Light diffusion through composite restorations added with spherical glass mega fillers

Purpose. Evaluate how the spherical glass mega fillers (SGMFs) can positively interfere with light diffusion when incorporated in a composite restoration. Materials and methods. 30 samples (Ss) were performed, applying 2 composite layers of 3 mm each: 6 were made with composite only; 6 with a layer of SGMFs of Ø1.5mm within the first layer of composite; 6 with 2 overlapping layers of SGMFs of Ø1.5mm; 6 with a layer of SGMFs of Ø2mm; 6 with 2 overlapping layers of SGMFs of Ø2mm. The curing time was set at 40s for the first layer, and 120s for the second layer, transilluminated through the first layer. Digital pictures were taken, in standardized settings, during the transillumination, and the light intensity was measured with a digital image analysis software. Results. From a lateral view the Ss with a single layer of SGMFs of Ø1.5mm and Ø2mm, the relative increments of light intensity, were of 24.37% and 33.33% respectively. Concerning the Ss made with 2 layers of SGMFs, the relative increments were of 67.99% and 66.4% respectively. In front view has emerged a relative increase rate of light intensity of 53.66% and 79.58%, in the Ss with a single layer of SGMFs of Ø1.5mm and of Ø2mm respectively. Furthermore, in the Ss with two layers of SGMFs of Ø1.5mm and Ø2mm the relative increments were of 267.53 and 319.63% respectively. Conclusion. The SGMFs are reliable in facilitating light diffusion within the light-curing composite resins.