Accelerated Aging Effects on Color Change, Translucency Parameter, and Surface Hardness of Resin Composites

Abstract

Background. The aging process can induce a change in the surface microstructure of materials, the chemical compositions of matrices, and the filler particles of resin composites. This study is aimed at evaluating the effects of accelerated artificial aging (AAA) on the color change, translucency parameter (TP), and surface hardness of resin composites. Methods. Five resin composite materials (Tetric N-Ceram, Filtek Z250, Charisma Smart, Herculite Classic, and Escom100) were evaluated. A spectrophotometer was used for color measurements ( L ∗ , a ∗ , and b ∗ ). TP and color changes ( Δ E 00 ) were calculated using the CIEDE2000 formula. The resin materials were subjected to aging for 300 hours. The hardness and TP values were measured before and after AAA. One- and two-way ANOVA and the Tukey test were used. The significance level was accepted as p < 0.05 . Results. Escom100 had significantly higher Δ E 00 values than the other resin composites, and Charisma Smart had significantly lower Δ E 00 values than the other tested materials ( p < 0.05 ). Before and after AAA, Charisma Smart had the lowest TP values, and Filtek Z250 exhibited the highest hardness values ( p < 0.05 ). For TP and surface hardness, the effect size value of the composite material was found to be higher than that of AAA. Conclusions. After AAA, the investigated resin composites had Δ E 00 values that were above clinically acceptable thresholds. After aging, the tested materials generally exhibited decreases in L ∗ values and a ∗ values, while increases in b ∗ values were observed. The ΔTP values of the resin composites were similar. AAA significantly increased the surface hardness of the tested materials.

Effect of Polishing Systems on Translucency Parameter of the Resin Composites after Aging

“…The optical characteristics of teeth depend on the region, between the teeth, and factors, such as the choice of material. Ideally, the color and translucency of restorative materials should mimic natural teeth in esthetic restorations [8]. The ability of a material to allow passage of light is an indicator of translucency, and higher TP values show higher translucency [2].…”

“…Material composition differences can be attributed to variations in TP values. Reports show that the translucency values of the materials are affected by many factors, [4] such as the composition of the applied resin matrix, [4] resin matrix content, [20] distribution of filler, [21] number of particles per volume, different chemical structures, added substances, [8] and types of polymerization initiator/inhibitor [21]. In resin composites, light absorption is enabled by the organic matrix, while diffusion is due to the size and distribution of inorganic fillers and the difference between the refractive index of the organic matrix and inorganic filler contens [14,22].…”

“…After measurements, all specimens were aged for 300 h and 150 kJ/m 2 in an accelerated aging chamber (Atlas ci 4000; Atlas Electronic Devices Co., Mount Prospect, Il, USA) The aging procedure was performed as stated in the previous study [8]. The aging process was as follows: 60 min in the dark with back water spray; 40 min under illumination; 20 min under illumination water spray; and 60 min under illumination.…”

“…However, studies involving composites subjected to accelerated artificial aging (AAA) are difficult to compare due to differences in used methods. AAA imitates the effect of prolonged exposure to environmental conditions through an accelerated weathering process that includes differences in light, temperature, and humidity and ensures that AAA in short time intervals is equivalent to long-term use under normal conditions [8].…”

Effect of aging and fiber‐reinforcement on color stability, translucency, and microhardness of single‐shade resin composites versus multi‐shade resin composite

“…4 Restorative materials must reproduce both the color and translucency of natural teeth to make a restoration imperceptible, and they should have long-term color stability. 17 Translucency is a significant optical property of resin composites, and it is determined by the color difference of a material with uniform thickness on a white and black background, commonly referred to as the translucency parameter (TP) in dentistry. 17,18 Translucency is characterized by the color difference exhibited by a material that is uniformly optically distributed throughout its thickness and is in optical contact with an ideal white background (Rg = 1) and an ideal black background (Rg = 0).…”