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.

Evaluación de la capacidad de centrado y transporte apical de los sistemas Reciproc Blue y XP-endo Shaper / Evaluation of the centering and apical transport capacity of Reciproc Blue and XP-endo Shaper systems

Resumen Objetivo: Comparar la capacidad de centrado y el transporte apical de los sistemas Reciproc Blue y XP-endo Shaper en bloques de resina con fotografías pre y posoperatorias yuxtapuestas, mediante un programa de análisis de imágenes. Materiales y Métodos: Se dividieron al azar 20 tacos de resina en dos grupos (n=10) preparados con XP-endo Sha- per y Reciproc Blue respectivamente. Se tomaron fotografías digitales de los tacos, antes y después de la preparación con cada sistema en una misma posición. Luego las fotografías obtenidas fueron yuxtapuestas mediante el software Photo shop. Se midieron las desviaciones del centro del conducto con respecto a la pared interna y externa del mismo en diversos puntos de referencia preestablecidos. Estos datos fueron analizados estadísticamente con el test de ANOVA. Resultados: Ambos sistemas produjeron transporte y desviación respecto a la trayectoria original del conducto radicular, pero el análisis estadístico (ANOVA Factorial 2x8) no cuantificó diferencias significativas entre ambos sistemas (p=0,4044) Conclusiones: Bajo las condiciones de este trabajo, ambos sistemas producen transporte y desviación respecto a la trayectoria original del conducto radicular.

Abstract Aim: To compare the centering capacity and apical transport of the Reciproc Blue and X-Pendo Shaper system in resin blocks with juxtaposed pre and postoperative photographs, using the Photoshop software. Materials and methods: 20 resin plugs were randomly divided into two groups (n=10) that were prepared with XP-endo Shaper and Reciproc Blue respectively. Digital photographs of the blocks were taken, before and after preparation, with each system in the same position. Then the obtained photographs were juxtaposed using Photoshop software. The deviations of the center of the canal, with respect to its inter nal and external wall, were measured at various pre-established reference points. These data were statistically analysed with the ANOVA test. Results: Both systems produced transport and deviation from the original trajectory of the root canal, but the statistical analysis (2x8 Factorial ANOVA) did not quantify significant differences between both systems (p=0.4044) Conclusions: Under the conditions of this work, both systems produce transport and deviation with respect to the original trajectory of the root canal.

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.

Apically extruded debris using passive ultrasonic irrigation associated with different root canal irrigants

Abstract The present study evaluated the amount of apically extruded debris after chemo-mechanical preparation (CMP) associated with passive ultrasonic irrigation (PUI) using four different root canal irrigants, namely, 6% sodium hypochlorite (NaOCl), 2% chlorhexidine gel + saline solution (2% CHXg+SS), 2% chlorhexidine solution (2% CHXs) and SS alone. Sixty mandibular premolars with single straight root canals were selected and randomly assigned into 4 groups (n=15) according to the root canal irrigant used as follows: G1 (PUI + NaOCl), G2 (PUI + CHXg+SS), G3 (PUI+CHXs) and G4 (PUI+SS). Reciproc® R25 files (25/.08) were used during CMP and the debris extruded from each tooth were collected in pre-weighted Eppendorf tubes and dried. The average weight of debris was assessed by using an analytical microbalance. Data were statistically analysed by using ANOVA and post-hoc Tukey's test (a=0.05). Debris extrusion was observed in all groups, irrespective of the root canal irrigating, with 2% CHXg + SS being associated with lower debris extrusion compared to other irrigants (p<0.05). No significant differences were observed between 6% NaOCl, 2% CHXs and SS. In conclusion, passive ultrasonic irrigation did not completely prevent apically extrusion of debris. PUI performed with 2% chlorhexidine gel + saline solution significantly minimized debris extrusion compared to 6% sodium hypochlorite, chlorhexidine solution and saline solution.

Resumo O presente estudo avaliou a quantidade de debris extruídos apicalmente após o preparo químico-mecânico (PQM) associado à irrigação ultrassônica passiva (IUP) em associação com quatro diferentes irrigantes - hipoclorito de sódio 6% (NaOCl), clorexidina gel 2% + solução salina (CLXg 2% + SS), solução de clorexidina 2% (CLXs 2%) e SS. Sessenta pré-molares inferiores com canais radiculares únicos e retos foram selecionados e aleatoriamente distribuídos em 4 grupos (n=15) de acordo com o irrigante utilizado: G1 (IUP + NaOCl), G2 (IUP + CLXg + SS), G3 (IUP + CLXs) e G4 (IUP + SS). Limas Reciproc® R25 (25/.08) foram utilizadas durante o PQM e os debris extruídos de cada dente foram coletados em tubos Eppendorf pré-pesados e secos. O peso médio de debris foi avaliado através de microbalança analítica, e os dados foram analisados estatisticamente utilizando ANOVA e teste de Tukey post hoc (a=0.05). Extrusão de debris foi observada em todos os grupos, independente do irrigante. CHXg 2% + SS foram associados a menor extrusão de debris comparado aos demais irrigantes (p<0.05). Não foram observadas diferenças estatisticamente significativas entre NaOCl 6%, CLXs 2% e SS. Concluindo, irrigação ultrassônica passiva não preveniu completamente a extrusão apical de debris, entretanto, IUP realizada com CLXg 2% + SS minimiza significativamente a extrusão de debris comparado ao NaOCl 6%, CLXs 2% e SS.

Evaluation of Surface Characteristic Changes of Reciproc, waveOne and WaveOne Gold Single Reciprocating Files Using Scanning Electron Microscopy before and after use: An in-vitro Study

The purpose of this study was to evaluate surface characteristics of Reciproc (R25) WaveOne (WO) &WaveOne Gold (WOG) files using SEM before and after use. Methods: fifteen primary files from each system were scanned for surface defects before instrumentation at 10x-1000x. Each file was planned to be used to instrument six root canals and then examined under SEM after preparing three and six canals at same magnifications. Data were scored and statistically analysed using CHI –SQ and Anova tests (p≤ 0.05). Results: Surface defects were detected in all study groups with higher values in WO & WOG group before use. Surface defects significantly increased in both WO and WOG groups after use as compared to R25. WO & WOG group showed significantly greater defects including metal strips, pitting, craters, micro-cracks and blunt edges (p≤ 0.05). Conclusions: Wave One Gold file has a different metallurgy due to its gold finish that does not enhance its resistance to surface defects during clinical use. Wave One and Wave One Gold showed significant increase in surface defects after six canal use which limits their usage in more than one teeth in single patient.

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.

Comparison of the ability of Reciproc and Reciproc Blue instruments to reach the full working length with or without glide path preparation

OBJECTIVES: The purpose of the present study was to compare the mean preparation times and frequency with which Reciproc and Reciproc Blue instruments reached the full working length in mandibular molars, with or without glide path preparation. MATERIALS AND METHODS: Previously untreated mesiobuccal and mesiolingual canals with completely formed apices were randomly divided into 6 groups (n = 50) depending on the usage of Reciproc (RC; VDW), Reciproc Blue (RC Blue; VDW), C-Pilot (CP; VDW), and R-Pilot (RP; VDW) files: RC, RC Blue, RC + C-Pilot (RC-CP), RC-Blue + C-Pilot (RC Blue-CP), RC+R-Pilot (RC-RP), and RC Blue + R-Pilot (RC Blue-RP). A glide path was prepared using the hand-operated C-Pilot or the machine-operated R-Pilot instruments, respectively. The χ2 test, analysis of variance, and the Tukey post hoc test were used for statistical comparisons. RESULTS: No statistically significant differences were observed in the distribution of the frequency of reaching the full working length in the RC (94%), RC Blue (88%), RC-CP (94%), RC Blue-CP (90%), RC-RP (96%), and RC Blue-RP (92%) groups (p > 0.05). CONCLUSIONS: Preparation of a glide path did not have a significant effect on reaching the full working length using these systems.

Evaluating the cutting efficiency of NiTi instruments with reciprocating motions / Avaliação da eficiência de corte de instrumentos NiTi com movimento reciprocante

Aim:This study tested a setup for in vitro experimental analysis of axial forces and torque during the preparation of artificial canals using nickel-titanium reciprocating endodontic files.Methods: The cutting efficiency of Reciproc (RC) and WaveOne (WO) reciprocating size 25/.08 instruments (n = 10) was evaluated, taking into account their dimensional and geometrical features. Measurements of the diameter at each millimeter from the tip, pitch length, helical angle, and cross-sectional design and area were assessed. Cutting efficiency tests were carried out on a specific bench device by measuring the torque and axial force required during artificial canal shaping. Statistical analysis was performed using one-way ANOVA (α = 0.05). Results:The WO samples showed larger A3 mean values than did the RC instruments (p < 0.0001), despite having equal diameters at 3mm from the tip (D3) (p = 0.521). The mean values of pitch length were higher for RC than for WO instruments (p< 0.0001), with consequently smaller helical angles (p < 0.0001). For the cutting efficiency tests, the required torque was lower for the RC group when compared to the WO group, but it was significant only in the first stage of insertion in the artificial canals (p = 0.008). Regarding the apical force, the RC instruments reached higher values when compared to the WO instruments (p = 0.04) in the second stage of cutting action. Conclusion: Reciproc instruments demonstrated statistically higher cutting efficiency when compared to WaveOne instruments.

Objetivo: Este estudo testa uma configuração para análise experimental in vitro de forças axiais e torque durante o preparo de canais artificiais usando instrumentos endodônticos reciprocantes de níquel-titânio. Métodos: Foi avaliada a eficiência de corte dos instrumentos reciprocantes tamanho 25 / 0,08 (n = 10) Reciproc (RC) e WaveOne (WO), levando em consideração suas características dimensionais e geométricas. Medidas do diâmetro a cada milímetro a partir da ponta, comprimento de pitch, ângulo helicoidal e desenho da área transversal e área foram avaliados. Testes de eficiência de corte foram realizados em um dispositivo de bancada específico, medindo-se o torque e a força axial exigidos durante a modelagem de canais artificiais. A análise estatística foi feita com ANOVA one-way (α = 0,05). Resultados: As amostras de WO mostraram valores médios A3 maiores do que os instrumentos RC (p <0,0001), apesar de terem diâmetros iguais a 3 mm da ponta (D3) (p = 0,521). Os valores médios do comprimento do pitch foram maiores para o RC do que para os instrumentos do WO (p < 0,0001), com consequentemente menores ângulos helicoidais (p < 0,0001). Para os testes de eficiência de corte, o torque necessário foi menor para o grupo RC em comparação com o grupo WO, mas significativo apenas no primeiro estágio de inserção nos canais artificiais (p = 0,008). Em relação à força apical, os instrumentos RC alcançaram valores maiores em relação aos instrumentos WO (p = 0,04) no segundo estágio de corte. Conclusão: Os instrumentos Reciproc demonstraram uma eficiência de corte estatisticamente superior em comparação com os instrumentos WaveOne.

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.

Estudio comparativo in vitro sobre la extrusión apical de detritus producida por los sistemas Mtwo y Reciproc / In vitro comparative study about apically extruded debris produced by Mtwo and Reciproc systems

Objetivo: evaluar cuantitativamente la cantidad de residuos extruidos a través del foramen apical, comparando los sistemas Mtwo y Reciproc. Materiales y métodos: se usaron 20 premolares inferiores unirradiculares, con ápice maduro, curvaturas de 0 a 10 grados y oramen permeable a limas tipo K flexibles #10 y #15. Se realizó la cavidad de acceso de manera convencional con piedra redonda de diamante y fresa Endo Z. Se determinó visualmente la longitud de trabajo a 1 mm del foramen apical. Los dientes fueron divididos al azar en dos grupos de 10 especímenes cada uno. Grupo 1: instrumentación con sistema Mtwo (VDW GmbH) a la longitud de trabajo. Grupo 2: instrumentación con sistema Reciproc (VDW GmbH) con movimientos de picoteo por tercios. Se utilizó como irrigante 12,5 ml de agua destilada por elemento dentario. Para la recolección de restos, se usó la técnica de Myers y Montgomery. Los residuos y el irrigante extruidos fueron recolectados en un frasco vial prepesado. El peso de los restos fue calculado por la diferencia de las medidas pre- y posinstrumentación. Resultados: los datos fueron analizados estadísticamente con el test de normalidad de Kolmogorov-Smirnov. Posteriormente, los datos de dichas variables, dependientes pre- y po-, fueron analizados con la prueba T para muestras pareadas. No se registraron diferencias significativas entre ambos grupos (P>0,05). Conclusión: ambos sistemas rotatorios produjeron extrusión apical de residuos de manera similar.

Influence of 4 kinds of Ni-Ti instruments on the fracture resistance of root after canal preparation / 实用口腔医学杂志

Objective:To evaluate the fracture resistance of roots instrumented with Reciproc,WaveOne,ProTaper and BLX respectively.Methods:50 extracted maxillary and 50 extracted mandibular anterior teeth were selected and randomly divided into 5 groups respectively(n =10).The teeth in the 4 experimental groups were instrumented by 4 the instruments respectively and the teeth in the control group were not treated.A vertical load was applied to the roots and the fracture load for each sample was recorded.The data were analyzed with SPSS 19.0 software.Results:After preparition the fracture load of the experimental groups was lower than that of the control (P ＜ 0.05),between the Reciproc and WaveOne groups (P ＞ 0.05),between ProTaper and BLX groups for maxi teeth (P ＞0.05),for mandibular teeth(P ＜ 0.05).The fracture load of Reciproc and WaveOne was higher than that of ProTaper and BLX(P ＜0.05).After making same taper shape using same root canal instrument,the mandibular anterior teeth had lower fracture resistances than the maxillary anterior teeth (P ＜ 0.05).Conclusion:Single-file reciprocating systems groups may decrease less fracture resistance than full-sequence rotary systems.with or without instrumentation,maxillary anterior teeth have higher fracture resistance than mandibular anterior teeth.

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.

Comparison of cyclic fatigue life of nickel-titanium files: an examination using high-speed camera

OBJECTIVES: To determine the actual revolutions per minute (rpm) values and compare the cyclic fatigue life of Reciproc (RPC, VDW GmbH), WaveOne (WO, Dentsply Maillefer), and TF Adaptive (TFA, Axis/SybronEndo) nickel-titanium (NiTi) file systems using high-speed camera. MATERIALS AND METHODS: Twenty RPC R25 (25/0.08), 20 WO Primary (25/0.08), and 20 TFA ML 1 (25/0.08) files were employed in the present study. The cyclic fatigue tests were performed using a dynamic cyclic fatigue testing device, which has an artificial stainless steel canal with a 60° angle of curvature and a 5-mm radius of curvature. The files were divided into 3 groups (group 1, RPC R25 [RPC]; group 2, WO Primary [WO]; group 3, TF Adaptive ML 1 [TFA]). All the instruments were rotated until fracture during the cyclic fatigue test and slow-motion videos were captured using high-speed camera. The number of cycles to failure (NCF) was calculated. The data were analyzed statistically using one-way analysis of variance (ANOVA, p < 0.05). RESULTS: The slow-motion videos were indicated that rpm values of the RPC, WO, and TFA groups were 180, 210, and 425, respectively. RPC (3,464.45 ± 487.58) and WO (3,257.63 ± 556.39) groups had significantly longer cyclic fatigue life compared with TFA (1,634.46 ± 300.03) group (p < 0.05). There was no significant difference in the mean length of the fractured fragments. CONCLUSIONS: Within the limitation of the present study, RPC and WO NiTi files showed significantly longer cyclic fatigue life than TFA NiTi file.

The effect of various kinematics on postoperative pain after instrumentation: a prospective, randomized clinical study

ABSTRACT Objective: To evaluate various kinematic movements on postoperative pain using a Reciproc system. Material and Methods: Fifty-six molar teeth were divided into four groups according to kinematics as follows: continuous rotation, 360° CCW – 30° CW, 270° CCW – 30° CW, and 150° CCW – 30° CW. Preoperative and postoperative pain levels using visual analogue scale (VAS), percussion pain, and analgesic intake were recorded for each subject. Postoperative pain levels at 1, 3, 5, and 7 d were evaluated. Data were analyzed statistically using the Kruskal-Walis, Mann-Whitney-U, one-way analysis of variance, and chi-square tests (p=0.05). Results: Continuous rotation resulted in more pain at Day 1 when compared with the reciprocating groups (360° CCW – 30° CW and 270° CCW – 30° C) (p<0.05). Conclusions: Continuous rotation resulted in more postoperative pain at Day 1 than in reciprocating groups, and thereafter no significant pain was found among the groups.

Cyclic fatigue resistance of different continuous rotation and reciprocating endodontic systems.

Objective: The objective of this study is to compare the cyclic fatigue resistance of nine types of endodontic instruments of nickel–titanium. Materials and Methods: Five files of 25 mm of length of each group: Reciproc (RC) R25; WaveOne (WO) Primary; Unicone (UC) L25 25/0.06; K3XF 25/0.06; ProTaper Universal F2 (PTF2); ProTaper Next X2 (PTX2); Mtwo 25/0.06; BioRaCe 25/0.06; One Shape L25 25/0.06 were subjected to a cyclic fatigue resistance test on a mechanical apparatus. The mean fracture time was analyzed statistically by one-way analysis of variance and Tukey’s honest significant difference post hoc test, with significance set at P < 0.05. Conclusion: It was observed that the groups PTX2, RC, R25, UC L25 25/0.06, and WO Primary presented greater cyclic fracture resistance than the other groups (P < 0.001).

Influence of Apical Preparation Size and Working Length on Debris Extrusion

Abstract The aim of this study was to quantitatively evaluate the amount of apically extruded debris by single-file reciprocating instruments with different working lengths and apical preparation sizes. Eighty human single-rooted mandibular incisors were used and conventional access cavities were prepared. Then, the specimens were divided into four groups (n=20), according to root canal instrumentation: Reciproc size 25, .08 taper and Reciproc size 40, .06 taper instruments were used at the foramen; Reciproc size 25, .08 taper and Reciproc size 40, .06 taper instruments were used 1 mm short of the foramen. Distilled water was used as an irrigant and the apically extruded debris were collected in pre-weighted glass vials and dried afterwards. The mean weight of debris was weighed with a microbalance and statistically analyzed using one-way analysis of variance and the post hoc Tukey multiple comparison test (p<0.05). The results showed that all experimental groups were associated with debris extrusion. No significant difference was found in the amount of apically extruded debris among all experimental groups (p>0.05). The present study demonstrated that the working length and the apical preparation size did not have a significant effect on debris extrusion when performing single-file reciprocating instrumentation.

Resumo Este estudo avaliou quantitativamente a quantidade de material extruído apicalmente pela instrumentação com lima única reciprocante, aplicando diferentes comprimentos de trabalho e tamanhos de preparo apical. Para a análise de extrusão foram utilizados oitenta incisivos inferiores unirradiculares humanos. Cavidades de acesso convencionais foram preparadas e os espécimes foram divididos em quatro grupos (n=20), de acordo com o tipo de instrumentação do canal: Reciproc 25, 0.08 e Reciproc 40, 0.06 foram utilizadas na instrumentação até o forame; Reciproc tamanho 25, 0.08 e Reciproc 40, 0,06 foram utilizadas na instrumentação até 1 mm aquém do forame. Água destilada foi empregada como irrigante e o material extruído apicalmente foi coletado em frascos de vidro já pesados e posteriormente submetidos a secagem. O peso médio de detritos foi avaliado com uma microbalança de precisão e os dados submetidos a ANOVA e teste Tukey (p<0,05). Todos os grupos experimentais foram associados à extrusão de debris. Nenhuma diferença significativa foi encontrada na quantidade de material extruído apicalmente entre os grupos (p>0,05). Este estudo demonstrou que o comprimento de trabalho e o tamanho do preparo apical não geraram efeito significativo sobre a extrusão de debris durante a instrumentação reciprocante.

Safe Mechanical Preparation with Reciprocation Movement without Glide Path Creation: Result from a Pool of 673 Root Canals

Abstract The aim of the present study was to prospectively assess the frequency of teeth in which the Reciproc instruments were able to reach the full working length (WL). This case series study enrolled 277 consecutive teeth requiring primary endodontic treatment performed with the Reciproc system (VDW) without a previous glide path by 3 experienced endodontists. Instruments R25, R40 or R50 were selected, respectively, for narrow, medium and large canals, according to the preoperative radiographs, as per manufacturer recommendation. Canals were instrumented and classified as reaching the full WL (RFWL) and not reaching the full WL (NRFWL), according to the ability of the Reciproc instrument to reach without a glide path the full electronically determined WL. Finally, canals were filled using a single matched cone technique. Pearson's squared-chi test compared the frequency distributions of canals classified as RFWL and NRFWL. From a total pool of 673 root canals, Reciproc instruments reached the FWL in 96.28% of cases and 3 fractures occurred. For narrow canals the percentage of RFWL was 95.37% with 3 fractures. For medium and large canals, the R40 or R50 instruments reached the FWL in 98.51% and 97.62% of the cases respectively, with no fracture. Enlarging of root canals using the Reciproc instruments up to the FWL without a glide path is successful in a great percentage of cases. This case series suggests the possibility of using a single instrument to enlarge the root canal space of teeth by a simpler approach without an a prioriglide path procedure.

Resumo O objetivo do presente estudo foi avaliar prospectivamente a frequência de dentes em que os instrumentos Reciproc foram capazes de alcançar o comprimento de trabalho (CT) completo. Este estudo com série de casos envolveu 277 dentes consecutivos que necessitavam de tratamento endodôntico primário realizado com o sistema Reciproc (VDW) sem a realização de uma via de penetração inicial (glide path) prévio por 3 endodontistas experientes. Instrumentos R25, R40 ou R50 foram selecionados, respectivamente, para canais estreitos, médios e largos, de acordo com as radiografias pré-operatórias, seguindo a recomendação do fabricante. Os canais foram instrumentados e classificados como atingindo o WL completo (ACTC) e de não atingindo o WL completo (NACTC), de acordo com a capacidade do instrumento Reciproc de alcançar o CT completo determinado eletronicamente, sem a realização de glide path. Finalmente, os canais foram preenchidos usando a técnica de obturação de cone único. O teste de qui-quadrado de Pearson comparou a frequência das distribuições de canais classificados como ACTC e NACTC. A partir de um pool total de 673 canais radiculares, instrumentos Reciproc atingiram o CTC em 96,28% dos casos e 3 fraturas ocorreram. Para canais estreitos, a percentagem de ACTC foi 95,37% com 3 fraturas. Para canais médios e largos, os instrumentos R40 e R50 atingiram o CTC em 98,51% e 97,62% dos casos, respectivamente, sem fratura. Ampliação dos canais radiculares utilizando os instrumentos Reciproc até o CTC sem a realização de glide pathfoi bem sucedida em uma grande porcentagem dos casos. Esta série de casos sugere a possibilidade de utilizar um único instrumento para ampliar o espaço do canal radicular usando uma abordagem mais simples, sem um procedimento prévio deglide path.

Comparision of the shaping and cleaning ability of Reciproc,OneShape and ProTaper rotary instrument in oval-shaped canal of extracted teeth / 实用口腔医学杂志

Objective:To investigate the shaping and cleaning ability of Reciproc(RE),OneShape(OS)and ProTaper(PT)in oval-shaped root canal preparation.Methods:The canals of 57 distal roots of mandibular first molars were randomly divided into 3 groups and prepared by RE,OS and PT respectively.The preparation time was recorded.After instrumentation,all root canal walls were examined under SEMand evaluated by scores of debris and smear layer.The 3D data and images of the roots of pre-and post-preparation were con-structed by Micro-CT scanning.Results:Group RE and OS showed lower scores of debris and smear layer than those in group PT at the apical level(P <0.05),and less preparation time (P <0.05).Before and after preparation,the changes of root canal morphological pa-rameters (including volume,surface,area,major diameter and minor diameter)in OS group were less than those in group RE and PT(P<0.05).The changes of canal curvature in group PT was larger than that in group RE and OS (P <0.05).Conclusion:RE and OS are more effective than PT in debridement and faster in root canal preparation.RE and OS can maintain the centering of original canal better than PT in the apical part of the root canal.The shaping ability of OS is weaker than that of RE and PT.

Análise em Micro-CT da obturação dos canais radiculares realizada com os sistemas GuttaFusion® e Thermafil® e técnica de Schilder em protótipos de molares / MicroCT filing ability analysis of GuttaFusion®, Thermafil® and Schilder's technique on prototyping molar replicas

O presente trabalho teve por objetivo investigar quantitativamente a obturação dos canais radiculares realizada em réplicas de molares em resina, usando GuttaFusion®, Thermafil® e a técnica da condensação vertical aquecida de Schilder. Vinte e um molares TrueTooth™ Replica 18-002 foram utilizados e os canais das raízes mesiais instrumentados com Reciproc® R40. Cada espécime foi escaneado em microtomógrafo computadorizado (SkyScan 1173; Bruker-microCT, Kontich, Bélgica) após o preparo químico-cirúrgico e após a obturação dos canais radiculares. Os dentes foram divididos em três grupos: Grupo I ­ GuttaFusion®; Grupo II ­ Schilder; Grupo III ­ Thermafil®. Então as amostras foram microtomografadas no equipamento operado a 50 kV e 800 mA (filtros de 0.5-mm). As imagens de cada amostra foram reconstruídas no programa NRecon v.1.6.3 (Bruker-microCT, Kontich, Bélgica), gerando secções axiais de suas estruturas interiores. Para cada dente, a avaliação foi calculada ao longo de toda a extensão do canal em aproximadamente 500 fatias por amostra. Foi produzida uma imagem tridimensional (volume/ área de superfície) de cada espécime, no programa ImageJ (National Institutes of Health, Bethesda, Maryland, Estados Unidos). A partir das imagens reconstruídas, o volume da obturação foi calculado. Os dados da amostra dos canais obturados foram calculados sobre os dados dos canais instrumentados e analisados estatisticamente com os testes Kruskal-Wallis e pelo teste Mann-Whitney para comparar par a par. Os dados obtidos demonstraram que há diferença estatisticamente significante entre os grupos (p < 0,05). O grupo Thermafil® demonstrou possuir uma maior capacidade de preenchimento do espaço correspondente ao canal radicular, quando comparado ao grupo GuttaFusion® e ao grupo Schilder. Porém, não há evidência estatística que demonstre diferença entre os grupos GuttaFusion® e Schilder

The aim of this study was to investigate quantitatively the filling of root canals performed on replicas of molars, using GuttaFusion®, Thermafil® and Schilder's warm vertical condensation technique. Twenty-one molars TrueTooth™ Replica 18-002 (DELendo, Santa Barbara, California) were used and the mesial root canals instrumented with Reciproc® R40. Each specimen was submited to a µCT scan after chemical-surgical preparation and after the filling of root canals. The teeth were divided into three groups: Group I ­GuttaFusion®; Group II ­Schilder; Group III - Thermafil®. Then the samples were microscanned (SkyScan 1173; Bruker-microCT, Kontich, Belgium) operated at 50 kV and 800 mA (0.5-mm filter). Images of each sample were reconstructed in NRecon v.1.6.3 software (Bruker-microCT, Kontich, Belgium), generating axial sections of their internal structures. For each tooth, the evaluation was calculated over the entire root canal length of approximately 500 slices per sample. Then the three-dimensional image was produced (volume, surface area) of each specimen at the ImageJ software (National Institutes of Health, Bethesda, Maryland, USA), and reconstructed images and calculated the volume of the shutter. The sample data of root canals were calculated based on data from instrumented canals and statistically analyzed with Kruskal-Wallis test and Mann-Whitney test to compare pairwise. The data showed a statistically significant difference between groups (p <0.05). The Thermafil® group has demonstrated greater filling capacity of the space corresponding to the root canal compared to GuttaFusion® group and Schilder group. However, there is no statistical evidence that demonstrates the difference between GuttaFusion® and Schilder groups.