ABSTRACT
Este estudo envolve um estudo in sílico, um ensaio clínico randomizado e duas revisões sistemáticas com o objetivo de compreender a influência dos pinos de fibra (PF) na resistência à fratura de dentes tratados endodonticamente e restaurados e também, avaliar o efeito de tratamentos químicos dentinários na resistência de união da cimentação do PF na dentina intrarradicular. Estudo in silico: seis modelos tridimensionais de incisivos centrais superiores foram projetados em um software de desenho e se diferenciaram de acordo com a presença ou ausência de PF de vidro e espessura das facetas diretas de resina composta (0,5, 0,7 e 1 mm). Foram transferidos para o software ANSYS 17.2, no qual movimentos funcionais foram simulados com carga de 100 N a 45º nas faces linguais. Os modelos com PF apresentaram melhor distribuição de tensões e menores valores de tensão máxima na região da dentina e faceta. Ensaio clínico randomizado: selecionou-se 50 pacientes com necessidade de faceta em um incisivo central ou lateral superior tratado endodonticamente. Foram divididos em dois grupos (n=25) de acordo com o uso ou não de PF de vidro. Após 6 e 12 meses do tratamento, avaliações clínicas e radiográficas em relação à presença e tipo de fratura, apontaram taxas de sucesso de 96% para o grupo sem PF e 100% para o grupo com PF, sem diferenças estatisticamente significativas. Revisão sistemática e metanálise: as bases de dados PubMed, Scopus, Web of Science, LILACS, BBO, Cochrane Library e Embase foram acessadas com a estratégia de busca definida de acordo com a pergunta: ' O uso de PF influencia na resistência à fratura de dentes anteriores tratados endodonticamente e restaurados, quando comparados com o não uso de PF? ' Foram incluídos 32 estudos in vitro. Após a metanálise, pode-se concluir que o uso de PF favoreceu a resistência à fratura dos dentes, principalmente para dentes com preparo para faceta e cavidades cervicais e os PF de vidro mostraram resultados mais satisfatórios. Revisão sistemática e metanálise em rede: as bases PubMed, Scopus, Web of Science, LILACS, BBO e Cochrane Library foram acessadas com a estratégia de busca definida de acordo com a pergunta: ' Tratamentos químicos da dentina intrarradicular afetam a força de união de PF em dentes tratados endodonticamente? ' Foram incluídos 61 estudos in vitro. Foi realizada a avaliação do risco de viés para estudos in vitro. Após a metanálise em rede e análise de SUCRA para cada estratégia de cimentação (adesivo autocondicionante, adesivo de condicionamento total e cimento autoadesivo), concluiu-se que os tratamentos químicos da dentina intrarradicular que melhoram a força de união da cimentação de PF são o acetato de etila para adesivos autocondicionantes, NaOCl em baixa concentração para adesivos de condicionamento total e extrato de semente de uva para cimentos autoadesivos(AU)
This study involves an in silico study, a randomized clinical trial, and two systematic reviews to understand the influence of fiber posts (FP) on fracture strength of endodontically treated and restored teeth and also to evaluate the effect of dentin chemical treatments on bond strength of FP cementation in intraradicular dentin. In silico study: six three-dimensional models of maxillary central incisors were designed in a CAD software and differed according to the presence or absence of glass FP and thickness of composite resin direct veneer (0.5, 0.7 and 1 mm). They were transferred to the ANSYS 17.2 software, in which functional movements were simulated with a load of 100N at 45º on the lingual surfaces. The models with glass FP showed better stress distribution and lower maximum stress values in the dentin and veneer region. Randomized clinical trial: 50 patients who needed veneer treatment of an endodontically treated central or lateral maxillary incisor were selected. They were divided into two groups (n=25) according to the use or not of glass FP. Direct composite resin veneers were performed for two groups. In the FP group, they were cemented with self-adhesive resin cement. Descriptive data of the population and restored teeth were collected. After 6 and 12 months of treatment, clinical and radiographic evaluations regarding the presence and type of fracture indicated success rates of 96% for the group without FP and 100% for the group with FP, with no statistically significant differences. Systematic review and meta-analysis: PubMed, Scopus, Web of Science, LILACS, BBO, Cochrane Library and Embase databases were accessed with the search strategy defined according to the question: "Does the use of FP influence on fracture strength of endodontically treated and restored anterior teeth when compared to non-use of fiber posts?" Thirty-two in vitro studies were included. Bias risk assessment was based on existing systematic reviews of in vitro studies. After the meta-analysis, it can be concluded that the use of FP favored the fracture resistance of teeth, especially for teeth with veneer preparation and cervical cavities and the glass FP showed more satisfactory results. Systematic review and network meta-analysis: PubMed, Scopus, Web of Science, LILACS, BBO and Cochrane Library databases were accessed with the search strategy defined according to the question: 'Do intraradicular dentin chemical pretreatments affect the bond strength of fiber posts for endodontically treated teeth?' Sixty-one in vitro studies were included. Bias risk assessment for in vitro studies was performed. After network meta-analysis and SUCRA analysis for each cementation strategy (self-etching adhesive, total etching adhesive and self-adhesive cement), it was concluded that the intraradicular dentin chemical treatments that improve the bond strength of FP cementation are ethyl acetate for self-etching adhesive, low concentration NaOCl for total etching adhesives and grape seed extract for selfadhesive cements(AU)
Subject(s)
Dental Veneers/trends , Post and Core Technique , Randomized Controlled Trial , Flexural Strength/drug effects , Systematic ReviewABSTRACT
El objetivo fue evaluar in vitro el efecto de la concentración y del tiempo de aplicación del ácido fluorhídrico sobre la rugosidad de la superficie y la resistencia a la fractura de la cerámica de Disilicato de litio de última generación. Se fabricaron 90 discos de cerámica IPS e.max press (14 mm diámetro, 1,2 mm espesor), mediante la técnica de inyección y posterior pulido. Se utilizaron 60 discos para evaluar la resistencia a la flexión biaxial mediante la prueba del pistón y las 3 esferas; se realizó un acondicionamiento con ácido fluorhídrico al 4,6% y al 9,5% durante 20, 40 y 60 segundos (10 discos por cada tiempo y concentración). Los 30 discos restantes se utilizaron para medir los valores de rugosidad superficial (Ra) con ácido fluorhídrico al 4,6% y al 9,5% durante 20, 40 y 60 segundos (5 discos por grupo) mediante microscopia óptica 3D, la cual permitió medir los valores de Rugosidad (Ra). Los datos fueron analizados mediante una prueba de ANOVA y Post- Hoc para determinar las diferencias significativas entre los grupos de estudio. Los valores promedio de la resistencia a la flexión biaxial en los grupos 1, 2 y 3 con la aplicación del ácido fluorhídrico al 4,6% y tiempos de 20, 40 y 60 fueron de 448,45±68,1 Mpa, 357,23±59,5 Mpa y 317,69±45,97 Mpa, respectivamente. Los valores en los grupos al 9,6% fueron de 365,40±46,93 Mpa, 334,38±40,75 Mpa y 348,83±79,39 Mpa. La resistencia a la flexión biaxial de la cerámica de disilicato de litio de última generación se ve afectada por la concentración y el tiempo de aplicación del ácido fluorhídrico. A mayor tiempo de aplicación y concentración del ácido fluorhídrico, menor la resistencia del material. El efecto de la concentración del ácido fluorhídrico y el tiempo de aplicación sobre la cerámica de disilicato de litio no altera significativamente su rugosidad superficial. Según los valores de resistencia a la flexión biaxial encontrados en el presente estudio se recomienda el uso del ácido fluorhídrico a una concentración 4,6% por 20 segundos tal como lo indica el fabricante.
The purpose of this study was to evaluate in vitro the effect of concentration and time of application of hydrofluoric acid on the surface roughness and fracture resistance of lithium disilicate ceramic generation. 90 IPS e.max press ceramic discs (14 mm diameter, 1.2 mm thick) were fabricated by the press technique and then polished. 60 discs to evaluate the biaxial flexural strength test by the piston and the three spheres were used; under 4.6% hydrofluoric acid and 9.6% conditioned treatment was carried out for 20, 40 and 60 seconds (10 disks per each time and concentration). The remaining 30 discs were used to measure the surface roughness values (Ra) with 4.6% and 9.6% hydrofluoric acid for 20, 40 and 60 seconds (5 discs per group) using 3D optical microscopy, which it possible to measure the values of roughness (Ra). Data were analyzed by ANOVA and Post Hoc to determine significant differences between the study groups. Average values of the biaxial flexural strength in groups 1, 2 and 3 with the application of 4.6% HFL and times of 20, 40 and 60 seconds were 448.45±68.1 MPa, 357.23±59.5 MPa and 317.69±45.97 MPa respectively. The values in groups of 9.6% were 365.40±46.93 MPa, 334.38±40.75 and 348.83±79.39 Mpa. The biaxial flexural strength of the ceramic lithium disilicate generation is affected by the concentration and time of application of hydrofluoric acid. A longer time of application and concentration of hydrofluoric acid, less material strength. The effect of the concentration of hydrofluoric acid and application time on the ceramic lithium disilicate did not significantly alter the roughness of the ceramic surface. According to the values of biaxial flexural strength found in the present study the use of hydrofluoric acid is recommended at a concentration 4.6% for 20 seconds as indicated by the manufacturer.