Purpose: This study investigated discoloration and surface roughness (Ra) of resin-based computer aided design (CAD)/computer manufacturing (CAM) blocks direct indirect resin composites after staining with coffee. Materials & Methods: Using a Teflon mold, 60 disc shaped specimens (8×2 mm2) were fabricated from (Estelite Asteria GrandioSO) (Gradia Plus) composites, 30 CAD/CAM (12×14×2 mm3) p...

OBJECTIVE Tooth fracture is a common dental problem. By extension of cavity dimensions, the remaining tooth structure weakens and occlusal forces may cause tooth fracture. The aim of this study was to evaluate and compare the fracture resistance of teeth restored with direct and indirect composite restorations. MATERIALS AND METHODS Sixty-five sound maxillary premolar teeth were chosen and ra...

Objectives: The aim of this study was to evaluate the effect of six herbal teas on the color stability of two types of nanohybrid and one microhybrid resin composite.  Materials and Methods: 70 disc-shaped specimens, 210 in total (7*2mm), were fabricated from each of the following materials in metal mould : Tetric N ceram, Grandio, Gradia Direct Anterior. Specimens were stored in distilled wate...

PURPOSE To determine changes in surface gloss of different composite materials after laboratory toothbrushing simulation. METHODS 40 specimens were fabricated for each material (Filtek Supreme XTE, Renamel, Empress Direct, Gradia Direct, Edelweiss, G-aenial, Venus Pearl and Venus Diamond) and polished with 120-, 220-, 500-, 1200-, 2400- and 4000- grit SiC abrasive paper, respectively. Gloss m...

The purpose of this study was to evaluate the influence of air-abrasion and subsequent heat treatment on the shear bond strength of the bond between indirect composites and a zirconia material. Four surface preparations were employed; ground flat, then heated to regenerate the crystal phase (C); air-abraded with alumina for 10 s (S10), for 20 s (S20), and air-abraded for 10 s and heated (H). Di...

OBJECTIVE Color match between fiber-reinforced composite (FRC) restorations and teeth is an imperative factor in esthetic dentistry. The purpose of this study is to evaluate the influence of veneering composites and fibers on the color change of FRC restorations. MATERIALS AND METHODS Glass and polyethylene fibers were used to reinforce a direct microhybrid composite (Z250, 3M ESPE) and a mic...

The contraction stress generated during the photopolymerization of resin dental composites is the major disadvantage. The water sorption in the oral environment should counteract the contraction stress. The purpose was to evaluate the influence of the water sorption of composite materials on polymerization shrinkage stress generated at the restoration-tooth interface. The following materials we...