scholarly journals Characterization of Bis-Acryl Composite Resins for Provisional Restorations

2017 ◽  
Vol 28 (3) ◽  
pp. 354-361 ◽  
Author(s):  
Júlia K. Schwantz ◽  
Aline Oliveira-Ogliari ◽  
Carine T. Meereis ◽  
Fernanda B. Leal ◽  
Fabrício A. Ogliari ◽  
...  

Abstract This study investigated the in vitro performance of the commercial bis-acryl composite resins Systemp C&B II (SYS, Ivoclar Vivadent), Protemp 4 (PT4, 3M ESPE), Structur 2C (ST2, Voco) and ProviPlast (PVP, Biodinamica). Characterization involved optical (color stability, translucency parameter, fluorescence), surface (roughness, morphology and elemental composition), physical-chemical (viscosity, polymerization kinetics) and mechanical analyses (Poisson ratio, biaxial flexural strength, flexural modulus). Most tests were carried out after 24 h, but optical and mechanical analyses were carried out after storage in water at 37 °C for 1, 15, and 30 days. Data were statistically analyzed (a=0.05). Most results were material dependent. SYS and PT4 showed stability in color and translucency over time. All materials had similar or higher fluorescence than human enamel. SC2 and PVP showed rougher surfaces than the other bis-acryl composites. Smaller filler particles were observed on the surface of PT4 and PVP compared with the coarser particles from ST2 and SYS. Viscosity readings indicated a thixotropic behavior for all tested materials. SYS had the lowest and PT4 the highest degree of C=C conversion after 10 min. In the polymerization kinetics, PT4 had the highest maximum polymerization rate and reached earlier the transition between polymerization autoacceleration and autodeceleration. PT4 and SYS had significantly higher flexural strength and modulus than ST2 and PVP for most storage times. Results for Poisson ratio varied between materials. Longer storage periods were generally associated with higher frequency of catastrophic failures in the flexural tests. In conclusion, the performance of bis-acryl composite resins varied largely among materials.

2013 ◽  
Vol 24 (3) ◽  
pp. 279-283 ◽  
Author(s):  
Ana Caroline Silva Gama ◽  
Andre Guaraci de Vito Moraes ◽  
Lilyan Cardoso Yamasaki ◽  
Alessandro Dourado Loguercio ◽  
Ceci Nunes Carvalho ◽  
...  

The purpose of this study was to evaluate in vitro the shear bond strength to enamel, flexural strength, flexural modulus, and contraction stress of one orthodontic composite and two flowable composites. Orthodontic brackets were bonded to 45 human maxillary premolars with the composites Transbond XT, Filtek Z-350 flow and Opallis flow and tested for shear bond strength. For measurement of flexural strength and flexural modulus, specimens were fabricated and tested under flexion. For the contraction stress test, cylindrical specimens were tested and an extensometer determined the height of the specimens. The data were subjected to one-way ANOVA and Tukey's test (α=0.05). The shear bond strength values were significantly lower (p<0.05) for the flowable composites compared with the orthodontic composite. For the flexural strength, no statistically significant difference was found among the composites (p>0.05) while the flexural modulus was significantly higher (p<0.05) for Transbond XT than for Filtek Z-350 flow and Opallis flow. The orthodontic composite presented significantly lower contraction stress values than the flowable composites (p<0.05). The light-activated orthodontic composite material presented higher flexural modulus and shear bond strength and lower contraction stress than both flowable composites.


Author(s):  
Daniele Esteves Pepelascov ◽  
Lidiane Vizioli de Castro-Hoshino ◽  
Leandro Herculano da Silva ◽  
Ronaldo Hirata ◽  
Francielle Sato ◽  
...  

2010 ◽  
Vol 123-125 ◽  
pp. 3-6
Author(s):  
Harry Ku ◽  
Mohan Trada ◽  
Rezwanul Huq

Vinyl ester resin was filled with of glass powder with a view to increasing the flexural strength of the composites for civil and structural applications by a research Centre on composites, University of Southern Queensland (USQ). In order to reduce costs, the Centre wishes to fill as much glass powder as possible to the resin subject to maintaining sufficient strength of the composites in civil and structural applications. This project varies the percentage by weight of the glass powder in the composites, which are then subjected to flexural tests. The flexural strength and strain of the glass powder filled vinyl ester composites decreased with increasing filler content but the flexural modulus was highest at 20 w/t % of glass powder. Scanning Electron Microscope (SEM) was used to analyze the fractured samples and it was found that the fractured surfaces examined were correlated with the flexural properties.


2007 ◽  
Vol 18 (2) ◽  
pp. 119-123 ◽  
Author(s):  
Fernanda de Carvalho Panzeri Pires-de-Souza ◽  
Lucas da Fonseca Roberti Garcia ◽  
Hisham Mohamad Hamida ◽  
Luciana Assirati Casemiro

The purpose of this study was to evaluate, in vitro, the color stability of three composite resins of two different shades (A3 and C3) cured with either a quartz tungsten halogen (QTH) or a light emitting diode (LED) source. Forty specimens (20 x 2 mm) were prepared for each composite (Tetric Ceram®, Heliomolar® and Esthet-X®), being 20 for each shade. In each group, 10 specimens were light-cured using the QTH unit and 10 with the LED source. The shade of the materials was evaluated before and after submitting the specimens to artificial accelerated aging (4 h UV-B/4 h condensing vapor), using a reflection spectrophotometer. deltaE means were calculated and analyzed statistically by 2-way ANOVA and Tukey's test at 5% significance level. Both A3 and C3 shades of Esthet-X composite resin showed the lowest color change when cured with the QTH light, while Tetric C3 cured with the QTH light showed the highest color change.


2017 ◽  
Vol 6 (3) ◽  
pp. 2619-2625
Author(s):  
Deepika Thosre Chandhok ◽  
◽  
Jasmeet Singh Chandhok ◽  
Sanjyot Mulay ◽  
Grishmi Niswade ◽  
...  

2020 ◽  
Vol 9 (12) ◽  
pp. e32091211128
Author(s):  
Nathalie Murielly Rolim de Abreu ◽  
Ruth Venâncio Fernandes Dantas ◽  
Hugo Ramalho Sarmento ◽  
Robinsom Viégas Montenegro ◽  
Heloísa Helena Pinho Veloso ◽  
...  

Objective: To evaluate the influence of alternative photoinitiators present in composite resins related to yellowing, color stability, photosensitivity, light-curing efficiency, degree of conversion, and microhardness. Materials and methods: The literature was reviewed by two independent reviewers at PubMed. The search strategy was carried out using the following descriptors: (Photoinitiators, dental) AND (Curing lights, dental) AND (Composite Resins) NOT (Case report). The electronic search was carried out until March 2019, without language restrictions, and inclusion and exclusion criteria were applied in the selection. Results: Thirteen articles met the previously established criteria, and all were included. Of these, most were in vitro studies. After the aging of the composite, all systems suffered yellowing, however the isolates with camphorquinone were the most affected and, although there is a greater tendency to yellowing, this does not directly affect color stability. However, the literature is still conflicting about which system has significant color stability. Regarding photosensitivity, all photoinitiators have different absorption peaks. In this sense, the photopolymerization must be chosen with caution, as the conversion of monomers and microhardness proved to be directly linked to the correct combination of photoactivator and photopolymerizing unit. Conclusion: Alternative photoinitiators have a lower yellowing rate and good color stability. They can be up to five times more sensitive than systems containing isolated camphorquinone. Only third-generation light-emitting diodes photopolymerize satisfactorily composite resins that have alternative photoinitiators in their composition, ensuring a good degree of conversion and acceptable Knoop microhardness values.


2020 ◽  
Vol 24 (1) ◽  
Author(s):  
Beatriz Maria Arruda ◽  
Julio Cesar Bassi ◽  
Rafael Pino Vitti ◽  
Renata Siqueira Scatolin

 Objective: The aim of this in vitro study was to evaluate the color stability of different bulk fill composite resins after extrinsic staining with coffee. Material and methods: Forty-eight disk-shaped specimens (6 mm diameter x 2 mm thick) of each composite resin were prepared for color change test. The composite resins were divided into 4 groups (n=12): one conventional composite resin (Filtek Z250) and three bulk-fill composite resins (Filtek Bulk Fill, Aura Bulk Fill, and Opus Bulk Fill). The samples were stained with 20 mL coffee solution for 7 days, with the solution being replaced every 24 h. The color change analysis was performed using a spectrophotometer, according to the CIE Lab formula. Data were analyzed using the Analysis of variance (ANOVA) and Tukey HSD tests (?=0.05). Results: The results revealed significant differences in color change among the composite resins tested (?<0.0001). The Aura Bulk Fill and Opus Bulk Fill showed the highest color change values. Conclusions: Thus, all the resins analyzed were susceptible to extrinsic staining with coffee, and the Filtek Bulk Fill showed the lowest color change value.


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