Comparación entre los sistemas manual de limas de acero inoxidable y el rotatorio de limas de níquel titanio, en la conformación de conductos radiculares curvos in vitro / Comparison between the manual system of stainless steel files and the rotating system of nickel titanium files in the conformation of curved radicular ducts in vitro

Resumen Introducción: Estudio experimental donde se procuró comparar el efecto del sistema manual y del rotatorio sobre la conformación de conductos curvos. Metodología: Una muestra de 40 raíces mesiales de primeras molares inferiores fue aleatorizada en dos grupos iguales: grupos sistema manual de limas K y sistema rotatorio FGK Race®. Se comparó el radio de la curvatura final vs. el inicial mediante el programa Autocat 2015. Se empleó la prueba t con significancia de 0,05. Resultados: El radio de la curvatura varió de manera significativa, tanto para sistema manual como para el rotatorio FGK Race® (p=0,0001 y p=0,0013, respectivamente). Además, el sistema manual produjo mayor variación en el radio de la curvatura al compararlo con el sistema rotatorio 2,23 mm vs. 1,27 mm respectivamente; p=0,13. Conclusiones: Ambos sistemas produjeron modificación en la conformación de los conductos mesiales; sin embargo, en la comparación entre ambos dichas diferencias no fueron significativas.

Abstract Introduction: An experimental study was carried out to compare the effect of the manual system and the rotary system on the conformation of curved conduits. Methodology: A sample of 40 mesial roots of lower first molars was randomized into two equal groups: group manual system of K-files and group rotary system FGK Race®. The radius of the final curvature vs. the initial curvature was compared using the Autocat 2015 program. The t-test with a significance of 0.05 was used. Results: The curvature radius varied significantly for both the manual system and the rotary FGK Race® (p = 0.0001 and p = 0.0013, respectively). In addition, the manual system produced greater variation in the radius of the curvature when compared to the rotary system 2.23mm vs. 1.27mm respectively; p = 0.13. Conclusion: Both systems produced modification on the conformation of the conduits of the mesial roots; however, in the comparison between both systems said differences were not significant.

Precisão e confiabilidade de um localizador apical na odontometria de molares inferiores: estudo in vitro / Accuracy and reliability of an apex locator for working length determination of lower molars: an in vitro study

O presente estudo in vitro teve por objetivo avaliar a precisão e a confibialidade de um modelo de localizador apical eletrônico (LAE) na obtenção do comprimento de trabalho (CT) em molares inferiores. Após adequado acesso endodôntico e manobras iniciais de exploração em 20 dentes, mediu-se com uma lima K # 10 o comprimento dos condutos mésio-vestibular (MV) e distal (D) até o forame apical, subtraindo-se 1 mm (CT1), tendo como referências externas as cúspides mésio-vestibular e disto-vestibular, respectivamente. Os dentes foram fixados em recipientes plásticos contendo alginato procedendo-se as medidas eletrônicas com o LAE Novapex (Fórum,Israel). Limas K # 10 foram inseridas nos canais MV e D até que os instrumentos atingissem a marca 0 no visor do aparelho e posteriormente realizava-se o recuo até a marca 1, ajustando-se os cursores nas mesmas referências externas do CT1. As mensurações com o LAE foram realizadas em triplicata, adotando-se a média das medidas, por dois operadores calibrados, um estudante de gradução (CT2) e um especialista em endodontia (CT3). O coeficiente de correlação linear de Pearson revelou alta concorcândia inter?operadores e intraoperadores. Para comparação do CT1, CT2 e CT3 foi aplicado o Teste t de Student para amostras pareadas (p < 0,05), que não mostrou diferenças significativas entre todas as medidas odontométricas para os canais radiculares MV (p = 0,22 ) e D (p = 0,94). Portanto, o LAE testado mostrou-se preciso e confiável na determinação da odontometria de molares inferiores.

The aim of this in vitro study was to evaluate the accuracy and reliability of an electronic apex locator (EAL) in the determination of the working length (WL) of lower molars. After appropriate endodontic access and exploration in 20 teeth, it was measured with a size 10 K-file the actual canal length (AL) of the mesio-buccal (MB) and distal (D) root canals until the apical foramen. Next, it was subtracted 1mm of the AL (WL1), taking as coronal references the vertex of the mesio-buccal and disto-buccal cusps. The teeth were embedded in an alginate model and electronic tooth length measurements were carried out using the EAL Novapex (Fórum, Israel). A 10 K-type file was inserted down the MB and D canals until EAL indicated that the file had reached the apex retreating until the mark 1. The cursors were adjusted in the same external references of WL1. The eletronic measurements were obtained by two operators, a graduate student (WL2) and a specialist (WL3). Three measurements were taken and an average recorded. The coefficient of Pearson revealed high concordance level inter-operators and intra-operators. For comparison of WL1, WL2 and WL3 the test t of Student was applied (p < 0,05). There was no statistically significant difference between all the measures for MB (p = 0,22) and D (p = 0,94) root canals. Therefore, the tested EAL was accurate and reliable in the determination of the WL of lower molars.