Instrumentación rotatoria en endodoncia: reporte de casos clínicos / Rotary instrumentation in endodontics: clinical cases report

Los recientes avances en endodoncia de los últimos años, como la introducción de instrumentación rotatoria con limas de Niquel Titanio (NiTi), han simplificado el proceso del tratamiento, mejorando el éxito a largo plazo en términos de tiempo, efectividad y reducción de riesgos, comparados con la instrumentación manual con limas de acero inoxidable. Sin embargo, para algunos clínicos resulta difícil seleccionar el sistema rotatorio NiTi más apropiado, debido a la numerosa cantidad de instrumentos que conforman los diferentes sistemas existentes en el mercado. El presente reporte, basado en casos clínicos de la práctica diaria, tiene como objetivo mostrar, analizar y destacar la posibilidad de realizar tratamientos endodónticos predecibles con la técnica corono apical utilizando el sistema ProTaper Universal.

Advances in recent years in endodontics, such introduction of rotary Niquel Titanium (NiTi) instrumentation have simplified the treatment process and improved the long term success in terms of procedural time, accuracy, and risk reduction compared with the previously used, manual, stainless steel files. However, selecting the most appropriate NiTi system remains difficult for clinicians because of the large number of NiTi rotary instruments available nowadays on the market. This paper aims to show, analyze and emphasize, on the basis of every day clinical practice, the possibility of realizing predictability root canal preparations with the crown down technique of ProTaper Universal system.

A survey of experience-based preference of Nickel-Titanium rotary files and incidence of fracture among general dentists

OBJECTIVES: The purpose was to investigate the preference and usage technique of NiTi rotary instruments and to retrieve data on the frequency of re-use and the estimated incidence of file separation in the clinical practice among general dentists. MATERIALS AND METHODS: A survey was disseminated via e-mail and on-site to 673 general dentists. The correlation between the operator's experience or preferred technique and frequency of re-use or incidence of file fracture was assessed. RESULTS: A total of 348 dentists (51.7%) responded. The most frequently used NiTi instruments was ProFile (39.8%) followed by ProTaper. The most preferred preparation technique was crown-down (44.6%). 54.3% of the respondents re-used NiTi files more than 10 times. There was a significant correlation between experience with NiTi files and the number of reuses (p = 0.0025). 54.6% of the respondents estimated experiencing file separation less than 5 times per year. The frequency of separation was significantly correlated with the instrumentation technique (p = 0.0003). CONCLUSIONS: A large number of general dentists in Korea prefer to re-use NiTi rotary files. As their experience with NiTi files increased, the number of re-uses increased, while the frequency of breakage decreased. Operators who adopt the hybrid technique showed less tendency of separation even with the increased number of re-use.

Apical extrusion of debris after hand, engine-driven reciprocating and continuous preparation / Extrusão apical de debris após o preparo manual e mecanizado oscilatório e contínuo

Purpose: This in vitro study assessed the amount of debris extruded apically after preparation with different techniques. Methods: Sixty healthy, extracted, human mandibular incisors were randomly divided into 3 groups: Group A - hand crown-down technique; Group B - crown-down technique with engine-driven rotary reciprocating instruments; Group C - Protaper: engine-driven continuous rotary instrumentation. The roots were immersed in 2.3 mL of distilled water. After preparation, the water in each tube was filtered to collect solid material extruded, and the filters were weighed using a precision scale. Data were analyzed by Kolmogorov-Smirnov and Kruskal-Wallis tests at the 0.05 level of significance. Results: The statistical analysis showed that group C had significantly higher values of debris than groups A and B. Conclusion: The instrumentation using a continuous rotary technique, Protaper, produced greater apical extrusion than the hand and engine-driven crown-down techniques. The direction of instrumentation, whether cervical-apical or apical-cervical, seems to be a more important factor influencing apical extrusion than whether the instrumentation was performed by hand or was engine-driven.

Objetivo: Este estudo, in vitro, avaliou a quantidade de extrusão apical de "debris", após o preparo químico-mecânico do canal radicular, utilizando diferentes técnicas. Metodologia: Sessenta incisivos inferiores humanos hígidos foram aleatoriamente divididos em três grupos: Grupo A: técnica coroa-ápice manual; Grupo B: técnica coroa-ápice mecanizada com sistema de rotação oscilatória; Grupo C: Protaper, técnica mecanizada com sistema derotação contínua. As raízes foram imersas em 2,3 mL de água destilada. Após os preparos, a água destilada de cada amostra foi filtrada, e o filtro de papel, contendo o material sólido extruído, foi pesado em uma balança analítica de precisão. Os dados foram analisados estatisticamente pelos testes Kolmogorov-Smirnov e Kruskal-Wallis ao nível de significância de 0,05. Resultados: A análise estatística demonstrou que o grupo C apresentou valores superiores de "debris" do que os grupos A e B. Conclusão: A técnica rotatória contínua com Pro-taper produziu maior quantidade de extrusão apical do que as técnicas coroa-ápice manual e mecanizada com sistema de rotação oscilatória. A direção da instrumentação, se cérvico-apical ou ápico-cervical, parece ser o fator mais determinante na extrusão de "debris" independente desta ser realizada manual ou mecanizada.

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.