Resin-matrix Ceramics Research Articles

The effects of whitening mouthrinses on the color stability of CAD/CAM resin matrix ceramics

Objective: This study aimed to evaluate the color change of CAD/CAM resin matrix ceramic, which was exposed to three different whitening mouth rinses and artificial saliva for 12 and 180 hours. Material and Methods: A total of 60 samples were produced from prefabricated CAD/CAM resin matrix ceramic blocks for experimental study. The samples were randomly divided into four subgroups according to the whitening mouthrinses: Listerine Advanced White, Colgate Optic White, Oral B 3D White Luxe, and artificial saliva. Spectrophotometric measurements were made from each sample at 3 different times, before (initial) exposure to mouthrinses, 12 hours and 180 hours after exposure (∆E001, ∆E002 and ∆E003). While using the generalized linear models method for the comparison of ∆E00, ∆L, ∆a, and ∆b color changes according to the mouthrinse and exposure time; multiple comparisons were made with the Tukey HSD Test. The significance level was taken as p<0.050. Results: The results of the two-way analysis of variance showed that the used mouthrinse and the exposure time had a statistically significant effect on the ∆E00 values representing the color change (p<0.001), while the interaction between the mouthrinse and the time of use did not play an important role (p=0.165). Conclusion: After exposure time of 180 hours, all whitening mouthrinses induce color change of resin matrix ceramics above clinically noticeable level.

Effect of Different Surface Treatments on Repair Bond Strength of CAD/CAM Resin-Matrix Ceramics.

The purpose of this study was to investigate the influence of different surface treatment methods on the micro-tensile bond strength (μTBS) of resin-matrix ceramic (RMC) blocks repaired with resin composite. Three different prefabricated RMC blocks including Lava Ultimate (LU), Grandio Blocs (GB), and Shofu Block HC (HC) were thermo-cycled and divided into five surface treatment groups: Control (C), bur grinding (G), airborne particle abrasion (APA), Er,Cr:YSGG laser irritation (LI), and APA combined with LI (APA+LI). After surface treatments, topographic alterations were examined by scanning electron microscopy. Then, Universal Adhesive (Single Bond Universal) was applied and repair was simulated with nanohybrid composite (Grandio SO). Bonded specimens were cut into 1 mm2 sized beams (n = 16) and a μTBS test was conducted by using a universal test machine. Fracture types were evaluated by using a stereomicroscope. The bond- strength data was evaluated by two-way ANOVA and Tukey post-hoc test (α = 0.05). The μTBS values were significantly affected by the surface treatment variable and the interaction terms of the variables (p ≤ 0.001). However, no significant effect of RMC type was detected (p > 0.05). Among all materials, GBAPA+LI indicated the highest µTBS value. Except for the GBC, all surface treatments showed clinically acceptable bond-strength values. However, the surface treatments applied to GB and LU before the repair processes increased the repair bond-strength values while causing a negative effect for HC. In addition, LI and APA+LI can be applied as an alternative route compared to other procedures recommended by the manufacturer for surface preparation in intraoral RMC repair.

Influence of Acidic Environment on the Hardness, Surface Roughness and Wear Ability of CAD/CAM Resin-Matrix Ceramics.

This study aimed to measure the effect of storage environment on the hardness, surface roughness and wear ability of CAD/CAM resin-matrix ceramics. A total of 200 rectangular-shaped specimens were obtained by sectioning 5 CAD/CAM blocks; Crystal Ultra (CU), Vita Enamic (VE), Lava Ultimate (LU), Cerasmart (CS) and Vita blocks Mark II (MII). Microhardness and surface roughness were measured at baseline and after 7 days of immersion either in saliva or cola (n = 10). The wear ability of the CAD/CAM materials against steatite-ceramics antagonist was determined using a chewing simulator. The data were statistically analyzed using factorial ANOVA followed by post hoc Bonferroni multiple comparison tests (p < 0.05). The independent factors significantly influenced the microhardness and surface roughness (p < 0.05). The highest VHN was observed in MII at baseline (586.97 ± 13.95), while CU showed the lowest VHN after 7 days of immersion in cola (68.3 ± 1.89). On the contrary, the highest Ra was observed after 120,000 chewing cycles for the VE specimens (1.09 ± 0.43 µm) immersed in cola, while LU showed the lowest Ra at baseline (0.07 ± 0.01 µm). The highest % mass loss of the antagonist was observed with MII immersed in cola (1.801%), while CS demonstrated the lowest % mass loss of 0.004% and 0.007% in AS and cola, respectively. This study confirms that the surface properties of tested CAD/CAM materials are susceptible to degradation in an acidic environment except for hardness and wear of CS material.

Assessment of relative translucency and resultant color of contemporary resin-matrix ceramics indicated for laminate veneers and full crowns.

Evaluation of the optical properties of restorative materials is an important parameter for identifying clinical success. The aim of this study was to compare the translucency of contemporary resin-matrix ceramics (RMCs) and to evaluate the effect of cement shade on the final color of RMCs indicated for laminate veneers and full crowns. A hundred A2 shade RMC specimens were fabricated by using Mazic Duro (MD), CAMouflage NOW (CN), KZR-CAD HR2 (KZR), Grandio Block (GB), and Brilliant Crios (BC) at 0.7-mm and 1.5-mm thicknesses (n = 10). A2 shade composite resin was used for the foundation structure. Twenty resin-cement specimens were prepared from A2 and translucent shades at 0.1-mm thickness. Interchangeably, the foundation-cement-resin matrix ceramic assemblies were created with optical gel. The color coordinates were recorded using a spectrophotometer. After calculating translucency parameter (TP00) and color difference (ΔE00) values, data were analyzed statistically (P = 0.05). TP00 values were influenced by RMC type and thickness. TP00 values of RMCs can be listed in descending order as MD>GB = CN>BC=KZR. ΔE00 values were significantly influenced by all parameters and their interactions. MD exhibited higher ΔE00 values among tested RMCs. The effect of A2 cement was not perceived visually while TR cement demonstrated visually perceptible but clinically acceptable values for both laminate veneers and full crowns. As the material thickness decreased, the TP00 and ΔE00 values increased in all RMCs. Clinicians should carefully prefer cement shade and RMC material by contemplating their impact on the optical properties particularly when the restoration is thin.

Effects of background color and thickness on the optical properties of CAD-CAM resin-matrix ceramics

Statement of problemInformation regarding the masking ability of computer-aided design and computer-aided manufacture (CAD-CAM) resin-matrix ceramic materials with different compositions is scarce. PurposeThe purpose of this in vitro study was to evaluate the effects of background color and thickness on the optical properties (color and translucency) of CAD-CAM resin-matrix ceramics. Material and methodsTwelve rectangular specimens were fabricated at a different thickness (1, 1.5, and 2 mm) (n=12) from each of the resin-matrix ceramic materials: Shofu block (SB), Lava Ultimate (LU), CERASMART (CS), VITA ENAMIC (VE), Crystal Ultra (CU), and the VITABLOCS Mark II feldspathic ceramic (VB). The color of the specimens over amalgam, titanium, enamel, and dentin backgrounds was measured with a spectrophotometer, and the color differences (ΔE∗ab) were calculated by using the Commission Internationale de l’Eclairage (CIE) 76 formula. The difference in color of the specimen over the black and white backgrounds was used to calculate the translucency parameter (TP). ANOVA was used to statistically test whether material, background, and thicknesses influenced ΔE∗ab and TP values. Post hoc comparisons were performed to determine the significant difference among the groups (α=.05). ResultsThe interaction with 2 between factors demonstrated that the material was a factor that significantly influenced ΔE∗ab (P<.001). The highest mean ±standard deviation of ΔE∗ab was recorded in the combination of VB material and 2-mm thickness (1.84 ±0.37), and the lowest with CS material with 1.5-mm thickness (0.47 ±0.24). The type of material and specimen thickness significantly influenced TP (P<.001). The highest and lowest mean ±standard deviation of TP were recorded for the 1-mm-thick CS (14.20 ±0.90) and 2-mm-thick SB (4.91 ±0.42) specimens, respectively. ConclusionsCERASMART resin-matrix ceramic and VITABLOCS Mark II feldspathic ceramic exhibited high and low masking abilities over the investigated background substrates, respectively. However, irrespective of the thickness, all study materials exhibited acceptable masking abilities.

Alternative surface treatments strategies for bonding to CAD/CAM resin-matrix ceramics

This study evaluated the shear bond strength (µSBS) and failure mode of CAD/CAM polymer-infiltrated ceramic network (PICN – Vita Enamic) and nanoceramic resin (NCR – Lava Ultimate) submitted to alternative surface treatments. 40 plates of each material were submitted to (n = 10) conventional (manufacturer’s indications): Sandblasting with Al2O3 (SAND) and 5% hydrofluoric acid etching (5% HF), or alternative treatments: 10% HF (10% HF) and Sandblasting + silanization (SAND/SIL). A self-etching adhesive system (Scotchbond Universal Adhesive, 3M Oral Care) was applied, and resin cement cylinders were built on the specimen’s treated surface and tested in µSBS after 24 h, or after water storage for 1 year. Data were evaluated by three-way repeated-measures ANOVA and Tukey test (α = 0.05). Failure mode was evaluated under scanning electron microscopy (SEM). At 24 h, HF etching (5% or 10%) promoted higher µSBS for PICN, while SAND and 5% HF promoted higher µSBS for NCR than SAND/SIL (p > 0.05). After storage for 1 year, all treatments decreased PICN’s bond strength, but 10% HF exhibited higher µSBS than 5% HF (p < 0.05). Also, 5% HF and SAND/SIL maintained µSBS of NCR, and in general, NCR exhibited higher µSBS than PICN. Failure mode was predominantly mixed after 24 h and mostly adhesive after 1-year storage. In conclusion, the surface treatments influenced the bond strength of PICN and NCR and 1-year storage decreased the bond strength for most groups. 10% HF is the treatment option for PICN while 5% HF-etching is an alternative to sandblasting for NCR.

Evaluation of surface characterization and mechanical features of resin-matrix ceramics before and after different surface treatments

Statement of problemSurface treatments (STs) required for micromechanical interlocking can lead to alterations in the surface characterization and mechanical features of the resin-matrix ceramics (RMCs), which may jeopardize the long-term outcome of an indirect restoration. However, evidence on this issue is lacking. PurposeThe purpose of this in vitro study was to assess the influence of different STs on the surface roughness (SR), water contact angle (WCA), and flexural strength (FS) of RMCs. Material and methodsTwo hundred rectangular plates (12×14×1 mm) were prepared from 5 different RMC ingots, including a polymer-infiltrated ceramic network (Vita Enamic [VE]), 2 resin nanoceramics (Lava Ultimate [LU], Grandio Blocks [GB]), a flexible nanoparticle-filled resin (GC Cerasmart [GC]), and a reinforced composite resin (Brilliant Crios [BC]). Plates of each RMC group were further divided into 4 subgroups according to the ST applied: Control, no treatment (C); airborne-particle abrasion with aluminum oxide particles (APA); 2W- and 3W-Er,Cr:YSGG laser irradiations (LI2W, LI3W) (n=10 per ST). The SR (Ra) of each plate was recorded with a contact profilometer. WCAs (θ) of distilled water on the plates were determined by using the sessile-drop method. The FS (MPa) of each plate was measured with a universal testing machine. Data acquired for SR, WCA, and FS were statistically analyzed (α=.05). Weibull statistics were also conducted to determine the reliability of each material. ResultsThe 2-way ANOVA showed that SR, WCA, and FS values were significantly influenced not only by all tested variables but also by their interaction terms (P<.001). All STs significantly increased the SR values (P<.05). Maximum and minimum SR values were recorded in GC-LI3W (7.06 ±0.16) and GC-C (0.07 ±0.02) groups. After STs, WCA values significantly diminished (P<.05). Maximum and minimum WCA values were recorded in LU-C (61.74 ±2.45) and VE-APA (40.38 ±1.56) groups. All STs significantly reduced the FS values (P<.05). The upper and lower FS bounds were 140.7 ±17.07 and 60.66 ±6.31, respectively, set by VG-C and GC-APA. Weibull distribution indicated that the untreated groups presented the highest m values. Among the treated groups, BC-LI3W demonstrated superior reliability (m=14.04). ConclusionsAPA for LU, LI2W for VG and BC, and LI3W for GC and VE can be preferred. Although APA increased the SR and provided more wettable surfaces, it caused considerable loss of FS. Therefore, LI can be recommended as a safer ST for RMCs.

Optical Behavior and Surface Analysis of Dental Resin Matrix Ceramics Related to Thermocycling and Finishing

Color preservation of esthetic dental restorative materials in the oral environment represents, besides longevity, a concern, and there is still limited knowledge related to the effect of aging on the optical behavior of resin matrix ceramics. The study analyzed the finishing and thermocycling of resin matrix ceramic material surfaces, in order to assess their consequences on optical properties. Five resin matrix CAD/CAM ceramics, namely a polymer-infiltrated ceramic and four types of nanoparticle-filled resins, were selected for the study, and finished by polishing and glazing. Thermocycling was chosen as the in vitro aging method. Surface microroughness, optical and hardness evaluations were achieved before and after artificial aging. Statistical analyses were performed with IBM SPSS Statistics software at a significance value of p &lt; 0.05. Micro-roughness values increased after thermocycling, but were kept under the clinically accepted values. The optical characteristics of resin matrix ceramics were not significantly modified by thermocycling. Values of the glazed samples became closer to those of the polished ones, after hydrothermal aging, even if the differences were insignificant. Thermocycling significantly decreased the microhardness, mainly for glazed samples. This could be the consequence of glaze removal during thermocycling, which means that glazes provide a surface protection for a limited time.

Evaluation of the Effect of Cement Shade and Accelerated Artificial Aging on Color Stability of CAD/CAM Resin-matrix Ceramics: An In Vitro Study

Evaluation of the Effect of Cement Shade and Accelerated Artificial Aging on Color Stability of CAD/CAM Resin-matrix Ceramics: An In Vitro Study

Clinical performance of resin-matrix ceramic partial coverage restorations: a systematic review.

ObjectiveTo evaluate clinical performance of the new CAD/CAM resin-matrix ceramics and compare it with ceramic partial coverage restorations.Materials and methodsAn electronic search of 3 databases (The National Library of Medicine (MEDLINE/PubMed), Scopus, and the Cochrane Central Register of Controlled Trials) was conducted. English clinical studies published between 2005 and September 2020 that evaluated the clinical performance of CAD/CAM resin-matrix ceramics inlays, onlays, or overlays were selected. The primary clinical question was applied according to PICOS strategy (Population, Intervention, Comparison, Outcome, Study design). The included studies were individually evaluated for risk of bias according to the modified Cochrane Collaboration tool criteria.ResultsA total of 7 studies were included according to the established inclusion and exclusion criteria. From the included studies, 6 were randomized clinical trials while one study was longitudinal observational study without control group. According to the results of the included studies, the success rate of CAD/CAM resin-based composite ranged from 85.7 to 100% whereas the success rate reported for ceramic partial coverage restorations ranged from 93.3 to 100%. Fractures and debondings are found to be the most common cause of restorations failure.ConclusionCAD/CAM resin-based composite can be considered a reliable material for partial coverage restorations with clinical performance similar to glass ceramic restorations. However, this result needs to be confirmed in long-term evaluations.Clinical relevanceCAD/CAM resin-based composites provide a potential alternative to ceramic indirect restorations. However, clinicians must be aware of the lake of knowledge regarding long-term outcome.

Evaluation of the effects of different surface modification methods on the bond strength of high-performance polymers and resin matrix ceramics.

The purpose of this in vitro study was to investigate the effects of various surface treatment methods on the shear bond strength of self-adhesive resin cement to polymer-infiltrated materials. One hundred twenty-eight polymer-infiltrated specimens (n = 32) for four different computer aided design-computer-aided manufacturing (CAD-CAM) materials, polyether ether ketone (PEEK) (PE), polyether ketone ketone (PEKK) (PK), composite resin nanoceramic (Cerasmart) (CS), and polymer-infiltrated ceramic network (PICN) (VITA ENAMIC) (VE) were milled from CAD-CAM blocks. They were divided into two groups (n = 16) in terms of surface treatments: airborne-particle abraded (AA) or silica-coated (SC) and two subgroups (n = 8) according to adhesive application or no adhesive. The surface roughness, contact angle, and shear bond strength (SBS) values of specimens were measured. Data were analyzed with Shapiro-Wilk test, the generalized linear models' method, and Bonferroni corrected t test (α ˂ 0.05). No statistically significant differences were found between the groups in terms of surface roughness and SBS values (P > 0.05). A statistically significant effect of the main adhesive interaction on the bond strength was found independent of the material and surface treatments (P < 0.001). While the average bond strength of the non-adhesive was 4.9MPa, the average of the adhesive applied was 9.1MPa. On the other hand, there is a statistically significant difference between the means of the contact angle values (P ˂ 0.001). While the highest mean contact angle value was 117.1 ± 14.8° obtained from the non-adhesive PK in the AA group, the lowest mean contact angle value 22.6 ± 4.3° was obtained from the VE without adhesive in the SC group. Roughness and SBS values were similar between groups after surface treatments. Adhesive application increased the SBS values. Surface treatments were found to have an effect on the contact angle. Since the AA and SC surface treatments used in the study show similar bond strength values, the Cojet system, which is more practical and easier to use, can be preferred as an alternative to AA after restoration production with CAD-CAM as a chairside.

The effect of resin cement shade and restorative material type and thickness on the final color of resin-matrix ceramics

This study aims to evaluate the effects of cement shade, restorative material type, and thickness on the final color of resin-matrix ceramics. Ninety A2 shade resin-matrix ceramic specimens were prepared from Vita Enamic, GC Cerasmart, and Lava Ultimate at 0.5 and 1.0 mm thicknesses. Sixty resin cement disks were fabricated from different shades (A1, A3O, B05, and TR) of RelyX Ultimate at 0.1 mm thickness. CIE color coordinates were measured using a spectrophotometer, and color differences (∆E00) were calculated. Data were statistically analyzed (P =0.05). The ΔE00 values were influenced by the cement shade, restorative material type, thickness, and their interactions (P < 0.05). A3O cement caused clinically unacceptable values for all groups at 0.5 mm thickness and GC at 1.0 mm thickness. A1 and TR cement shades demonstrated visually perceptible but clinically acceptable values, except for VE-A1 and LU-A1 at 0.5 mm thickness. The ∆E00 values of the B05 cement shade were lower than the visually perceptible threshold for both thicknesses except for GC at 0.5 mm thickness. The shade of the resin cement and the type and thickness of the resin-matrix ceramic material significantly affected the resulting final color. To provide a shade matching with natural dentition and to obtain esthetic restorations, especially for the anterior teeth, the resin cement shade and resin-matrix ceramic material should be carefully selected.

Survival of implant-supported resin-matrix ceramic crowns: In silico and fatigue analyses

ObjectiveTo evaluate the fatigue survival, failure mode, and maximum principal stress (MP Stress) and strain (MP Strain) of resin-matrix ceramic systems used for implant-supported crowns. MethodsIdentical molar crowns were milled using four resin-matrix ceramics (n = 21/material): (i) Shofu Hard, (ii) Cerasmart (iii) Enamic, and (iv) Shofu HC. Crowns were cemented on the abutments, and the assembly underwent step-stress accelerated-life testing. Use level probability Weibull curves at 300 N were plotted and the reliability at 300, 500 and 800 N was calculated for a mission of 50,000 cycles. Fractographic analysis was performed using stereomicroscope and scanning electron microscope. MP Stress and MP Strain were determined by finite element analysis. ResultsWhile fatigue dictated failures for Cerasmart (β > 1), material strength controlled Shofu Hard, Enamic, and Shofu HC failures (β < 1). Shofu HC presented lower reliability at 300 N (79%) and 500 N (59%) than other systems (>90%), statistically different at 500 N. Enamic (57%) exhibited a significant reduction in the probability of survival at 800 N, significantly lower than Shofu Hard and Cerasmart; however, higher than Shofu HC (12%). Shofu Hard and Cerasmart (>93%) demonstrated no significant difference for any calculated mission (300–800 N). Failure mode predominantly involved resin-matrix ceramic fracture originated from occlusal cracks, corroborating with the MP Stress and Strain location, propagating through the proximal and cervical margins. SignificanceAll resin-matrix ceramics crowns demonstrated high probability of survival in a physiological molar load, whereas Shofu Hard and Cerasmart outperformed Enamic and Shofu HC at higher loads. Material fracture comprised the main failure mode.

Micro-shear bond strengths of resin-matrix ceramics subjected to different surface conditioning strategies with or without coupling agent application.

PURPOSEThis study aimed to assess the influence of various micromechanical surface conditioning (MSC) strategies with or without coupling agent (silane) application on the micro-shear bond strength (µSBS) of resin- matrix ceramics (RMCs).MATERIALS AND METHODSGC Cerasmart (GC), Lava Ultimate (LU), Vita Enamic (VE), Voco Grandio (VG), and Brilliant Crios (BC) were cut into 1.0-mm-thick slices (n = 32 per RMC) and separated into four groups according to the MSC strategy applied: control-no conditioning (C), air-borne particle abrasion with aluminum oxide particles (APA), 2W- and 3W-Er,Cr:YSGG group coding is missing. The specimens in each group were further separated into silane-applied and silane-free subgroups. Each specimen received two resin cement microtubules (n = 8 per subgroup). A shear force was applied to the adhesive interface through a universal test machine and µSBS values were measured. Data were statistically analyzed by using 3-way ANOVA and Tukey HSD test. Failure patterns were scrutinized under stereomicroscope.RESULTSRMC material type, MSC strategy, and silanization influenced the µSBS values (P<.05). In comparison to the control group, µSBS values increased after all other MSC strategies (P<.05) while the differences among these strategies were insignificant (P>.05). For control and APA, there were insignificant differences between RMCs (P>.05). The silanization decreased µSBS values of RMCs except for VE. Considerable declines were observed in GC and BC (P<.05).CONCLUSIONMSC strategies can enhance bond strength values at the RMC - cement interface. However, the choice of MSC strategy is dependent on RMC material type and each RMC can require a dedicated way of conditioning.

Resin matrix ceramics – mechanical, aesthetic and biological properties

ABSTRACT Resin matrix ceramics consist in a polymeric matrix with predominantly inorganic refractory compounds which may include porcelain, glass, ceramics, and glass ceramics, and are divided into three subgroups: Nanoceramics, Vitroceramics, and Zirconia-silica. The aim of this study was to compare, through a literature review, the mechanical and biological properties of resin matrix ceramics, with glass matrix ceramics and polycrystalline ceramics. After reviewing 44 articles found in the US National Library of Medicine (PubMed) database (studies published in English, human clinical studies, in vitro or in vivo studies) that evaluated some properties of this material, such as elasticity modulus, wear resistance, adhesiveness, stain resistance and hardness, this article concluded that, although they belong to the same group, resin matrix ceramics are different from each other due to their microstructures. Moreover, when compared to other ceramic groups, it showed some superior properties, such as flexural strength, fatigue strength and internal adaptation.

The effect of silane and universal adhesives on the micro-shear bond strength of current resin-matrix ceramics.

PURPOSEThe aim of this in vitro study was to evaluate the effect of silane and universal adhesive applications on the micro-shear bond strength (µSBS) of different resin-matrix ceramics (RMCs).MATERIALS AND METHODSA total of 120 slides (14 × 12 × 1 mm) were produced from 5 different RMC materials (GC Cerasmart [GC]; Brilliant Crios [BC]; Grandio blocs [GB]; Katana Avencia [KA]; and KZR-CAD HR 2 [KZR]) and sandblasted using 50 µm Al2O3 particles. Each RMC material was divided into six groups according to the surface conditioning (SC) method as follows: control (G1), silane primer (G2), silane-free universal adhesive (G3), silane-containing universal adhesive (G4), silane primer and silane-free universal adhesive (G5), and silane primer and silane-containing universal adhesive (G6). Three cylindric specimens made from resin cement (Bifix QM) were polymerized over the treated surface of each slide (n = 12). After thermal cycling (10000 cycles, 5 – 55℃), µSBS test was performed and failure types were evaluated using a stereomicroscope. Data were analyzed using 2-way ANOVA and Tukey tests (α = .05).RESULTSµSBS values of specimens were significantly affected by the RMC type and SC protocols (P < .001) except the interaction (P = .119). Except for G2, all SC protocols showed a significant increase in µSBS values (P < .05). For all RMCs, the highest µSBS values were obtained in G4 and G6 groups.CONCLUSIONOnly silane application did not affect the µSBS values regardless of the RMC type. Moreover, the application of a separate silane in addition to the universal adhesives did not improve the µSBS values. Silane-containing universal adhesive was found to be the best conditioning method for RMCs.

Influence of background shade and resin cement on color change of resin matrix ceramics

ENWEndNote BIBJabRef, Mendeley RISPapers, Reference Manager, RefWorks, Zotero AMA Batak B, Öztürk C. Influence of background shade and resin cement on color change of resin matrix ceramics. Journal of Stomatology. 2021;74(3):160-165. doi:10.5114/jos.2021.108956. APA Batak, B., & Öztürk, C. (2021). Influence of background shade and resin cement on color change of resin matrix ceramics. Journal of Stomatology, 74(3), 160-165. https://doi.org/10.5114/jos.2021.108956 Chicago Batak, Burcu, and Caner Öztürk. 2021. "Influence of background shade and resin cement on color change of resin matrix ceramics". Journal of Stomatology 74 (3): 160-165. doi:10.5114/jos.2021.108956. Harvard Batak, B., and Öztürk, C. (2021). Influence of background shade and resin cement on color change of resin matrix ceramics. Journal of Stomatology, 74(3), pp.160-165. https://doi.org/10.5114/jos.2021.108956 MLA Batak, Burcu et al. "Influence of background shade and resin cement on color change of resin matrix ceramics." Journal of Stomatology, vol. 74, no. 3, 2021, pp. 160-165. doi:10.5114/jos.2021.108956. Vancouver Batak B, Öztürk C. Influence of background shade and resin cement on color change of resin matrix ceramics. Journal of Stomatology. 2021;74(3):160-165. doi:10.5114/jos.2021.108956.

Influence of Low-Pressure Plasma on the Surface Properties of CAD-CAM Leucite-Reinforced Feldspar and Resin Matrix Ceramics

The introduction of new ceramic materials for dental restorations is currently a reality; however, little information is available on their surface treatment for the bonding process. Furthermore, surface treatment with plasma on ceramic materials has been recently introduced, although not many studies are available. The aim of this study was to evaluate the surface properties of a leucite-reinforced feldspar ceramic (LIC) and resin matrix ceramic (RMC) after low-pressure plasma treatment. From each material, 48 discs were prepared and subject to surface treatment. The LIC group was treated by hydrofluoric acid (HF) (LIC-HF), plasma with oxygen (LIC-O2), and plasma with argon (LIC-Ar). The RMC group was treated by sandblasting with alumina (RMC-SB), plasma with oxygen (RMC-O2), and plasma with argon (RMC-Ar). The groups whose surfaces were not subjected to treatment were considered as the control group. Surface wettability and roughness was analyzed. The results showed significant differences among the treatments for both ceramics regarding wettability and roughness. Plasma treatments increased the wettability and had a very low effect on the roughness. Plasma treatments achieved similar values for both surface properties in each ceramic group with no differences between both treatments. Plasma treatment seems to be a promising alternative for ceramic surface treatments since it increased the surface energy of the ceramics analyzed and hardly affects the roughness. Further studies are necessary to evaluate the effect of plasma treatment on the bond strength of ceramics.

Resin-matrix ceramics for occlusal veneers: Effect of thickness on reliability and stress distribution

ObjectiveTo evaluate the influence of resin-matrix ceramic material and thickness on reliability and stress distribution of occlusal veneers (OV). MethodsOne hundred and twenty-six OV of a mandibular first molar were milled using a CAD/CAM system and allocated according to materials (resin nanoceramic (RNC) or polymer-infiltrated ceramic network (PICN)) and thicknesses (0.5, 1.0 and 1.5 mm), totaling six groups (RNC0.5, RNC1, RNC1.5, PICN0.5, PICN1, and PICN1.5). Step-stress accelerated-life testing was performed (n = 21/group) with the load applied at the distobuccal cusp tip of the occlusal veneer until failure or suspension. The use level probability Weibull curves and reliability were calculated and plotted (90% CI). Finite element analysis evaluated the stress distribution according to maximum principal stress (σmax) on the restoration and maximum shear stress (τmax) on the cement layer. ResultsThere was no difference in the probability of survival for the estimated missions among the groups, except at 600 N in which the results were significantly lower to PICN1.5 (6%) compared to RNC1 (55%) and RNC1.5 (60%). The σmax values were higher for PICN (31.85–48.63 MPa) than RNC (30.78–33.09 MPa) in the same thicknesses. In addition, 0.5 mm groups concentrated more stress in the restoration (33.09–48.63 MPa) than 1.0 mm (31.11–35.36 MPa) and 1.5 mm (30.78–31.85 MPa) groups in the same material. SignificanceBoth resin-matrix ceramic materials seem up-and-coming restorative systems for occlusal veneers irrespective of the thicknesses as a consequence of the high reliability.

Effect of color of the cement and the composite resin foundation on the resultant color of resin-matrix ceramics

Statement of problemAn improper restoration color match to the adjacent natural teeth can jeopardize esthetic success. The type of resin-matrix ceramic (RMC), the shade of the underlying foundation, and the shade of cement may affect the optical behavior of RMC materials, but studies on this issue are lacking. PurposeThe purpose of this in vitro study was to assess the cumulative effect of different shades of composite resin foundation (CRF) and cement on the optical behaviors of 3 different RMCs. Material and methodsForty-five rectangular RMC specimens (14×12×1 mm, shade A2) were prepared from 3 different blocks, including a polymer-infiltrated ceramic network (Vita Enamic [VE]), a resin nanoceramic (Lava Ultimate [LU]), and a flexible nanoparticle-filled resin (GC Cerasmart [GC]) (n=15 per RMC block). CRFs (14×12×4 mm) were fabricated in white and dentin shades (n=1 per composite resin shade). Cement specimens (G-CEM LinkForce) were prepared from 3 shades (A2, opaque [OP], and translucent [TR]) (n=15 per shade). For control groups, 3 rectangular RMC foundations (14×12×4 mm) were also milled from RMC blocks (n=1 per block). Color coordinates were recorded by using a digital spectrophotometer. The coordinates of 4-mm-thick RMC foundations served as the control groups. The coordinates of RMC specimens on each combination of CRF and cement served as test groups. The CIEDE2000 (ΔE00) formula was used to assess color differences. Data were subjected to 3-way ANOVA and Tukey honestly significant difference (HSD) tests (α=.05). ResultsΔE00 values of specimens were influenced by the CRF shade, cement shade, RMC type, as well as the interaction terms of the 3 variables (P<.001). Color differences in groups VE-A2-dentin, VE-OP-dentin, LU-OP-dentin, and GC-OP-dentin showed perceptible but clinically acceptable values (0.8<ΔE00≤1.8). The highest and lowest ΔE00 values were observed in the white-OP-LU (5.32 ±0.34) and dentin-OP-VE (0.94 ±0.31) groups. ConclusionsOpaque cement on the white foundation led to the highest ΔE00 values in the resultant colors of all RMC groups. When used with the same shade on the dentin foundation, this cement produced clinically acceptable results.