Meant to make a difference, the clinical experience of minimally invasive endodontics with the self-adjusting file system in India.

The vital steps in any endodontic treatment are thorough mechanical shaping and chemical cleaning followed by obtaining a fluid tight impervious seal by an inert obturating material. For the past two decades, introduction and use of rotary nickel‑titanium (Ni‑Ti) files have changed our concepts of endodontic treatment from conventional to contemporary. They have reported good success rates, but still have many drawbacks. The Self‑Adjusting File (SAF) introduces a new era in endodontics by performing the vital steps of shaping and cleaning simultaneously. The SAF is a hollow file in design that adapts itself three‑dimensionally to the root canal and is a single file system, made up of Ni‑Ti lattice. The case series presented in the paper report the clinical experience, while treating primary endodontic cases with the SAF system in India.

Efectividad de la instrumentación del conducto radicular realizado manualmente y con el sistema de rotación alternada / Effectiveness of root canal instrumentation and hand made with alternating system rotation

Este trabajo evaluó "in vitro" la efectividad de la instrumentación del conducto radicular realizado manualmente y con el contra-ángulo de rotación alternada Tep 10-R (NSK) empleando limas Flex-R (acero inoxidable) y Onix-R (NiTi). Fue utilizada la raíz mesio-vestibular de 48 dientes molares superiores humanos dividido en cuatro grupos. La preparación biomecánica del conducto radicular de los dientes en los grupos 1 y 2 fue realizada con la técnica manual utilizando limas Flex-R y Onix-R respectivamente, y en los grupos 3 y 4 con el contra ángulo Tep 10-R utilizando los mismos tipos de limas del grupos 1 y 2. La instrumentación del conducto radicular fue realizada con técnica de ampliación reversa, evaluando la capacidad de mantener la curvatura original del conducto radicular en nivel apical, el tiempo requerido para la instrumentación y el índice de fractura de los instrumentos. Desvio apical se analizó con el método de la plataforma radiográfica. Los resultados no mostraron diferencias estadísticas significativas (p>0,05) a pesar de haber sido observados dos desvíos apical en el grupo donde se utilizó las limas Flex-R. El tiempo necesario para la instrumentación del canal radicular utilizando cualquier tipo de instrumento en cualquier técnica, y el número de fractura de instrumentos no mostró ninguna diferencia estadística significante (p>0.05)...

The aim of this study was to compare "in vitro" the efficiency of root canal preparation performed manually and with an automated reciprocating (alternated) handpiece Tep 10-R (NSK) with Flex-R (stainless steel) and Onix-R (NiTi) files in a crow-down technique. Mesio-buccal roots of 48 maxillary molars were divided into four groups. The canals from groups 1 and 2 were performed manually technique with Flex-R (stainless steel) and Onix-R (niti) files respectively, and canals from groups 3 and 4 with the automated reciprocating handpiece Tep 10-R with the same files than groups 1 and 2. Apical deviation was analyzed through the radiographic platform method and the results showed no significant statistical difference (p>0.05), although two deviations were detected in the groups where stainless steel instruments were employed. The time necessary for root canal preparation using both instruments and techniques and instrument's fracture showed no statistical difference (p>0.05)...

Influence of apical foramen lateral opening and file size on cemental canal instrumentation

Since instrumentation of the apical foramen has been suggested for cleaning and disinfection of the cemental canal, selection of the file size and position of the apical foramen have challenging steps. This study analyzed the influence of apical foramen lateral opening and file size can exert on cemental canal instrumentation. Thirty-four human maxillary central incisors were divided in two groups: Group 1 (n=17), without flaring, and Group 2 (n=17), with flaring with LA Axxess burs. K-files of increasing diameters were progressively inserted into the canal until binding at the apical foramen was achieved and tips were visible and bonded with ethyl cyanoacrylate adhesive. Roots/files set were cross-sectioned 5 mm from the apex. Apices were examined by scanning electron microscopy at ×140 and digital images were captured. Data were analyzed statistically by Student’s t test and Fisher’s exact test at 5% significance level. SEM micrographs showed that 19 (56%) apical foramina emerged laterally to the root apex, whereas 15 (44%) coincided with it. Significantly more difficulty to reach the apical foramen was noted in Group 2. Results suggest that the larger the foraminal file size, the more difficult the apical foramen instrumentation may be in laterally emerged cemental canals.

Tendo em vista que a instrumentação do forame apical tem sido sugerida para a limpeza e desinfecção do canal cementário, a seleção do calibre do instrumento e a posição do forame apical representam passos desafiantes. Este estudo analisou a influência que a saída lateral do forame apical e o calibre do instrumento podem exercer na instrumentação do canal cementário. Trinta e quatro incisivos centrais superiores foram divididos em dois grupos: Grupo 1 (n=17), sem preparo cervical, e Grupo 2 (n=17), com preparo cervical com brocas LA Axxess. Limas K com aumentos de diâmetro foram progressivamente inseridas no canal até ajustar no forame apical e as pontas ficarem visíveis e foram fixadas com adesivo de etil cianoacrilato. Os conjuntos raízes/limas foram seccionados transversalmente a 5 mm aquém do ápice. Os ápices foram examinados por microscopia eletrônica de varredura com aumento de 140x e imagens digitais foram capturadas. Os dados foram examinados estatisticamente pelo teste t de Student e teste exato de Fischer com nível de significância de 5%. A microscopia eletrônica de varredura mostrou que 19 (56%) dos forames apicais saíram lateralmente em relação ao ápice radicular, enquanto que 15 (44%) coincidiram com ele. Dificuldade significantemente maior para chegar ao forame apical foi observada no Grupo 2. Os resultados sugerem que quanto mais calibroso for o instrumento foraminal, mais difícil poderá ser a instrumentação do forame apical em canais cementários que apresentam saída lateral.

Cyclic fatigue of the sodium hypochlorite treated and/or steam autoclaved nickel-titanium endodontic files / 대한치과보존학회지

The purpose of this study was to determine the effect of sodium hypochlorite and steam autoclaving on the cyclic fatigue of nickel-titanium endodontic files. Two types of files with a .06 taper and #30 were used, K3(R) (SybronEndo, Glendora, California, USA) and Hero642(R) (Micro-Mega, Besancon, France). The files were divided into 6 experimental groups containing 10 files each group depending the soaking time in 6% sodium hypochlorite solution and number of cycles of steam autoclave. After sterilization, a cyclic fatigue test was performed on each file, and the fracture time was recorded in seconds. The control group underwent the cyclic fatigue test only. After the test, the surface characteristics of the files were observed using scanning electron microscopy (SEM). All groups containing the Hero 642(R) files showed a similar cyclic fatigue fracture time. However, the cyclic fatigue fracture time with the K3(R) files was significantly shorter in groups which were treated with sodium hypochlorite than in the control group (P < 0.05). SEM revealed both Hero642(R) and K3(R) files to have significant corrosion on the file surface in groups treated with sodium hypochlorite, compared with the sharp and regular blades of the control group. K3(R) files showed more corrosion than the Hero642(R) files. Bluntness of the blades of the K3(R) file was observed in groups treated with steam autoclave. Although there was no obvious destruction on the surface of steam autoclaved Hero642(R) files, slight bluntness was observed. Sterilizing with a steam autoclave is much less destructive to K3(R) files than sodium hypochlorite. The longer time exposed to sodium hypochlorite, the more destructive pattern was shown on the blades of the files. Therefore, when using sodium hypochlorite solution, the exposure time should be as short as possible in order to prevent corrosion and increase the cyclic fatigue fracture time.