Polymerization Behavior and Mechanical Properties of High-Viscosity Bulk Fill and Low Shrinkage Resin Composites

Abstract

The present study determined the mechanical properties and volumetric polymerization shrinkage of different categories of resin composite. Three high viscosity bulk fill resin composites were tested: Tetric EvoCeram Bulk Fill (TB, Ivoclar Vivadent), Filtek Bulk Fill posterior restorative (FB, 3M ESPE), and Sonic Fill (SF, Kerr Corp). Two low-shrinkage resin composites, Kalore (KL, GC Corp) and Filtek LS Posterior (LS, 3M ESPE), were used. Three conventional resin composites, Herculite Ultra (HU, Kerr Corp), Estelite ∑ Quick (EQ, Tokuyama Dental), and Filtek Supreme Ultra (SU, 3M ESPE), were used as comparison materials. Following ISO Specification 4049, six specimens for each resin composite were used to determine flexural strength, elastic modulus, and resilience. Volumetric polymerization shrinkage was determined using a water-filled dilatometer. Data were evaluated using analysis of variance followed by Tukey's honestly significant difference test (α=0.05). The flexural strength of the resin composites ranged from 115.4 to 148.1 MPa, the elastic modulus ranged from 5.6 to 13.4 GPa, and the resilience ranged from 0.70 to 1.0 MJ/m. There were significant differences in flexural properties between the materials but no clear outliers. Volumetric changes as a function of time over a duration of 180 seconds depended on the type of resin composite. However, for all the resin composites, apart from LS, volumetric shrinkage began soon after the start of light irradiation, and a rapid decrease in volume during light irradiation followed by a slower decrease was observed. The low shrinkage resin composites KL and LS showed significantly lower volumetric shrinkage than the other tested materials at the measuring point of 180 seconds. In contrast, the three bulk fill resin composites showed higher volumetric change than the other resin composites. The findings from this study provide clinicians with valuable information regarding the mechanical properties and polymerization kinetics of these categories of current resin composite.

Effect of different clinical applications on physico-mechanical properties of composite resins

“…FS has been assessed in several previous studies as a clinically relevant property for restorative materials meant to be used in areas that are exposed to force (SHIBASAKI et al, 2017, FINAN et al, 2013, YAMASAKI et al, 2013, GORACCI et al, 2014. The highest FS values measured in our study were for the resin composite SonicFill.…”

Two Years Clinical Evaluation of a Bulk Fill Composite Resin Compared With a Nanohybride Incremental Fill Composite Resin in Class Ιι Cavities

“…Restoration placement techniques are broadly documented as a main issue in the reduction of the shrinkage stresses [8,10] . Incremental filling techniques of composite resin are generally favoured to obtain effective marginal seal and decrease the clinical consequences of polymerization shrinkage and stress [23] . Incremental techniques have been suggested to compensate for the polymerization shrinkage of composites.…”

Restauração de dentes tratados endodonticamente com resinas bulk-fill: revisão integrativa

“…Possivelmente a elevada translucidez, associada ao sistema de polimerização otimizado, fez com que, mesmo a resina sendo aplicada em grandes volumes, a polimerização fosse adequada, conferindo propriedades mecânicas satisfatórias. 5,25 Além disso, embora haja tensões de contração distintas entre os tipos de resina e técnicas de inserção, 17 essa variável não afetou a resistência à fratura dos dentes restaurados. [20][21][22][23][24] A avaliação da adaptação das restaurações ao assoalho da câmara pulpar utilizando resinas bulk--fill flow não difere de uma resina convencional flow e é melhor que uma resina convencional.…”