In Vitro Evaluation of Translucency and Color Stability of CAD/CAM Polymer‐Infiltrated Ceramic Materials after Accelerated Aging

Abstract

Purpose To investigate and compare the translucency and color stability of a newly introduced polymer‐infiltrated ceramic network (PICN) material (Crystal Ultra) to those of clinically well‐established restorative materials. Materials and Methods A total of 80 specimens measuring (12 × 14 × 1 mm ± 0.05 mm) were prepared from five CAD/CAM (IPS e.max (IPS), Lava Ultimate (LU), Cerasmart (CS), Vita Enamic (VE), Crystal Ultra (CU)) high translucency (HT) blocks in A2 or equivalent shades. Specimens were randomly allocated into two groups (A and B) (n = 8), and were subjected to 5,000 thermal‐cycles (TC). This was followed by one‐week immersion of group A specimens in coffee (staining) solution and group B specimens in distilled water. Following immersion, the specimens from both groups were further subjected to 5,000 TC. A spectrophotometer was used to measure the translucency parameter (TP) and color change (ΔE00) of the samples using CIELAB color coordinates at baseline, after 5,000 TC, following immersion, and after further 5,000 TC. Color stability was evaluated using the CIEDE2000 formula. Data were analyzed by non‐parametric tests (α = 0.05). Results The TP values of the CAD/CAM materials ranged from 18.0‐22.0. Following the initial TC, the changes in TP values were significant for VE (p = 0.012). Coffee immersion and further TC significantly impacted the TP values of PICN (VE and CU) materials compared to glass‐ ceramics (IPS), and resin nanoceramic (CS and LU) materials (p = 0.012). The comparison between CAD/CAM materials at different intervals showed a significant difference in the TP values (p < 0.01). The materials showed perceptible color changes following the initial TC except for PICN materials which demonstrated acceptable color changes. The major color difference was noticed for the resin nanoceramic specimens immersed in coffee; LU and CS showed higher color changes (ΔE00 = 2.45 and 2.09, respectively) than VE and CU (ΔE00 < 1.8). Conclusions The translucency of the newly introduced Crystal Ultra PICN material was low compared to the resin nanoceramics and lithium disilicate glass‐ceramic. The Crystal Ultra material exhibited better color stability compared to resin nanoceramics, but higher color change when compared with Vita Enamic PICN and lithium disilicate glass‐ceramic CAD/CAM materials.

Repair Bond Strength of Composite Resin to Aged Resin and Glass-Matrix CAD/CAM Ceramic Materials Using Two Different Repair Systems

“…Resin-matrix ceramic materials were developed to combine the advantageous properties of composite resin and ceramic materials. Accordingly, the strength, color stability, and durability of ceramics were combined with ease of machinability, low abrasiveness, polishability, and intra-oral repairability properties of composite resin [2]. Another advantage of these materials is the low modulus of elasticity compared to pure ceramic materials, providing good resilience, thereby improving the resistance to damaging occlusal forces.…”

“…Crystal Ultra (CU; Digital Dental) is a new resin-matrix ceramic material with a high polymer/ceramic ratio and comprises 70% ceramic-like inorganic silicate glass fillers with 30% cross-linked polymers [2,22,23]. The material's composition differs significantly from that of well-known resin-matrix ceramics.…”

Color stability of 3D-printed denture resins: effect of aging, mechanical brushing and immersion in staining medium

“…The coffee constituents (tannin and chlorogenic acids) and pH (4.9 to 5.2) are found to induce and accelerate the discoloration process. 28 However, the assumption was wrong as coffee's discoloration potential was below lemon juice and coke. The low discoloration of specimens in coffee solution is possibly explained by the dislodging of the coffee layers from the specimen surface into the solution as they reach a certain thickness.…”

“…Once the prepared solution was cooled down to room temperature, it was filtered using a filter paper to remove the residue. 28 The AS was prepared by a pharmacist per the description from a previous study. 29 The pH of beverages and AS was determined using a benchtop pH meter (pH 2700, OAKTON Instruments, Vernon Hills, IL, USA).…”

Stain Susceptibility of 3D-Printed Nanohybrid Composite Restorative Material and the Efficacy of Different Stain Removal Techniques: An In Vitro Study

“…Tannin and chlorogenic acid in coffee have been shown to diffuse within the structure of the immersed material and consequently cause its discoloration. Further, the pH of coffee ranges from 4.9 to 5.2, a range of values which has been reported to accelerate the staining capacity of material [ 12 , 27 , 28 ] ( Table 1 , Figure 2 ). In this experiment, all tested materials were immersed in coffee and tea, and showed ΔE 00 values higher than the acceptability threshold, which is reported to be ΔE 00 ≤ 1.8 in the literature [ 20 ].…”