The aim of this study was to evaluate color stability of 3 restorative materials, discoloration ability of different solutions, efficacy of 2 office bleaching agents, and surface roughness and topography. Sixty specimens for Clearfil Majesty Esthetic (CME), Lava Ultimate (LU), and Vita Enamic (VE) were prepared. They were immersed into 3 staining solutions for 2 weeks and then they were bleached. According to the measuredL⁎,a⁎, andb⁎parameters described by CIELAB system, color changes (ΔE00), translucency parameters (TP), whiteness index values (W⁎), and changes in closeness to pure white (ΔW⁎) were calculated. Then 3 specimens from each group were scanned with an atomic force microscope for surface analysis. After staining, CME groups and control groups of LU and VE showed clinically acceptable color changes (ΔE00<1,8). After bleaching, while a reverse effect on color was observed, VE showed the furthest color values to pure white. There was no statistically significant difference between whiteness index values of LU and CME. LU was the most translucent material during the study and TP values of materials showed minimal differences. Most of the VE groups and a control group of LU showed surface roughness (Ra) values higher than critical value for biofilm accumulation (0,2 μm).

The aim of this study was to evaluate the effects of various whitening agents on the surface roughness and optical characteristics of different types of resin composite restorations. Fifty specimens were prepared for each resin [G‐ænial Posterior (GP), SonicFill‐2 (SF), Solidex (SDX), and Nova Compo HF (NC)]. Following baseline color and surface roughness (Ra) measurements, the specimens were randomly divided into 5 groups (n = 10/group) according to whitening concepts: control (distilled water), in‐office bleaching [OB‐(Opalescence Boost)], at‐home bleaching [HB‐(Opalescence PF)], whitening toothpaste [WT‐(Signal White Now)], and whitening mouthwash [WM‐(Listerine Advanced White)]. ∆E₀₀, ∆TP₀₀, and ∆WI_D values were calculated before and after the whitening procedure with a spectrophotometer using the CIEDE2000 formula. Surface roughness measurements were repeated. The surface topography was determined using atomic force microscopy. Two‐ and three‐way analyses of variance and Tukey's post‐hoc test were performed, with p < 0.05 regarded as indicative of significance. No significant differences were detected among the resin composite materials in terms of the ΔE₀₀ values (p > 0.05). Color change of all resin materials was above the AT threshold (>1.8) and the PT threshold (>0.8). All restorative materials presented acceptable (AT<2.62) TP₀₀ values. Solidex specimens demonstrated the lowest W_ID values compared to the other composites. There were significant differences among the whitening procedures with respect to ΔE₀₀, ΔTP₀₀, and W_ID values (p < 0.001). SF/WT combination showed the highest and clinically unacceptable ΔE₀₀ values. The highest roughness values were observed in the SDX specimens and the combination of SDX/OB. The effect of whitening agents on the optical characteristics and surface roughness of restorative materials depends on the type of material, agent, and time.Research Highlights: Clinicians should be aware that long‐term use of over‐the‐counter products due to the abrasive effects of their ingredients and repeated bleaching session applications may affect the color stability and surface roughness of resin composites.

Regeneration is reconstruction of a tissue with the shape and function of the original tissue including vascularization and innervations. Highly degradation of dentin-pulp complex can not be reversed by its own repair mechanisms. For decades, endodontic treatments including pulpectomy and preparation of root canals have been the first choice for these cases. However, root canal treatment method has some unsatisfying consequences like; esthetic problems as a conclusion of discoloration caused by endodontic filling materials, undermined integrity of tooth structure, postoperative fractures, coronal leakage or periapical microleakage, lost sense of environmental changes which can make the recurrent caries or apical infection unnoticeable for patient and shortened lifetime in comparison with vital teeth. Currently regeneration of dentin-pulp complex by tissue engineering approach is thought to be a more appropriate choice instead of root canal treatment according to these outcomes. In this review, we will discuss basic components as stem cells, signaling molecules and scaffolds and also methods used for dentin-pulp tissue engineering.