The Effect of a Modeling Resin and Thermocycling on the Surface Hardness, Roughness, and Color of Different Resin Composites

Abstract

The effect of modeling resin on surface microhardness, roughness, and color stability of composite materials depends on the type of resin composite. In clinical practice, the adverse effects of modeling resin might be alleviated by a proper finishing and polishing procedure.

Effects of modeling liquid/resin and polishing on the color change of resin composite

“…However, doubts have arisen regarding possible changes in the characteristics and properties of composites caused by the application of modeling liquids, particularly those related to the color stability of the restoration over time. 9 Thus, the present study evaluated the effects of the presence of modeling liquid and polishing state on the color change of RC exposed to red wine staining over time. On analysis of the presence of modeling liquid, the specimens prepared with modeling liquid exhibited reduced overall color change, compared with the specimens prepared without modeling liquid, thus rejecting the first hypothesis of the study.…”

“…8 Although the use of modeling liquids may enhance the handling application of composites, there are few reports in the literature to support this technique. Moreover, and according to Tuncer et al,9 who investigated the hardness, roughness, and color stability of composite specimens that received a superficial layer of resin adhesive as a modeling resin, the modeling resin may negatively affect some of these properties, although this was dependent on the type of composite tested.…”

“…9 Taking these factors into consideration, the present study evaluated the effects of the presence of a modeling liquid (adhesive resin) between layers of RC and the finishing/polishing state of the material on the change in the color of specimens exposed to red wine staining over time. The hypotheses were (1) the presence of a modeling liquid within the composite structure would increase the color change over time and (2) the smoother the surface of the material, the lower the change in color.…”

Effects of adhesive used as modeling liquid on the stability of the color and opacity of composites

“…However, obtaining satisfactory esthetic restorations depends on both clinicians’ skill and the physical properties of the composite, including its handling characteristics. As the stickiness of several composites can hinder the insertion and sculpting procedures, some clinicians have used low viscosity materials as modeler liquids to facilitate the building up of the restoration by reducing the surface tension of the composite . Moreover, the low viscosity resin might penetrate through any porosity created during the incremental insertion of the composite, helping to reduce the defects on the restoration's body and ultimately improving the mechanical properties and color stability …”

The effect of surface sealant application and accelerated aging on posterior restorative surfaces: An SEM and AFM study

“…Another crucial factor affecting the longterm performance of resin-based restorations is polymer degradation 8) , which may result from deterioration of the organic matrix, filler rupture, filler-particle fracture, or propagation of micro-cracks in the material 4) due to mechanical and environmental loading and humidity. Surface degradation and deterioration of composites can be accelerated by thermo/mechanical stresses and chemical changes in the oral environment [9][10][11] . In vitro studies typically use thermocycling to examine the aging behavior of different dental materials, and artificial aging has generally been shown to accelerate the degradation of organic and inorganic matrices 12,13) to the significant detriment of the mechanical performance of the material.…”