Full in-vitro analyses of new-generation bulk fill dental composites cured by halogen light

Polymerization shrinkage, microhardness and depth of cure of bulk fill resin composites

“…The results for Z3XT and TBF are similar to the ones reported by Rodriguez et al 30) . As expected, microhardness' results for lower viscosity resin composites were lower when compared with high viscosity resin composites 22,31) , with Z3F (33.31±3.15) and XB (31.95±2.66) showing the highest values, followed by SDR (22.05±2.07) and FBF (16.21±2.28). Despite presenting similar filler content as FBF and SDR 32) , Z3F (65%) 33) showed similar microhardness values as XB, which presents a higher filler content (75%) 26,32) .…”

“…An increase in microhardness values is expected as the filler content increases 22,30,31,35,37) . In the present study, considering the filler content reported by the manufacturers, it was possible to observe a tendency of moderate correlation between microhardness and filler content, showing an increase in the microhardness as the amount of filler increases, especially when comparing low and high viscosity resin composites (R 2 =0.5708, Fig.…”

“…The high viscosity resin composites showed very heterogeneous results, but definitely higher than the low viscosity resin composites, which might need a capping layer. The heterogeneous values observed for high viscosity resin composites can rely partially on the lower elastic modulus observed for some of the bulk fill resin composites, associated with the different filler contents and organic matrix composition 31,[34][35][36] . Thus, it might be important to consider each resin composite according with each clinical indication.…”

Degree of Conversion of Bulk Fill Composites at Different Depths

“…In addition to load quantity, changes in monomer structure and in polymerization reaction dynamics are the most promising approaches. 2,3 Composites mainly consist of mineral loads dispersed in an organic resin matrix and an initiator system. 4 The resin matrix consists of a multifunctional long-chain monomer which, when polymerized, results in a threedimensional network of crossed bonds known as polymers.…”

“…18 Many different materials have been released in recent years to reduce the clinical time required to perform direct adhesive restorations of posterior teeth. 3,19 According to their manufacturers, these materials share the property of allowing light to pass through even when greater thicknesses are used (4-5 mm) without negatively affecting polymerization shrinkage, adaptation to the cavity walls, or the DC. It is clear that, in addition to the DC of a given material, its depth of cure must also be determined.…”