RESUMEN
The purpose of this study was to analyze the influence of Chitosan 0.2% in various final cleaning methods on the bond strength of fiberglass post (FP) to intrarradicular dentin. Ninety bovine incisors were sectioned to obtain root remnants measuring 18 mm in length. The roots were divided: G1: EDTA 17%; G2: EDTA 17% + PUI; G3: EDTA 17% + EA; G4: EDTA 17% + XPF; G5: Chitosan 2%; G6: Chitosan 2% + PUI; G7: Chitosan 2% + EA; G8: Chitosan 2% +XPF. After carrying out the cleaning methods, the posts were installed, and the root was cleaved to generate two disks from each root third. Bond strength values (MPa) obtained from the micro push-out test data were assessed by using Kruskal-Wallis and Dwass-Steel-Critchlow-Fligner tests for multiple comparisons (α = 5%). Differences were observed in the cervical third between G1 and G8 (p = 0.038), G4 and G8 (p = 0.003), G6 and G8 (p = 0.049), and Control and G8 (p = 0.019). The final cleaning method influenced the adhesion strength of cemented FP to intrarradicular dentin. Chitosan 0.2% + XPF positively influenced adhesion strength, with the highest values in the cervical third.
RESUMEN
Objetivo: Analisar falhas de fabricação na superfície ativa de diferentes instrumentos de níquel-titânio por meio da microscopia eletrônica de varredura. Material e método: Foram analisados um total de 33 instrumentos distribuídos em dois grupos de acordo com a procedência: G1 - Sistema Protaper Next® sendo analisados 03 kits de 05 instrumentos de NiTi cada (X1 17/0.04; X2 25/0.06; X3 30/0.07; X4 40/0.06; X5 50.0.06); G2 - Sistema Biorace®, sendo analisados 03 kits constituído de 06 instrumentos cada (BR0 25/0.08; BR1 15/0.05; BR2 25/0.04; BR3 25/0.06; BR4 35/0.04; BR5 40/0.04); Os instrumentos foram retirados da embalagem e direcionados para a análise de falhas na superfície ativa em imagens de microscopia eletrônica de varredura. Para determinação das falhas na superfície do instrumento, dividiu-se a parte ativa de 16mm em 14 partes de 2,55mm cada (S1-S7), nominadas seguimentos de 1 ao 7. Resultados: As frequências de defeitos encontradas para cada segmento dos instrumentos analisados foram cruzadas com os dados do número do instrumento por meio do teste do Qui-quadrado. Houve influência de uma variável sobre a outra apenas quando se analisou o segmento 1 do kit Protaper Next (p=0,005). O instrumento X4 mostrou um número maior de falhas que os demais instrumentos. A relação entre o número de defeitos observados nos diferentes sistemas de instrumentos foi avaliada pelo teste do Qui-quadrado. Não foram encontradas diferenças estatisticamente significantes entre Biorace e Protaper Next (p>0,05). Conclusão: Ambos os instrumentos dos grupos analisados apresentaram algum tipo de falha na superfície ativa.
Aim: To analyze manufacturing failures in the active surface of different nickel-titanium instruments by of scanning electron microscopy. Material and method: A total of 33 instruments distributed in two groups according to the provenance were analyzed: G1 - Protaper Next® System and 03 kits of 05 NiTi instruments were analyzed (X1 - 17 / 0.04; X2 - 25 / 0.06; X3- 30 / 0.07; X4-40 / 0.06; X5-50.0.06); G2 - Biorace® system, with three kits consisting of 06 instruments each (BR0 - 25 / 0.08; BR1 - 15 / 0.05; BR2 - 25 / 0.04; BR3 - 25 / 0.06; BR4 - 35 / 0.04); The instruments were removed and analysis of active surface defects in scanning electron microscopy images. In order to determine the defects on the instrument surface, the active part of 16mm was divided into 14 parts of 2,55mm each (S1-S7), named sequences from 1 to 7. Results: The frequencies of defects found for each segment of instruments were cross-checked with the instrument number data using the chi-square test. There was influence of one variable on the other only when analyzing Segment 1 of the Protaper Next Kit (p = 0.005). Instrument X4 showed more failures than other instruments. The relationship between the number of defects observed in the different instrument systems was evaluated by the chi-square test. No statistically significant differences were found between Biorace and Protaper Next (p> 0.05). Conclusion: Both instruments of the analyzed groups presented some type of fault on the active surface.