the dimension of outer walls of canals at the measuring points of 1, 2, 6, and 7 mm (p < 0.05). 5. In degree of centering ratio, Profile demonstrated the least centering ratio comparing with the centering ratio shown by other NiTi instruments at the measuring points of 1, 4, 5, and 6 mm. Results suggest that in the coronal part of canal preparation, active cutting files such as ProTaper Universal may efficiently flare the canal orifice and form a better taper, and in the apical part of the canal, files which have a better centering ability such as Profile may maintain the original canal curvature and reduce the shaping time.

Comparison of shaping ability between single length technique and crown-down technique using Mtwo rotary file / 대한치과보존학회지

The aims of this study were to compare the shaping effect and safety between single length technique recommended by manufacturer and crown-down technique using Mtwo rotary file and to present a modified method in use of Mtwo file. Sixty simulated root canal resin blocks were used. The canals were divided into three groups according to instrument and the manner of using methods. Each group had 20 specimens. Group MT was instrumented with single length technique of Mtwo, group MC was instrumented with crowndown technique of Mtwo and group PT was instrumented with crown-down technique of ProTaper. All of the rotary files used in this study were operated by an electric motor. The scanned canal images of before and after preparation were superimposed. These superimposed images were evaluated at apical 1 to 8 mm levels. Angle changes were calculated. The preparation time, weight loss, instrument failure and binding, canal aberrations, and centering ratio were measured. Statistical analysis of the three experimental groups was performed with ANOVA and Duncan's multiple range tests for post-hoc comparison and Fisher's exact test was done for the frequency comparison. In total preparation time, group MT and group MC were less than group PT. In the aberrations, group MT had more elbows than those of group MC and group PT. The binding of group MC was least and group MT was less than group PT (P < 0.05). Under the condition of this study, crown-down technique using Mtwo rotary file is better and safer method than single length technique recommended by the manufacturer.

Comparison of shaping ability using various Nickel-Titanium rotary files and hybrid technique / 대한치과보존학회지

Currently, various Nickel-Titanium rotary files are used in endodontic treatment, but there is no one perfect system that can be applied to any clinical situation. Therefore, the combined uses of various file systems which can emphasize the advantages of each system are introduced as hybrid instrumentation. The ProTaper system is efficient in body shaping and apical pre-enlargement but is reported to have more possibility of transportation and produce more aberrations and deformation in more or less severe curved canals. Recently, new ProTaper system (ProTaper Universal) with different configuration and cross-sectional design to overcome the week points of ProTaper have been marketed. The purpose of this study was to compare and evaluate the shaping abilities of ProTaper, ProTaper Universal system, and two hybrid methods using S-series of ProTaper Universal and Hero Shaper or ProFile. The time lapses for instrumentation were measured and the used files were inspected for distortion. The pre- and post-instrumented root canals were scanned and superimposed to evaluate the aberrations and reduction of root canal curvature and change of radius of canal curvature. The increased canal width and apical centering ratio were calculated at 1, 2, 3, 4 and 5 mm levels from apical foramen. Under the conditions of this study, the ProTaper Universal seems to have better shaping ability than ProTaper in terms of instrumented width and instrumentation time. It may be suggested that the ProTaper Universal system is efficient as much as hybrid instrumentation using ProTaper and other constant-tapered NiTi file systems in highly experienced operators.

Comparison of shaping ability of rotary Ni-Ti file systems used by undergraduates / 대한치과보존학회지

The purpose of this study was to compare the shaping ability of three Ni-Ti file systems used by dental students or the experts and consequently to aid in choosing a proper systems for educational courses of dental students and beginners. Fifty students and ten dentists who have clinical experience over two years prepared 180 simulated root canals in resin blocks with three Ni-Ti systems; ProFile(R) (PF), HeroShaper(R) (HS), K3TM (K3). After preparation, the Ni-Ti files were evaluated for distortion and canal preparation time was recorded. The images of pre- and post-instrumented canals were scanned and superimposed. Amounts of increased canal widths, deviation, and centering ratio were calculated at apical 1, 3 and 5 mm levels and statistical analysis was performed. The results were as follows: 1. HS showed the shortest preparation time and instrumented canal width in K3 was significantly larger than other groups (P < 0.05). 2. At 1 and 3 mm levels, all groups had outward deviation. In student group, at the 1 mm level, PF had the least deviation (P < 0.05). 3. In the centering ratio, the PF had the best centering ability compared to the others at 5 mm level. At 1 and 3 mm levels, HS and PF had better abilities than K3. Student group had better ratio than the expert at 3 mm level with PF (P < 0.05). Based on the results, it is surmised that the ProFile(R) is the safest and most ideal instrument for students and beginners.

The effect of different flute design and torque-controlled motor on the shaping ability of simulated resin root canals / 대한치과보존학회지

The purpose of this study was to compare the shaping ability of the two different Ni-Ti file systems and the two different engine systems in simulated canals. A total of four groups of each 10 were tested. Each group was instrumented with HeroShaper(R)and Endo-Mate2(R) (Group HE), HeroShaper(R) and Tecnika(R) (Group HT), ProFile(R) and Endo-Mate2(R) (Group PE), and ProFile(R) and Tecnika(R) (Group PT). Canal preparation time was recorded. The images of pre- and post- instrumented root canals were scanned and superimposed. The amounts of increased width and centering ratio were measured and calculated at apical 1, 3 and 5 mm levels. These data were statistically analyzed with one-way ANOVA and Duncan's multiple range test The results of this study were as follows; 1. Canal preparation time of HT group was the shortest (p < 0.05). 2. The amount of increased canal width in HE group was significantly larger than PT group at apical 1 mm level (p < 0.05). At apical 3 mm level, PT group was significantly smaller than other groups (p < 0.05). At apical 5 mm level, PE group was significantly larger than PT group (p < 0.05). 3. The amount of centering ratio in HE group was significantly larger than other groups (p < 0.05). At apical 5 mm level, HT group was significantly larger than PE group and PT group (p < 0.05). Under the condition of this study, torque-controlled endodontic motor is safer than no torque controlled motor, especially when the active file is used.

Relative efficacy of three Ni-Ti file systems used by undergraduates / 대한치과보존학회지

The purpose of this study was to compare and evaluate the shaping ability of the three different Ni-Ti file systems used by undergraduate students. Fifty undergraduate students prepared 150 simulated curved root canals in resin blocks with three Ni-Ti file systems - ProFile(R) (PF), Manual ProTaper(R) (MPT), Rotary ProTape(R) (RPT). Every student prepared 3 simulated root canals with each system respectively. After root canal preparation, the Ni-Ti files were evaluated for distortion or breakage. Assessments were made according to the presence of various types of canal aberrations. The pre- and post-instrumented canal images were attained and superimposed. The instrumented root canal width were measured and calculated for the net transportation (deviation) and the centering ratio. Under the condition of this study, both ProTaper(R) systems allowed significantly more removal of root canal wall than the ProFile(R) system. In the important other aspects such as the centering ratio, there was no significant differences between the systems. Novice dental students were able to prepare curved root canals with any kinds of Ni-Ti file systems with little aberration and great conservation of tooth structure. Students want to learn effective methods and at the same time simple rotary procedures. The rotary ProTaper(R) systems were one of the most compatible to these students from the point of view of cutting ability. The ProFile(R) system was also compatible in safe and gentle shaping.

A comparison of shaping ability of the three ProTaper(R) instrumentation techniques in simulated canals / 대한치과보존학회지

The purpose of this study was to compare the shaping ability of the three ProTaper(R) instrumentation techniques in simulated canals. Thirty resin blocks were divided into 3 groups with 10 canals each. Each group was instrumented with manual ProTaper(R) (Group M), rotary ProTaper(R) (Group R), and hybrid technique (Group H). Canal preparation time was recorded. The images of pre- and post-instrumented root canals were scanned and superimposed. The amounts of canal deviation, total canal width, inner canal width, outer canal width and centering ratio were measured at apical 1, 2, 3, 4, 5 and 6 mm levels. 1. Canal preparation time was the shortest in R group (p 0.05). 3. The amounts of inner canal width in R group was larger than M group at the 1 mm level and H group was larger than R group at the 6 mm level (p < 0.05). The amounts of outer canal width in R group was larger than H group only at the 1 mm level (p < 0.05). 4. The direction of canal deviation in H, R group at the 1, 2, 3 mm levels was outward and that in M group at the 1, 2 mm levels was inward. The amounts of canal deviation in H group was larger than R group at the 6 mm level (p < 0.05). 5. The amounts of centering ratio in H group was larger than R group at the 6 mm level (p < 0.05).

Shaping ability of four rotary nickel-titanium instruments to prepare root canal at danger zone / 대한치과보존학회지

The aim of this study was to evaluate the shaping abilities of four different rotary nickel-titanium instruments with anticurvature motion to prepare root canal at danger zone by measuring the change of dentin thickness in order to have techniques of safe preparation of canals with nickel-titanium files. Mesiobuccal and mesiolingual canals of forty mesial roots of extracted human lower molars were instrumented using the crown-down technique with ProFile, GT(TM) Rotary file, Quantec file and ProTaper(TM). In each root, one canal was prepared with a straight up-and-down motion and the other canal was with an anticurvature motion. Canals were instrumented until apical foramens were up to size of 30 by one operator. The muffle system was used to evaluate the root canal preparation. After superimposing the pre- and post-instrumentation canal, change in root dentin thickness was measured at the inner and outer sides of the canal at 1, 3, and 5 mm levels from the furcation. Data were analyzed using two-way ANOVA. Root dentin thickness at danger zone was significantly thinner than that at safe zone at all levels (p 0.05). ProTaper removed significantly more dentin than other files especially at furcal 3 mm level of danger and safe zones (p < 0.05) Therefore, it was concluded that anticurvature motion with nickel-titanium rotary instruments does not seem to be effective in danger zone of lower molars.