In Vitro Evaluation of a Recently Developed Rotary File: AF Rotary / Avaliação in vitro de um arquivo rotativo desenvolvido recentemente: AF Rotary

Objective: Aim of the present study is to evaluate mechanical properties of a newly developed rotary file, AF Rotary (Fanta Dental, Shanghai, China), and to compare these features with a worldwide spread rotary file, Protaper Gold F2 (PTG F2; Dentsply Maillefer, Ballaigues, Switzerland). Material and Methods: 60 AF Rotary 25.06 and 60 PTG F2 were divided in three groups of 20 files each. A group underwent to cyclic fatigue resistance tests, second group underwent to torsional resistance tests, third group underwent to bending tests. The statistical analysis was performed using t student test with significance level set at 95% (p < 0.05). Results: AF Rotary showed significantly higher torsional resistance and cyclic fatigue resistance (p < 0.05) when compared to the PTG F2. AF Rotary also showed significantly lower bending resistance (p < 0.05) when compared to the PTG F2. Conclusion: Therefore, within the limitations of this study, the results show better performances for AF Rotary compared to PTG F2 regarding the cyclic fatigue test, the torsional test and the bending test. Since the PTG F2 is a commonly used and widely investigated instrument it could be possible to state that the AF Rotary exhibits remarkable in vitro performances. (AU)

Objetivo: O objetivo do presente estudo é avaliar as propriedades mecânicas de uma lima rotativa recém-desenvolvida, AF Rotary (Fanta Dental, Shanghai, China), e comparar essas características com uma lima rotativa mundialmente difundida, Protaper Gold F2 (PTG F2; Dentsply Maillefer, Ballaigues, Suíça). Material e Métodos: 60 AF Rotary 25.06 e 60 PTG F2 foram divididos em três grupos de 20 arquivos cada. Um grupo foi submetido a testes de resistência à fadiga cíclica, o segundo grupo foi submetido a testes de resistência à torção, o terceiro grupo foi submetido a testes de flexão. A análise estatística foi realizada por meio do teste t student com nível de significância de 95% (p <0,05). Resultados: AF Rotary apresentou resistência torcional e resistência à fadiga cíclica significativamente maiores (p <0,05) quando comparado ao PTG F2. AF Rotary também apresentou resistência à flexão significativamente menor (p <0,05) quando comparado ao PTG F2. Conclusão: Portanto, dentro das limitações deste estudo, os resultados mostram melhores desempenhos do AF Rotary em relação ao PTG F2 no que diz respeito ao teste de fadiga cíclica, ao teste de torção e ao teste de flexão. Uma vez que o PTG F2 é um instrumento comumente usado e amplamente investigado, pode-se afirmar que o AF Rotary exibe desempenhos in vitro notáveis. (AU)

Comparison of Application Effect of NiTi Rotary Instruments and Hand NiTi Enlarging File in Children with Root Canal Therapy / 中山大学学报(医学科学版)

[Objective]To study effect of pain and stress response of NiTi rotary instrument for children with root canal therapy , and analyzed possible mechanisms.[Methods]60 cases(60 teeth)children with Dental pulp disease or root tip disease by root canal therapy from March 2015 to March 2017 were divided into observation group and control group. The control group used Hand NiTi en-larging file,observation group used NiTi rotary instruments,then root canal preparation,stress response,pain,filling effect and long-term efficacy were compared between two groups.[Result]The observation group root canal preparation time were significantly shorter than control group(P < 0.01),root canal deviation etc morphological changes(6.67%)was significantly lower than control group(26.67%,P < 0.05);gingival crevicular fluid TNF-α,IL-6,IL-1β were significantly lower than control group(P < 0.05, P < 0.01). In root canal preparation,after root canal preparation,pain rate were significantly lower than control group(10.00% vs 33.33%,3.33% vs 23.33%,P < 0.05);1 week after surgery,just fill rate(93.33%)was significantly higher than control group (70.00%,P<0.05). Followed up 6 months,root canal success rate(90.00%)was significantly higher than control group(66.67%, P<0.05).[Conclusion]NiTi rotary instruments help to reduce the pain in children with root canal,improve clinical efficacy,May be related to inhibition of surgical stress response.