Analysis of flexural strength of composite resins polymerized by 2nd and 3rd generation leds

Tamires Gonçalves Massotti, Daphne Camara Barcellos, Nicolas Petrucelli, João Paulo Tribst, Sérgio Eduardo de Paiva Gonçalves

Abstract


Objective: This study aimed to investigate the mechanical properties of three composite resins using 2nd and 3rd generation LED-based light-curing devices. Material and Methods: Sixty specimens distributed according to the type of resin(Group Z350 - nanoparticle composite resin [Filtek Z350 / 3M ESPE]; Group AP - microhybrid composite Amelogen Plus/Ultradent; Group DF - Group composite resin Durafil l/Heraeus Kulzer), and the light-curing device(Group 2ndG - 2nd generation LED-based curing unit at power density of 500 mW / cm2; Group 3rdG - 3rd generation LED-based curing unit at power density of 1100 MW/cm2).The specimens were stored in a dark, dry container at 37 °C in an incubator for 24 h and submitted to the mini-flexural test on universal test machine (EMIC) to determine the elastic modulus and flexural strength using a three-point test.The data were submitted to two-way ANOVA (Resin Composite X LED) and Tukey test (5%).Results: Concerning to flexural strength (in MPa), ANOVA showed significant in Tukey test for the interaction between the factors: Group Z350/3rdG - 105.36a; Group AP/3rdG – 81.49ab; Group DF/3rdG – 66.43bc; Group AP/2ndG – 66.13bc; Group DF/2ndG: 60.61bc; Group Z350/2ndG: 47,19c. With regard to the modulus of elasticity (in GPa), the results obtained were: Factor resin composite - Group Z350 (8.85a) > Group AP (7.61b) > Group DF (1.94c); Factor LED - Group 3rdG (7.13a) > Group 2ndG (5.14b). Conclusion:It was concluded that the 3rd generation LED (1100 mw/cm2) significant increased the means of the flexural properties of composites. It was also concluded that the result of flexural properties of compositesdepends on the resin material tested.

 

Keywords: Composite resin; Flexural strength; Modulus of elasticity.


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DOI: https://doi.org/10.14295/bds.2015.v18i1.1073