Elimination of E. faecalis and C. albicans Biofilm: A comparison between single and multiple file systems in an Ex Vivo study

To evaluate whether the WaveOne Gold and Reciproc single file instrumentation systems, are effective in reducing the microbial load of a mixed biofilm and the cleaning of apical third compared to the Twisted File Adaptive system (multiple- file system). Seventy mesial roots of the first and second molars were included and randomly divided into three experimental groups (n=20, n=10 controls). Biofilms were formed inside canals over 31 days. After instrumentation with the unique file systems, WaveOne Gold and Reciproc and the multiple file system Twisted File Adaptive, using 2.25% sodium hypochlorite as an irrigant in all cases, a count of colony forming units was performed using serial dilutions, cleaning of the apical third was evaluated using scanning electron microscopy. Comparisons amongst groups were made by using parametric and non-parametric statistics, according to a normal or non-normal data distribution, respectively. No significant differences in the reduction of the microbial load after employing a single-file system in comparison to the multiple-file system were found; in addition, the cleaning of the apical third was similar for the three different instrumentation systems. The single-file system is equal in effectiveness compared with the multiple-file system in reducing the microbial load.

Evaluar si los sistemas de instrumentación de lima única, como WaveOne Gold y Reciproc son efectivos para reducir la carga microbiana de un biofilm mixto y la limpieza del tercio apical, comparado con los sistemas de limas múltiples, como Twisted File Adaptive. Setenta raíces mesiales de primeros y segundos molares fueron incluidos y divididos de forma aleatoria en tres grupos experimentales (n=20, n=10 controles). El biofilm fue formado en el interior de los conductos durante 31 días. Después se instrumentó con los sistemas de lima única (WaveOne Gold y Reciproc) y el sistema de limas múltiples Twisted File Adaptive, usando hipoclorito de sodio al 2.5% en todos los casos. El conteo de unidades formadoras de colonias se realizó usando diluciones seriales, la limpieza del tercio apical se evaluó empleando el microscopio electrónico de barrido. La comparación entre grupos se realizó con pruebas paramétricas y no paramétricas, de acuerdo con la distribución normal y no normal de los datos, respectivamente. No hubo una diferencia significativa en la reducción de la carga microbiana después de emplear los sistemas de lima única en comparación a los de limas múltiples, además, la limpieza del tercio apical fue similar en los 3 diferentes sistemas de instrumentación. Los sistemas de lima única son igual de efectivos para reducir la carga microbiana comparados con los sistemas de limas múltiples.

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 temperature effect on cyclic fatigue resistance of nickel-titanium instruments in a double-curved canal: a comparative study / Avaliação do efeito da temperatura na resistência a fadiga cíclica de instrumento níquel titânio em canal com dupla curvatura: estudo comparativo

Objective: To investigate the effect of room and body temperatures on cyclic fatigue resistance of three endodontic nickel-titanium rotary files: Hyflex EDM (HEDM) (Coltene/Whaledent, Switzerland), WaveOne Gold (WOG) (Dentsply Maillefer, Switzer), and EdgeOne Fire (EOF) (EdgeEndo, Albuquerque, New Mexico, USA) in a double- curved canal. Material and Methods: In this study, Sixty NiTi rotary files were used. These files were divided into three groups (n = 20 for each group). Group A: HEDM (size 25, taper 0.08), group B: WOG (size 25, taper 0.07), and group C: EOF (size 25, taper 0.07). Each group was subdivided into two subgroups (n=10 for each subgroup). One of the subgroup was subjected to cyclic fatigue test at room temperature (20±1°C), while the other subgroup was subjected to cyclic fatigue test at body temperature (37±1°C). These files were tested by using a custom-made artificial canal with a double curvature (coronal curve: 60° curvature with 5 mm radius; apical curve: 70° curvature with 2 mm radius). All instruments were rotated according to the manufacturer instructions until the fracture occurred by using electric endodontic motor (Wave One, Dentsply Maillefer, Ballaigues, Switzerland). The number of cycles to fracture (NCF) and the fractured fragment length (FL) were recorded for each endodontic file. The data were gathered and statistically analyzed using shapiro-wilk test and two-way ANOVA test. The statistical significance was set at 0.05. Results: The NCF of WOG and EOF were significantly lower at body temperature as compared to room temperature (p ≤ 0.05), whereas no difference was observed in NCF of HEDM at body and room temperatures (p>0.05). At 20±1°C, the results showed a non-significant difference between NCF of WOG and EOF (p>0.05), while the NCF of HEDM was significantly lower than the other groups (p ≤ 0.05). At 37±1°C, the results showed a non-significant difference in NCF among the tested endodontic files (p ≤ 0.05). There is non-significant difference in FL of each group at (20±1°C) and (37±1°C) (p>0.05). No statistical difference in FL among the tested files at room and body temperatures (p>0.05). Conclusion: The temperature has a significant effect on cyclic fatigue resistance of EOF and WOG, whereas no effect was observed on cyclic fatigue resistance of HEDM. WOG and EOF had a comparable NCF, while HEDM had a lower NCF than other groups at room temperature. At body temperature, all tested files have a comparable NCF. These results were attributed to the type of the alloy and heat treated that was used to manufacture these endodontic files. The cyclic fatigue test should be done at body temperature (AU)

Objetivo : Investigar o efeito das temperaturas ambiente e corpórea na resistência a fadiga cíclica em três instrumentos endodônticos rotatório de níquel-titânio: Hyflex EDM (HEDM)(coltene/Whaledent, Switzerland), WaveOne Gold (WOG) Dentsply Maillefer, Switzer), e EdgeOne Fire (EOF) (EdgeEndo, Albuquerque, New Mexico, USA) em canais com dupla curvatura. Material e Métodos : Neste estudo foram utilizadas sessenta limas endodônticas rotatórias. Esses grupos foram divididos em três grupos (n=20). Grupo A: HEDM (tamanho 25, conicidade 0.08), grupo B: WOG (tamanho 25, conicidade 0.07), e grupo C: EOF (tamanho 25, conicidade 0.07). Cada grupo foi subdivididos em dois subgrupos (n=10). Um dos subgrupos foi submetido ao teste de fadiga cíclica em temperatura ambiente (20±1°C), enquanto o outro subgrupo foi submetido a ao teste de fadiga cíclica em temperatura corpórea (37±1°C). Essas limas foram testadas em um canal artificial feito sob medida com duas curvaturas (curva coronal: curvatura de 60º e com 5 mm de raio; curva apical: curvatura de 70º com 2mm de raio); Todos os instrumentos foram rotacionados de acordo com a instrução do fabricante até que a fratura ocorresse utilizando um motor endodôntico elétrico (Wave One, Dentsply Maillefer, Ballaigues, Switzerland). O número de ciclos até a fratura (NCF) e a comprimento do fragmento fraturado (FL) foram registrados para cada lima endodôntica. Os dados foram coletados e analisados pelo teste shopiro-wilk e ANOVA two-way. A significância estatística foi 0.05. Resultados: O NCF do WOG e do WOF foi significantemente menor na temperatura corpórea em comparação à temperatura ambiente (p ≤ 0.05), enquanto não foi observada diferença entre NCF em HEDM em temperatura corpórea e temperatura ambiente (p>0.05). Em 20±1°C, os resultados mostraram diferença não significativa entre o NFC com WOG e EOF (p>0.05), enquanto o NCF com HEDM foi significante menor que os demais grupos (p ≤ 0.05). A 37±1°C, os resultados mostraram diferença não significativa em NCF entre as limas endodônticas testadas (p ≤ 0.05). Há diferença não significativa no FL de cada grupo (20±1°C) e (37±1°C) (p>0.05). Não houve diferença estatisticamente diferente no FL entre as limas testadas nas temperaturas ambiente e corporal (p>0,05). Conclusão: A temperatura tem efeito significativo na resistência a fadiga cíclica do EOF e WOG, enquanto não foi observado nenhum efeito na resistência a fadiga cíclica do HEDM. WOG e EOF tiveram um NCF comparável, enquanto HEDM teve um NCF menor do que os outros grupos em temperatura ambiente. À temperatura corporal, todas as limas testas apresentam semelhante NCF. Esses resultados foram atribuídos ao tipo de liga e ao tratamento térmico que foi utilizado na fabricação. O teste de fadiga cíclica deve ser feito à temperatura corporal (AU)

Surface profile of different heat-treated nickel-titanium files before and after root canal preparation

Abstract The aim of this study was to evaluate surface wear, presence of microcracks and surface irregularities of WaveOne (WO) and WaveOne Gold (WOG) instruments before and after multiple uses. Eight Primary instruments of the WO and WOG systems were evaluated, each one was used to prepare six mesial canals of extracted human mandibular molars. The surface of the instruments was evaluated before use (T0), after instrumentation of three (T1) and six (T2) root canals. Surface wear was analyzed using a three-dimensional optical profiler and the presence of microcracks and surface irregularities were evaluated using a tabletop scanning electron microscopy. The Friedman test was used to assess surface wear and Kruskal-Wallis test to evaluate the presence of microcracks and surface irregularities, with a 5% significance level. There was a significant increase in wear in both groups at T2, compared to T0 (p=0.0003). The surface wear after instrumentation of six canals (T2-T0) was statistically greater in the WOG group, than in the WO group (p=0.02), where the presence of microcracks was significantly greater and increased after multiple uses (p<0.05). The presence of surface irregularities in the cutting blade before and after use was statistically greater in the WOG group than WO group (p<0.05). Wear of the cutting blade, microcracks and surface irregularities were observed on the surface topography of all the instruments after multiple uses. These surface changes may affect the cutting efficiency of WOG files and increase the risk of fracture of WO files.

Resumo O objetivo deste estudo foi avaliar o desgaste de superfície, a presença de microtrincas e irregularidades superficiais dos instrumentos WaveOne (WO) e WaveOne Gold (WOG) antes e após múltiplos usos. Oito instrumentos Primary dos sistemas WO e WOG foram avaliados, cada um utilizado no preparo de seis canais mesiais de molares inferiores humanos extraídos. A superfície dos instrumentos foi avaliada antes do uso (T0), após a instrumentação de três (T1) e seis (T2) canais radiculares. O desgaste de superfície foi analisado utilizando um perfilômetro ótico tridimensional e a presença de microtrincas e irregularidades superficiais foram avaliadas usando um microscópio eletrônico de varredura de bancada. O teste de Friedman foi usado para avaliar o desgaste de superfície e o teste de Kruskal-Wallis para avaliar a presença de microtrincas e irregularidades superficiais, com nível de significância de 5%. Houve um aumento significativo no desgaste em ambos os grupos em T2, comparado a T0 (p=0.0003). O desgaste de superfície após a instrumentação de seis canais (T2-T0) foi estatisticamente maior no grupo WOG que no grupo WO (p=0.02), onde a presença de microtrincas foi estatisticamente maior e aumentou após os múltiplos usos (p<0.05). A presença de irregularidades na superfície da lamina de corte antes e após o uso aumento significativamente no grupo WOG comparado ao grupo WO (p<0.05). Desgaste da lâmina de corte, microtrincas e irregularidades superficiais foram observadas na topografia de superfície de todos os instrumentos após os múltiplos usos. Essas alterações na superfície podem afetar a eficiência de corte dos instrumentos WOG e amentar o risco de fratura dos instrumentos WO.

Avaliação das propriedades físico-químicas de instrumentos reciprocantes de níquel-titânio tratados termicamente / Evaluation of the physicochemical properties of heat-treated nickel-titanium reciprocating instruments

Os instrumentos endodônticos de níquel-titânio acionados a motor foram desenvolvidos para se obter um preparo químico-mecânico mais rápido e seguro, no entanto, esses instrumentos apresentam como desvantagem o risco de fraturar durante o seu uso. Diante disso, os fabricantes têm desenvolvido mudanças no design dos instrumentos, nos acabamentos das ligas e na cinemática de uso, pois são características que contribuem para que as fraturas aconteçam. O objetivo deste estudo foi avaliar e comparar propriedades mecânicas de novos instrumentos de níquel-titânio com memória controlada lançados no mercado. Os sistemas WaveOne Gold (WOG; Dentsply Sirona, Ballaigues, Switzerland), WA1 File (WA1; TDKaFile, Cidade do México, México) e X1 File (X1; MK Life, Porto Alegre, RS, Brasil) foram submetidos ao teste de resistência à torção, de acordo com a norma ISO 3630-1, ao teste rigidez à flexão, através do ensaio de flexão em cantiléver (45º) e ao teste de resistência à flambagem. Os resultados foram avaliados através da análise de variância (ANOVA), o teste F e o teste de Tukey, considerando um nível de significância de 5%. No teste de resistência à torção os instrumentos WOG apresentaram maior deflexão angular, ou seja, maior resistência à fratura em torção, enquanto os instrumentos WA1 a menor e na comparação do torque máximo em torção não houve diferença estatística significante entre os sistemas. Nos testes de rigidez a flexão e resistência à flambagem houve diferença estatística significante entre os 3 sistemas, sendo os instrumentos X1 os mais rígidos. No primeiro teste os instrumentos WA1 se apresentaram como os mais flexíveis e no segundo, os instrumentos WOG. Conclui-se que os instrumentos WOG, WA1 e X1 mostraram diferenças estatísticas nos testes mecânicos, sendo os instrumentos WOG e WA1 os mais resistentes à fratura por torção e os mais flexíveis, diferentemente dos instrumentos X1 que se apresentaram mais susceptíveis à fratura por torção e menos flexíveis (AU)

Reciprocating nickel-titanium endodontic instruments have been developed to obtain a faster and safer preparation, however, these instruments have the disadvantage of fracturing during use. Facing this disadvantage, manufacturers have developed changes in instrument design and alloy finishes, as metallurgical characteristics are one of the factors that contribute to fractures. The aim of this study was to evaluate and compare mechanical properties of new nickel-titanium instruments with controlled memory. The WaveOne Gold (WOG; Dentsply Sirona, Ballaigues, Switzerland), WA1 File (WA1; TDKaFile, Mexico City, Mexico) and X1 File (X1; MK Life, Porto Alegre, RS, Brazil) systems were subjected to the torsional fatigue test, according to the ISO 3630-1 standard, flexural stiffness test, through the cantilever flexion test (45°) and buckling resistance test. The results were evaluated through analysis of variance (ANOVA), the F test and the Tukey test, considering a significance level of 5%. In the torsional fatigue test, the WOG instruments showed greater angular deflection, that is, greater resistance to torsional fracture and the WA1 instruments the lesser, and when comparing the maximum torsional torque, there was no statistically significant difference between the systems. In the flexural stiffness and buckling resistance tests, there was a statistically significant difference between the 3 systems, with the X1 instruments being the most rigid. In the first test, the WA1 instruments were the most flexible followed by the WOG instruments. In conclusion, the WOG, WA1 and X1 instruments showed differences in the mechanical tests, with the WOG and WA1 instruments being the most resistant to torsion fracture and the most flexible, unlike the X1 instruments that were more susceptible to torsion fracture and also the most rigid (AU).

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.

The Effect of AH Plus and GuttaFlow Bioseal Sealers on the Fracture Resistance of Endodontically Treated Roots Instrumented with Reciprocal Rotary Systems

Objective: The objective of this study was to assess and compare the fracture resistance of roots treated endodontically using WaveOne gold, Reciproc blue, AH plus sealer and GuttaFlow Bioseal sealer. Materials and methods: Total 48 human mandibular premolars with single root were decoronated to a length of 13 mm. The roots were arbitrarily divided into 3 main groups (n=16 each group). Group I control group (roots were instrumented but not obturated), Group II obturated with gutta-percha and GuttaFlow Bioseal sealer and Group III obturated with gutta-percha and AH plus sealer. Each main group was additionally divided into 2 subgroups (n=8 each subgroup) conforming to the system used in root canal preparations, Subgroup A: Reciproc blue system and Subgroup B: WaveOne gold system. All root samples were kept for 1 week at 100% humidity to permit the sealers to set completely. Each sample was then exposed to fracture test utilizing a universal test machine, the data were analyzed statistically with one-way ANOVA test, two-way ANOVA test and Dunnett test (2-sided) at a significant level of 0.05. Results: The results revealed that the highest mean value of fracture resistance was noted in Group IIIB (611.125) followed by Group IIIA (543.250), Group IIB (519.875), Group IIA (511.875), Group IB (270.125) and Group IA (267.875) respectively with statistically highly significant differences among the different groups when compared to the control group. Conclusion: From the results of this study, it seems that the use of AH plus and GuttaFlow Bioseal sealers improved the fracture strength of instrumented roots whereas preparation of the root canals with WaveOne gold and Reciproc blue systems without obturation weakened the tooth structures.

Evaluation of Apically Extruded Debris and Irrigants during Root Canal Preparation using Different Rotary Instrumentation Systems: An In-vitro Comparative Study

Background: Different instrumentation systems and techniques are used in the instrumentation of the root canal system which can result in debris formation that may be extruded beyond the apical foramen and cause post-operative pain. Aim of the study: Aim of the current study was to compare the amount of apically extruded debris and irrigants during instrumentation using 2 reciprocating single file systems (WaveOne Gold, Reciproc blue) and 2 continuous rotation file systems (ProTaper Gold, 2Shape) and comparing them to the control group (ProTaper Universal). Materials and Methods: Total 50 palatal roots of freshly extracted human maxillary first molars were collected for this study. Teeth were decoronated to a unified length of 15 mm, and then pushed through a pre-perforated rubber cap of pre-weighed glass vial then the root-cap complex was fitted on a glass vial and rubber dam ligated with dental floss was used to cover the glass vial for preventing the coronally extruded debris and irrigants from contaminating the external surface, gauge 25 needle was inserted parallel to the root surface through the rubber dam and cup. Samples were then randomly divided into 5 groups. Results: Data obtained were statistically analyzed using One Way ANOVA and LSD tests. The result showed that all groups resulted in apical extrusion of debris and irrigants, as it showed that the 2Shape Group B, Wave One Gold Group C and Reciproc blue Group D are statistically comparable, while ProTaper Gold Group A and ProTaper Universal Groups E showed statistically significant difference (p<0.05). Conclusions: All of the systems resulted in apical extrusion. There was no influence of kinematic movements on apical extrusion. The 2shape file system produced the least amount of apical extrusion while the ProTaper Universal showed the greatest amount.

Cyclic fatigue resistance of the WaveOne Gold Glider, ProGlider, and the One G glide path instruments in double-curvature canals

OBJECTIVES: The aim of this study was to compare the cyclic fatigue resistance of the WaveOne Gold Glider, ProGlider and One G glide path instruments in artificial double-curvature canals. MATERIALS AND METHODS: This study included 15 WaveOne Gold Glider (size 15/0.08), 15 ProGlider (size 16/0.08), and 15 One G (size 16/0.06) nickel titanium files. The files were used in accordance with the manufacturer's instructions until they were broken in artificial double-curvature canals made of stainless steel. The time to fracture was recorded via a digital stopwatch and the number of rotations until fracture was also calculated. The data were statistically analyzed via the Kruskal-Wallis test. RESULTS: The highest average number of rotations until fracture of the files was found for the WaveOne Gold Glider, followed by ProGlider and One G in order. Statistically significant differences were present between all groups of files (p < 0.05). CONCLUSIONS: In our study, the resistance of the WaveOne Gold Glider nickel-titanium (Ni-Ti) file to cyclic fatigue in S-shaped curved canals was found to be higher than that of the ProGlider and One G Ni-Ti files.

Estudio comparativo de la conformación generada con las limas ProGlider y WaveOne Gold Glider en conductos curvos simulados / A comparative study of the shaping ability generated with ProGlider and WaveOne Gold Glider in simulated curved canals

Objetivo: Comparar, en conductos curvos simulados de Endo Training Blocks, la conformación alcanzada por las limas ProGlider y WaveOne Gold Glider. Materiales y métodos: Se utilizaron 20 Endo Training Blocks con conductos curvos. Los conductos fueron teñidos con tinta china. Los bloques fueron divididos al azar en dos grupos, A y B, de 10 bloques cada uno. En el grupo A los conductos se permeabilizaron y conformaron con limas ProGlider, y en el grupo B, con limas WaveOne Gold Glider, accionadas con movimiento rotatorio y reciprocante, respectivamente. Para realizar la evaluación, los conductos se dividieron en tres tercios (cervical, medio y apical), para lo cual se colocó debajo de cada bloque una hoja milimetrada, y en esa posición fueron fotografiados. Se observaron las imágenes y se estableció la siguiente categorización: 0, no conformado; 1, conformación parcial; 2, conformado. La comparación entre los dos grupos dentro de cada tercio fue realizada por medio de la prueba de Chi cuadrado o de la prueba exacta de Fisher, según correspondiera. La comparación entre tercios dentro de cada grupo fue efectuada con la prueba de Friedman. En ambos casos se fijó el nivel de significancia en P<0,05. Resultados: En los tres tercios evaluados, el WaveOne Glod Glider mostró mejores resultados que el ProGlider, obervándose diferencias estadísticas significativas entre los grupos dentro de cada tercio. La comparación entre tercios dentro de cada grupo mostró, en el grupo A, ausencia de diferencias significativas entre los tercios cervical y medio, en tanto el tercio apical fue significativamente diferente a los otros dos; en el grupo B hubo diferencias estadísticas significativas entre el tercio cervical y el medio, mientras no las hubo entre el apical y los otros dos. Conclusiones: En los tres tercios evaluados, el WaveOne Gold Glider mostró mejores resultados que el ProGlider (AU)

Aim: To compare in simulated curved canals of Endo Training Blocks, the shaping ability of ProGlider and WaveOne Gold Glider files. Materials and methods: Twenty Endo Training Blocks with curved canals were used. The simulated canals were dyed with China ink. The blocks were randomly assigned to two groups, A and B, of 10 blocks each. Group A canals were shaped with ProGlider files and group B ones with WaveOne Gold Glider files, operated with rotary and reciprocating motion respectively. For the evaluation, the canals were divided into three thirds (cervical, middle and apical). A sheet of graft paper was placed under each block and they were photographed. The images were observed and the following score was established: 0, not shaped; 1, partially shaped; 2, shaped. The comparison between the two groups within each third was made by means of the chi-square test or Fisher's exact test as appropriate. The comparison between thirds within each group was made by means of Friedman's test. In both cases, the level of significance was set at P<0.05. Results: WaveOne Gold Glider showed better results than ProGlider in the three evaluated thirds. Statistical significant differences were detected between groups in each third. The comparison between thirds within each group showed, in group A, no significant differences between the cervical and middle thirds, while the apical third presented significant differences with the other two. In group B, significant differences were observed between the cervical and middle thirds, while there were none between the apical and the other two thirds. Conclusions: In the three thirds evaluated, WaveOne Gold Glider showed better results than ProGlider (AU)

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)

The effect of root canal preparation on the surface roughness of WaveOne and WaveOne Gold files: atomic force microscopy study

OBJECTIVES: To examine the surface topography of intact WaveOne (WO; Dentsply Sirona Endodontics) and WaveOne Gold (WOG; Dentsply Sirona Endodontics) nickel-titanium rotary files and to evaluate the presence of alterations to the surface topography after root canal preparations of severely curved root canals in molar teeth. MATERIALS AND METHODS: Forty-eight severely curved canals of extracted molar teeth were divided into 2 groups (n = 24/each group). In group 1, the canals were prepared using WO and in group 2, the canals were prepared using WOG files. After the preparation of 3 root canals, instruments were subjected to atomic force microscopy analysis. Average roughness and root mean square values were chosen to investigate the surface features of endodontic files. The data was analyzed using one-way analysis of variance and post hoc Tamhane's tests at 5% significant level. RESULTS: The surface roughness values of WO and WOG files significantly changed after use in root canals (p < 0.05). The used WOG files exhibited higher surface roughness change when compared with the used WO files (p < 0.05). CONCLUSIONS: Using WO and WOG Primary files in 3 root canals affected the surface topography of the files. After being used in root canals, the WOG files showed a higher level of surface porosity value than the WO files.

Comparison of the shaping ability of novel thermally treated reciprocating instruments

OBJECTIVES: The present study aimed to evaluate the shaping ability of 2 thermally treated nickel-titanium reciprocating systems in simulated curved canals. MATERIALS AND METHODS: Forty simulated canals were prepared to apical size 25 using Reciproc Blue R25 (VDW) and WaveOne Gold Primary (Dentsply Sirona) instruments. Standard pre- and post-preparation images were taken and superimposed. The removal of resin material was measured at 5 standard points: the canal orifice, halfway between the canal orifice and the beginning of the curve, the beginning of the curve, the apex of the curve, and the end-point of the simulated canal. The data were analysed using the independent sample t-test with a 5% significance threshold. RESULTS: The canals in which Reciproc Blue R25 was used showed a significantly greater widening than those in which WaveOne Gold was used at 4 of the 5 measurement points (p < 0.05). The Reciproc Blue R25 instrument removed significantly more resin from the inner aspect of the curve at 2 of the 5 points and similar amounts at the remaining 3 points. At the 2 apical points, there was no significant difference between the Reciproc Blue R25 and WaveOne Gold Primary instruments. CONCLUSION: Both instruments respected the original canal anatomy; however, WaveOne Gold resulted in a more conservative shape with less transportation.

Effect of Reciprocating Systems and Working Lengths on Apical Microcrack Development: a micro-CT Study

Abstract The objective of this study was to evaluate the effect of root canal preparation with single-file reciprocating systems at different working lengths on the development of apical microcracks using micro-computed tomographic (micro-CT) imaging. Forty extracted human mandibular incisors were randomly assigned to 4 groups (n=10) according to the systems and working length used to prepare the root canals: Group A - WaveOne Gold at apical foramen (AF), Group B - WaveOne Gold 1 mm short of the AF (AF-1 mm), Group C - Unicone (AF) and Group D - Unicone (AF-1 mm). Micro-CT scanning was performed before and after root canal preparation at an isotropic resolution of 14 µm. Then, three examiners assessed the cross-sectional images generated to detect microcracks in the apical portion of the roots. Apical microcracks were visualized in 3, 1, 1, and 3 specimens in groups A, B, C, and D, respectively. All these microcracks observed after root canal preparation already existed prior to instrumentation, and no new apical microcrack was detected. For all groups, the number of slices presenting microcracks after root canal preparation was the same as before canal preparation. Root canal preparation with WaveOne Gold and Unicone, regardless of the working length, was not associated with apical microcrack formation.

Resumo O objetivo deste estudo foi avaliar o efeito da instrumentação de canais radiculares utilizando sistemas reciprocantes de lima única em diferentes comprimentos de trabalho sobre o desenvolvimento de microfissuras apicais utilizando imagens de microtomografia computadorizada (micro-CT). Quarenta incisivos inferiores humanos extraídos foram distribuídos aleatoriamente em 4 grupos (n=10) de acordo com os sistemas e comprimentos de trabalho utilizados para preparar os canais radiculares: Grupo A - WaveOne Gold no forame apical (FA), Grupo B - WaveOne Gold 1 mm aquém do FA (FA-1 mm), Grupo C - Unicone (FA) e grupo D - Unicone (FA-1 mm). Escaneamentos de micro-CT foram realizados antes e após o preparo dos canais a uma resolução isotrópica de 14 μm. Em seguida, três examinadores avaliaram as imagens de secção transversal geradas para detectar microfissuras na porção apical das raízes. Microfissuras apicais foram visualizadas em 3, 1, 1 e 3 espécimes nos grupos A, B, C e D, respectivamente. Todas essas microfissuras observadas após o preparo dos canais radiculares já existiam antes da instrumentação e não foi detectada nenhuma nova microfissura apical. Para todos os grupos, o número de cortes apresentando microfissuras após o preparo dos canais radiculares foi o mesmo verificado antes do preparo dos canais. A instrumentação de canais radiculares utilizando WaveOne Gold e Unicone, independentemente do comprimento de trabalho, não foi associada à formação de microfissuras apicais.

WaveOne Gold, un nuevo instrumento reciprocante para la conformación de los conductos radiculares / WaveOne Gold, a new reciprocating instrument for root canal shaping

El objetivo del presente artículo es describir y analizar el nuevo sistema de limas reciprocantes WaveOne Gold, evolución del sistema WaveOne presentado en 2010. Las mejoras en su diseño y en su metalurgia les otorgan más flexibilidad y aumentan su resistencia a la fatiga cíclica, lo cual brinda al clínico la posibilidad de instrumentar con más seguridad y confianza el sistema de conductos radiculares.

The aim of the present article is to describe and analyzethe new reciprocating system WaveOne Gold.This instrument, preceded by the WaveOne in 2010, showsimprovements in its design and in its metallurgy, providingmore flexibility and increasing its resistance to cyclic fatigue.Alfie D, García G, Rodríguez P. WaveOne Gold, un nuevo instrumento reciprocante para la conformaciónde los conductos radiculares. Rev Asoc Odontol Argent 2016;105:78-82.This gives the clinician greater security and confidence duringthe shaping of the root canal system.

Cyclic fatigue life of Tango-Endo, WaveOne GOLD, and Reciproc NiTi instruments

OBJECTIVES: To compare the fatigue life of Tango-Endo, WaveOne GOLD, and Reciproc NiTi instruments under static model via artificial canals with different angles of curvature. MATERIALS AND METHODS: Reciproc R25, WaveOne GOLD Primary, and Tango-Endo instruments were included in this study (n = 20). All the instruments were rotated in artificial canals which were made of stainless steel with an inner diameter of 1.5 mm, 45°, 60°, and 90° angles of curvatures and a radius of curvature of 5 mm until fracture occurred, and the time to fracture was recorded in seconds using a digital chronometer. The data were analyzed using Kruskal-Wallis and post-hoc Dunn tests were used for the statistical analysis of data in SPSS 21.0 software. RESULTS: Tango-Endo files were found to have significantly higher values than WaveOne GOLD and Reciproc files in terms of fatigue life (p 0.05). It was determined that increasing the angle of curvature of the stainless canals caused significant decreases in fatigue life of all of three files (p < 0.05). CONCLUSIONS: Within the limitations of the present study, the cyclic fatigue life of Tango-Endo in canals having different angles of curvature was statistically higher than Reciproc and WaveOne GOLD.