Biomechanical properties of 3D-printed resin composites compared with subtractive CAD/CAM materials and direct light-cured composites: Color stability.

In vitro two-body wear of inlay-onlay composite resin restoratives

The objective of this study was to evaluate whether any coating material would have a beneficial influence on maintaining color stability and surface roughness and to what extent an uncoated resin composite can keep its original color. The study evaluated three direct composite resins (Gradia Direct Anterior A2, Tetric EvoCeram A2, Filtek Z550 A2) using 30 samples per material (1 mm thick, 14 × 10 × 1 mm). Samples were prepared in 3D-printed molds, light-cured for 40 s, and initially smoothed with abrasive paper (grit 400–2000). The surface treatments applied were as follows: group 1—polished with a brush and Compo + polishing paste, group 2—conditioned with 37% phosphoric acid, ScotchBond adhesive applied, light-cured. All samples were cleaned ultrasonically for 5 min. Initial surface roughness and color were measured with a profilometer and spectrophotometer. Samples were then immersed in distilled water (control at 37 °C), Coca-Cola and red wine (at 10 °C) with surface roughness and color changes measurements taken on days 1, 7, 14 and 90. Immersion media were refreshed weekly. The most notable color changes after immersion in coloring solutions were observed in the groups treated with Coca-Cola and red wine compared with the control group in distilled water. Tetric EvoCeram sealed and Gradia sealed maintained the greatest resistance to perceptible coloration over 90 days, while Filtek Z550 performed the poorest. Tetric EvoCeram sealed maintained the greatest color stability (ΔE < 3.5 at 90 days), whereas Filtek Z550 sealed showed early degradation. Roughness is often decreased by surface sealing. As immersion time rises, unsealed surfaces often become noticeably rougher than sealed ones. This study simulates the oral environment and the exposure of restorative materials to staining agents. As the loss of esthetic properties over time is a continuous problem, the clinical significance of this research lies in demonstrating how a restorative material could resist pigmentation, when in contact with well-known high staining beverages, in order to maintain its esthetic properties and remain suitable for long-term use in the oral cavity. Moreover, the hypothesis that a coating material would protect the resin composite surface and reduce discoloration and surface roughness was tested.

To evaluate the efficacy of in-office bleaching on stain removal from stained resin composite and ceramic computer-assisted design/computer-assisted manufacturing (CAD/CAM) blocks and direct resin composites. Forty disk-shaped samples were fabricated from each of nine materials: six CAD/CAM (VITABLOCS Mark II, Paradigm MZ100, Exp Vita Hybrid Ceramic, VITA ENAMIC, Exp Kerr, and LAVA Ultimate) and three direct resin composites (Filtek Supreme, Venus Diamond, and Filtek Silorane). Samples were randomly divided into five groups (n = 8), each stained with a particular staining solution. Using a calibrated spectrophotometer and a black background, L*a*b* values were assessed before and after 120 days of staining. Samples were subjected to in-office bleaching using 40% hydrogen peroxide gel for one hour. At subsequent assessment, color change (ΔE) was calculated as the difference between L*a*b* values. Both ANOVA and the Duncan test were used to identify differences between groups (α = 0.05). Bleaching resulted in significant differences in ΔE values for all materials (P < .001). Bleaching efficacy was highly influenced by material composition and staining solution. Residual color values after bleaching for ceramic and hybrid ceramics ranged from -0.49 to 2.35, within the clinically acceptable maximum of 3.3. Values after bleaching for resin-based CAD/CAM ranged from -0.7 to 7.08 while direct resin composites values ranged from -1.47 to 25.13. Coffee left the greatest residual color on all materials. Based on material nature, 40% hydrogen peroxide bleaching can remove staining. The new resin-based CAD/CAM blocks showed promising results in terms of color stability. Bleaching using 40% hydrogen peroxide can be an effective method to remove stains from dental restorations. In this way, restoration replacement as a result of discoloration may no longer be necessary.

The effect of artificial aging on Martens hardness and indentation modulus of different dental CAD/CAM restorative materials.

Translucency of esthetic dental restorative CAD/CAM materials and composite resins with respect to thickness and surface roughness

IntroductionThis study aims to determine the color stability of direct and indirect restorative materials after immersion in coffee solution.Materials and MethodsA total of 32 blocks (12 mm × 10 mm × 2 mm) were prepared from four tested materials; feldspar ceramic (VITABLOCS Mark II: Vita Zahnfabrik, Germany), hybrid ceramic (Vita Enamic: Vita Zahnfabrik, Germany), indirect composite resin (Gradia Indirect: GC, Japan), and direct composite resin (G-aenial anterior: GC, Japan). The color of all specimens was measured by a spectroradiometer using CIELAB color space before and after thermocycling (5000 cycles) followed by immersion in coffee solution. The color difference (ΔE) was calculated by measuring L∗, a∗, and b∗ color values. Data were analyzed using ANOVA and post hoc tests at the significant level of 0.05.ResultsAll materials tested exhibited unacceptable color changes after immersion in the coffee solution. The highest value of color change (ΔE) was reported for the Gradia Indirect composite, followed by the Vita Enamic and G-aenial and VITABLOCS Mark II groups, respectively. However, no significant differences were observed between any of the groups (p = 0.058). G-aenial showed the most visual discoloration.ConclusionsThe study demonstrated that there were no statistically significant differences in color change between the various groups following immersion in coffee. Additionally, the color change exceeded the clinically acceptable limit in all samples. It is noteworthy that differences in the initial color values (L∗, a∗, and b∗) resulting from the different compositions and structures of the materials may influence visual perception.

This study investigates the influence of water immersion on direct composite resins in comparison with subtractive processed composite resins. It evaluates changes in their optical characteristics, surface roughness, solubility, and water sorption. Four CAD/CAM materials (Vita Enamic, Brilliant, Cerasmart, and Tetric) and three direct composite resins (Gradia Direct Anterior A2, Tetric Evo Ceram A2, and Filtek Z550 A2) were examined. Direct composite samples were created using a 3D-printed mold, compressed, and photopolymerized, whereas CAD/CAM samples were sectioned and processed to the same dimensions. Seventy samples (n = 10) were prepared. After dehydration and initial weighing, samples were immersed in distilled water for 30 days, with mass changes recorded at multiple time points. Surface roughness and optical parameters were measured at three stages: post-dehydration, post-immersion, and post-reconditioning. ANOVA, unpaired and paired Student's t-tests, and Pearson correlation coefficient were used to evaluate the variables. The drawn conclusion was that there were significant differences both between stages and between the materials. The most stable material in terms of water sorption was Vita Enamic. Regarding the optical parameters, Brilliant, Vita, and Cerasmart displayed higher stability, while Tetric CAD, Tetric, Gradia, and Filtek showed increased sensitivity to water immersion and re-desiccation. Gradia exhibited the highest surface roughness, while the CAD-CAM materials demonstrated the greatest stability.

Aim: To evaluate the effect of background color on the color change evaluation of composite resins of different translucency. Material and Method: In our study, Estelite ∑ Quick (EQ) CE, OA2 and Filtek Ultimate (FU) A2 Enamel, A2 Dentin composites were used. Disc-shaped samples were prepared from the composites of both brands by layering enamel and dentin alone and enamel + dentin (n=10). After preparation, samples were kept in distilled water for 24 hours and then in coloring solution (NescafeClassic) for 10 days. Colors of the composite samples were measured with a spectrophotometer (VıtaEasyshade) on black, white and gray backgrounds after 24 hours (initial) and after coloring. Color change value (ΔE00) was calculated using two measurement values for each background. Color change values of the same composites measured on different backgrounds were compared. Additionally, the ΔE00 values of different translucent tones from the same company were compared on different backgrounds. One-way ANOVA and Tukey's post-hoc tests were used for statistical analysis. (α=0.05). Results: When used layered with dentin, enamel composites consistently showed lower ΔE00 values than enamel composites alone (p&lt;0.05). When comparing ΔE00 values of the same composite resin samples on different background colors, the ΔE00 values measured on black background were found to be higher only for FU enamel compared to the values measured on the other two backgrounds (p&lt;0.05). When different translucent shades from the same company were compared on different backgrounds, the ΔE00 ranking was found to be enamel &gt; dentin &gt;/=mine + dentin for all backgrounds. Conclusion: Different backgrounds did not affect the color evaluation of samples containing an opaque composite resin, dentin composite; however, they did affect the color evaluation of FU enamel, which is a translucent composite resin. When translucent composite resins are layered with more opaque composite resins, more accurate color evaluation can be achieved.

The aim of this study was to evaluate the staining susceptibility of a silorane (Filtek Silorane), an ormocer (Ceram X Duo), a methacrylate (Tetric EvoCeram) and a compomer (Dyract) exposed on the long term to various staining agents by using ΔE and ΔE 00 colour-difference formulas. Thirty-six disc-shaped specimens were made of each of the four chemically different materials, randomly divided in six groups (n=6) and immersed in five staining solutions (red wine, juice, coke, tea and coffee) or stored dry (control) in an incubator at 37°C for 99days. Spectrophotometric measurements by means of a spectrophotometer (Spectroshade Handy Dental, MHT) were repeated over a white (L*=92.6, a*=-1.2, b*=2.9) and black (L*=1.6, a*=1.2, b*=-1.0) background made of plasticized paper, in order to determine the colour changes according to ΔE, ΔE 00 and translucency formulas. Statistical analysis was performed by means of factorial Anova, Fisher's LSD test (post hoc) and a Spearman rank correlation between ΔE and ΔE 00. When analysed over a white background, mean ΔE 00 values were highly significantly different and varied from 0.8 (Ceram X Duo/air) to 20.9 (Ceram X Duo/red wine). When analysed over a black background, mean ΔE 00 values were highly significantly different and varied from 1.0 (Ceram X Duo and Tetric/air) to 25.2 (Ceram X Duo/red wine). Differences in translucency varied from 0.3 (Ceram X Duo/air) to 21.1 (Ceram X Duo/juice). The correlation between ΔE and ΔE 00 over a white background was 0.9928, while over a black background, it was 0.9886.

Purpose: This study investigated discoloration and surface roughness (Ra) of resin-based computer aided design (CAD)/computer aided manufacturing (CAM) blocks and direct and indirect resin composites after staining with coffee. Materials &amp; Methods: Using a Teflon mold, 60 disc shaped specimens (8×2 mm2) were fabricated from direct (Estelite Asteria and GrandioSO) and indirect (Gradia Plus) resin composites, and 30 resin CAD/CAM specimens (12×14×2 mm3) were prepared from resin composite CAD/CAM blocks (Vita Enamic, Brilliant Crios, and Cerasmart) (n=10). A contact type profilometer was used to determine the Ra of all 60 polished samples. All specimens were thermocycled between 5 and 55°C for 3000 cycles, and immersed in coffee solution (37°C) for 1 and 7 days. A spectrophotometer was used to determine the color change (∆E00) with the CIEDE2000 formula after the specimens were re-polished. One-way analysis of variance (ANOVA) and Tukey multiple comparison test was performed to analyze the data (p&lt;0.05). Results: The lowest degree of discoloration among the materials tested was found in Vita Enamic resin CAD/CAM block (p&lt;0.001), whereas the highest degree of discoloration was found in the Gradia Plus indirect composite (p&lt;0.001). There was no significant difference was seen between the initial surface roughness values (Ra) among the groups (p=0.249). No significant improvement was observed in the color of the groups except for the Cerasmart resin block after after polishing. Conclusion: Direct resin composites have a higher discoloration potential over resin-based CAD/CAM blocks, whereas they are less prone to discoloration than indirect resin composites

Dental technology has developed materials for prosthetics that are very similar to natural teeth and offer a good balance between durability and esthetics; however, some of these materials are not very color-stable under the influence of external factors. Therefore, the aim of this study is to determine and compare the color change (∆E00) of different esthetic monolithic monochromatic CAD/CAM materials after they have been thermocycled and treated with staining solutions. The color parameters were determined using a spectrophotometer on a white and black background. Five CAD/CAM materials were used for this study-CAD/CAM nanoceramic (GC Cerasmart270), CAD/CAM lithium disilicate ceramic (IPS e.max CAD), CAD/CAM polymer (Telio CAD), CAD/CAM composite (Tetric CAD) and CAD/CAM polymer-infiltrated ceramic (Vita Enamic). The test specimens produced were divided into groups and were thermocycled in distilled water. They were then stored for four weeks at 37 °C in either distilled water as a control liquid, black tea, instant coffee or red wine. The aim is also to evaluate the color changes as a function of the exposure time of the staining solutions. The results obtained were analyzed statistically. All CAD/CAM materials tend to discolor to varying degrees. Among the factors contributing to discoloration, red wine proved to be the most significant influencing factor. The conclusion from the results is that the color change is influenced by the type of material, the staining solution, the sample thickness, the color background and the aging time.

To assess the clinical efficacy of posterior composite resin restorations placed directly and indirectly in posterior teeth after five years. A total of 108 cavities in 54 patients were restored with three direct composite resins (Filtek SupremeXT [FSXT], Tetric Evo Ceram [TEC], AELITE Aesthetic [AA]) and two indirect composite resins (Estenia [E] and Tescera ATL [TATL]). All restorations were evaluated by two examiners using the United States Public Health Service criteria at baseline and five years after placement. Statistical analysis was completed with Fisher exact and McNemar χ(2) tests. At baseline, 4% (five) of the restored teeth presented postoperative sensitivity; however, only one of them (a member of the E group) required canal treatment and replacement after two years. At the five-year evaluation, all restorations were retained, with Alpha ratings at 100%. Only one tooth (in the TEC group) required replacement after three years due to secondary caries. Color match, surface texture, and marginal integrity were predominantly scored as Alpha after five years for all groups. After that time, marginal discoloration was scored as Alpha in 64% of AE restorations, 70% of TATL restorations, 73% of E restorations, and 87% of FSXT restorations. There were no Charlie scores recorded for any of the restorative systems. Under controlled clinical conditions, indirect composite resin inlays and direct composite resin restorations exhibited an annual failure rate of 2.5% and 1.6%, respectively, after five years. Therefore, the investigated materials showed acceptable clinical performance, and no significant differences were found among them.

Comparison of translucency between indirect and direct resin composites

ObjectivesThis study evaluated color differences (ΔEs) and translucency parameter changes (ΔTPs) of various computer-aided design/computer-aided manufacturing (CAD/CAM) blocks after immersion in coffee.Materials and MethodsEight CAD/CAM blocks and four restorative composite resins were evaluated. The CIE L*a*b* values of 2.0 mm thick disk-shaped specimens were measured using the spectrophotometer on white and black backgrounds (n = 6). The ΔEs and ΔTPs of one day, one week, and one month immersion in coffee or water were calculated. The values of each material were analyzed by two-way ANOVA and Tukey's multiple comparisons (α = 0.05). The ΔEs after prophylaxis paste polishing of 1 month coffee immersion specimens, water sorption and solubility were also evaluated.ResultsAfter one month in coffee, ΔEs of CAD/CAM composite resin blocks and restorative composites ranged from 1.6 to 3.7 and from 2.1 to 7.9, respectively, and ΔTPs decreased. The ANOVA of ΔEs and ΔTPs revealed significant differences in two main factors, immersion periods and media, and their interaction except for ΔEs of TEL (Telio CAD, Ivoclar Vivadent). The ΔEs significantly decreased after prophylaxis polishing except GRA (Gradia Block, GC). There was no significant correlation between ΔEs and water sorption or solubility in water.ConclusionsThe ΔEs of CAD/CAM blocks after immersion in coffee varied among products and were comparable to those of restorative composite resins. The discoloration of CAD/CAM composite resin blocks could be effectively removed with prophylaxis paste polishing, while that of some restorative composites could not be removed.

Direct, indirect, and CAD/CAM composites are all susceptible to various degrees of discoloration and translucency changes after exposure to staining beverages. Red wine generally caused the most discoloration and translucency changes. Although CAD/CAM composites were more color stable than direct and indirect materials when exposed to red wine, color changes were still clinically perceptible.