Properties evaluation of silorane, low-shrinkage, non-flowable and flowable resin-based composites in dentistry

Abstract

Purpose. This study tested the null hypothesis that different classes of direct restorative dental materials: silorane-based resin, low-shrinkage and conventional (non-flowable and flowable) resin-based composite (RBC) do not differ from each other with regard to polymerization shrinkage, depth of cure or microhardness.Methods. 140 RBC samples were fabricated and tested by one calibrated operator. Polymerization shrinkage was measured using a gas pycnometer both before and immediately after curing with 36 J/cm2 light energy density. Depth of cure was determined, using a penetrometer and the Knoop microhardness was tested from the top surface to a depth of 5 mm.Results. Considering polymerization shrinkage, the authors found significant differences (p < 0.05) between different materials: non-flowable RBCs showed lower values compared to flowable RBCs, with the silorane-based resin presenting the smallest shrinkage. The low shrinkage flowable composite performed similarly to non-flowable with significant statistical differences compared to the two other flowable RBCs. Regarding to depth of cure, low-shrinkage flowable RBC, were most effective compared to other groups. Microhardness was generally higher for the non-flowable vs. flowable RBCs (p < 0.05). However, the values for low-shrinkage flowable did not differ significantly from those of non-flowable, but were significantly higher than those of the other flowable RBCs.Clinical Significance. RBCs have undergone many modifications as they have evolved and represent the most relevant restorative materials in today’s dental practice. This study of low-shrinkage RBCs, conventional RBCs (non-flowable and flowable) and silorane-based composite—by in vitro evaluation of volumetric shrinkage, depth of cure and microhardness—reveals that although filler content is an important determinant of polymerization shrinkage, it is not the only variable that affects properties of materials that were tested in this study.

Overviews on the Progress of Flowable Dental Polymeric Composites: Their Composition, Polymerization Process, Flowability and Radiopacity Aspects

“…For instance, compared to the Z350 flowable composite with a filler content of 65 wt%, Z250 conventional composite (both Filtek™ Supreme, 3M ESPE, USA) with a filler content of 82 wt% showed a significantly lower shrinkage strain of 0.70% [ 37 ]. The low shrinkage flowable composite performed similarly to non-flowable composite with a significant difference compared to the other flowable resin-based composites, according to Maia et al [ 16 ].…”

“…Maia et al, in their study concluded that the flowable silorane-based resin exhibited the least polymerization shrinkage among other flowable polymeric composites. Although siloranes are not often on the market in terms of matrix, a low shrinkage flowable composite performed similarly to a non-flowable one [ 16 ]. Among various novel monomers found in commercial products, glycero-phosphate dimethacrylate (GPDM) is also common.…”

Analytical methods for the measurement of polymerization kinetics and stresses of dental resin-based composites: A review

“…They found that Filtek Z250 and Filtek P60 composites showed the least and highest percentage of shrinkage among the tested materials, respectively. In a study conducted by Maia et al .,[ 24 ] the polymerization shrinkage was evaluated by gas pycnometer method. They found that the Silorane-based composites presented the lowest value for shrinkage, followed by the nonflowable resin-based composites (RBCs).…”

Rheological and Mechanical Properties of Resin-Based Materials Applied in Dental Restorations

“…Polymers 2021, 13, x FOR PEER REVIEW 3 of 19 people have been working to optimize their performances, but they still have some defects that cannot be ignored such as polymerization shrinkage and defective physical and mechanical properties [8]. Resin-based composites have undergone many modifications as they evolved and represent the most relevant restorative materials in dental practice today [9]. In this review, the rheological and mechanical properties of resin-based restorative materials with different indications (e.g., dental filling composite, dental adhesive and resin luting cement) are discussed, and the cutting-edge techniques, challenges and future development of resin-based dental restorative materials are also covered.…”