A 48-month clinical performance of hybrid ceramic fragment restorations manufactured in CAD/CAM in non-carious cervical lesions: case report.

From the restorative perspective, various methods are available to prevent the progression of non-carious cervical lesions. Direct, semi-direct, and indirect composite resin techniques and indirect ceramic restorations are commonly recommended. In this context, semi-direct and indirect restoration approaches are increasingly favored, particularly as digital dentistry becomes more prevalent. To illustrate this, we present a case report demonstrating the efficacy of hybrid ceramic fragments fabricated using computer-aided design (CAD)/computer-aided manufacturing (CAM) technology and cemented with resin cement in treating non-carious cervical lesions over a 48-month follow-up period. A 24-year-old male patient sought treatment for aesthetic concerns and dentin hypersensitivity in the cervical region of the lower premolar teeth. Clinical examination confirmed the presence of two non-carious cervical lesions in the buccal region of teeth #44 and #45. The treatment plan involved indirect restoration using CAD/CAM-fabricated hybrid ceramic fragments as a restorative material. After 48 months, the hybrid ceramic material exhibited excellent adaptation and durability provided by the CAD/CAM system. This case underscores the effectiveness of hybrid ceramic fragments in restoring non-carious cervical lesions, highlighting their long-term stability and clinical success.

Effect of Resin Cement Viscosities and Surface Roughness on Shear Bond Strength of Conditioned Polymer Infiltrated Ceramic Network.

BACKGROUND: Hybrid ceramics bonding with the dentinal substrate is crucial for clinical success and longevity. To enhance adhesion, the surface of ceramic restorations is modified through various conditioning techniques AIM: Effect of Different Surface Conditioners Erbium-doped yttrium aluminum garnet (ER: YAG) laser and Low-level laser therapy (LLLT) activated Methylene blue (MB) on the surface roughness (Ra) and shear bond strength (SBS) of Polymer infiltrating ceramic network (PICN) discs bonded using different viscosity resin cement before and after thermal aging. MATERIAL AND METHODS: One hundred and fifty human central incisors and one hundred and fifty-three PICN discs were prepared. PICN discs were randomly allocated into three groups based on the surface conditioning(n=51) Group 1:10% HF acid-S, Group 2: LLLT (MB), and Group 3: Er: YAG laser. Following conditioning Ra scores of ten samples were performed. Surface topography of samples was performed using a scanning electron microscope (SEM). Bonding of forty PICN discs from each conditioning group was performed with high (A) or low viscosity (B) dual-curing resin cement (n= 20 each). Each subgroup was divided into two cohorts and subjected to varying storage conditions. The SBS test and failure mode analysis were performed using a universal testing machine and stereomicroscope. Descriptive statistics of SBS and Ra for each group were analyzed using ANOVA and Tukey post hoc tests. HF acid-S attained the highest Ra scores. RESULTS: Group 1A (HF-S+HIGH) samples achieved the highest SBS values at baseline. Group 3A, on the other hand, displayed the lowest bond score (Er: YAG laser+HIGH) after thermal aging. Intergroup comparison analysis at baseline unveiled that Group 1A and Group 1B (HF(S) + LOW) displayed no significant difference in their bond strength scores (p>0.05). Following artificial aging, it was observed that Group 2A (LLLT (MB) + HIGH) and Group 3A (Er:YAG laser + HIGH) ) presented comparable SBS(p>0.05). Thermal aging decreased SBS significantly in all groups. PICN conditioned with HF-S results in high surface roughness. CONCLUSION: PICN conditioned with HF acid with silane and bonded with low-viscosity resin cement to the dentinal substrate is preferable. Aging influences SBS.

First-principles calculations on dislocations in MgO.

While ceramic materials are widely used in our society, their understanding of the plasticity is not fully understood. MgO is one of the prototypical ceramics, extensively investigated experimentally and theoretically. However, there is still controversy over whether edge or screw dislocations glide more easily. In this study, we directly model the atomic structures of the dislocation cores in MgO based on the first-principles calculations and estimate the Peierls stresses. Our results reveal that the screw dislocation on the primary slip system exhibits a smaller Peierls stress than the edge dislocation. The tendency is not consistent with metals, but rather with TiN, suggesting a characteristic inherent to rock-salt type materials.

Performing highly accurate computational methods ­ specifically, a combination of direct atomic modeling and first-principles calculations ­ to estimate the Peierls stresses of MgO.

Plasmonic group IVB transition metal nitrides: Fabrication methods and applications in biosensing, photovoltaics and photocatalysis.

This review paper focuses on group IVB transition metal nitrides (TMNs) such as titanium nitride (TiN), zirconium nitride (ZrN), and hafnium nitride (HfN) and as alternative plasmonic materials to noble metals like gold and silver. It delves into the fabrication methods of these TMNs, particularly emphasizing thin film fabrication techniques like magnetron sputtering and atomic layer deposition, as well as nanostructure fabrication processes applied to these thin films. Overcoming the current fabrication and application-related challenges requires a deep understanding of the material properties, deposition techniques, and application requirements. Here, we discuss the impact of fabrication parameters on the properties of resulting films, highlighting the importance of aligning fabrication methods with practical application requirements for optimal performance. Additionally, we summarize and tabulate the most recent plasmonic applications of these TMNs in fields like biosensing, photovoltaic energy, and photocatalysis, contributing significantly to the current literature by consolidating knowledge on TMNs.

Impedance Spectroscopy of Sm-Doped of BaBi2Nb2O9 Aurivillius Ceramics.

This investigation focuses on the impact of Sm3+ dopants on BaBi2Nb2O9 (BBN) ceramics. These ceramics were obtained using the traditional solid state reaction approach. Techniques like scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) were employed to explore the structure and morphology of the ceramics. The results showed that the chemical composition of the ceramic samples matched well with the initial ceramic powder stoichiometry. Increasing the amount of samarium resulted in a slight reduction in the average ceramic grain size. The ceramics exhibited a tetragonal structure categorized under the space group I4/mmm. The electrical properties were analyzed using complex impedance spectroscopy (SI) across various temperatures and frequencies, revealing that both grains and intergranular boundaries are significant in the material's conductivity.

Evaluation and comparison of four types of bio-ceramic materials AGM MTA, Ortho MTA, pro root MTA and Cem cement in oral and dental health.

BACKGROUND AND OBJECTIVES: Mineral Trioxide Aggregate (MTA) is one of the main retrograde filling materials that is used today as a root end filling material and perforation repair material. This study was conducted with the aim of investigating the antibacterial and antifungal properties of four types of bio-ceramic materials, AGM MTA, Ortho MTA, Pro root MTA and Cem cement for oral and dental health. METHODS: In this study, the antibacterial activity of four types of bio-ceramic materials against two bacterial strains of Enterococcus faecalis (ATTC 29212), Escherichia coli (ATTC 35318) and antifungal activity against Candida albicans (ATTC 10231) were investigated using the well diffusion method. RESULTS: In the context of the relationship between the type of microorganism and the diameter of the growth inhibitory zone for each type of bio-ceramic material, there was no significant difference for Enterococcus faecalis, and a significant difference was observed for Escherichia coli and Candida albicans (p < 0.05). CONCLUSION: The results show that each of the bio-ceramic materials AGM, Pro root, Cem cement and Ortho have antibacterial and antifungal properties. AGM MTA bio-ceramic material on Candida albicans fungus and Ortho MTA bio-ceramic material had the most effect on Escherichia coli bacteria. Therefore, the mentioned bio-ceramic materials can play a significant role in oral and dental health by providing a suitable material for restoration.

A novel simplified method for assessing crystal length and crystalline content in dental ceramics.

The purpose of this study was to introduce a novel and simple method of evaluating the crystal length and crystalline content of lithium disilicate dental ceramics using images obtained from scanning electron microscopy (SEM) and analyzed with ImageJ (NIH) processing software. Three evaluators with varying experience levels assessed the average crystal length and percentage of crystalline content in four commercial lithium disilicate reinforced glass ceramic materials: IPS e.max (Ivoclar Vivadent), Rosetta SM (Hass), T-Lithium (Talmax), and IRIS CAD (Tianjin). The specimens, prepared from partially crystallized CAD/CAM blocks (3.0 mm3), were fully crystallized and treated with 5% hydrofluoric acid for 20 s prior to SEM analysis. After acquiring the SEM images, ImageJ software was used to evaluate the average crystal length and crystalline content on the surface of the different ceramics. An inter-operator agreement was observed (ICC/p = 0.724), indicating that assessments by the various operators were similar across all ceramic materials tested (p < 0.001). When crystal length and crystalline content were compared, IRIS CAD exhibited significant differences compared to the other materials (p < 0.001), showing a less dense crystalline matrix based on the average length of crystals and the percentage of crystals per unit area. The use of this software facilitated the evaluation of crystalline content and average crystal lengths in dental ceramics using SEM images, and demonstrated very low variability among different operators. RESEARCH HIGHLIGHTS: The described method, using ImageJ open-source software, provides precise and reliable measurements of crystal length and crystalline content in lithium disilicate ceramics, with high inter-operator agreement. The proposed method identified higher crystalline content in IPS e.max CAD compared to Rosetta SM CAD and T-lithium CAD ceramics, while IRIS CAD exhibited significantly lower crystalline content and larger average crystal length. The novel, simplified method for assessing crystal length and crystalline content presented in this study may also be useful for evaluating other dental ceramics.

Evaluation of zirconia ceramics fabricated through DLP 3d printing process for dental applications.

Zirconia ceramics are versatile materials with remarkable properties such as a high thermal resistance, high fracture strength, and low thermal conductivity. They are chemically inert and highly wear- and corrosion-resistant, making them ideal for a wide range of applications in the aerospace, automotive, and biomedical fields. In dentistry, zirconia ceramics are used for veneers, crowns, bridges, and implants because of their biocompatibility. Despite the various benefits of zirconia ceramics, they are difficult to process because of their high hardness and brittleness. Additive manufacturing (AM) has proven to be a viable alternative to conventional fabrication processes, particularly for the processing of difficult-to-cut materials. AM of ceramics has gained significant attention in recent years because of its flexibility and ability to produce customized geometries rapidly and economically. In this study, the digital light processing (DLP) technique was employed to 3D print yttria-stabilized zirconia. The fabricated zirconia was evaluated and characterized for use in dental applications. Thermogravimetric analysis (TGA) and differential thermogravimetry (DTG) were performed on the green body to assess the decomposition of the additives in the slurry and determine the debinding temperatures. The as-built parts were subjected to debinding and sintering to obtain fully dense zirconia parts. The parts tended to shrink after sintering; therefore, the shrinkage ratios were evaluated and found to be 1.2817, 1.2900, and 1.3388 in the x-, y-, and z-directions, respectively. The average density after sintering was 6.031 g/cc. The flexural strength determined using four-point bending tests was 451.876 MPa, and the tensile and compressive strengths were 143 MPa and 298.4 MPa, respectively.

Longevity and risk factors of CAD-CAM manufactured implant-supported all-ceramic crowns - A prospective, multi-center, practice-based cohort study.

OBJECTIVES: The aim of this prospective, multi-center, practice-based cohort study was to analyze factors associated with the success of implant supported all-ceramic single-unit crowns, made by computer-aided-design/computer-aided-manufacturing (CAD-CAM). METHODS: All-ceramic crowns placed in a private practice-based research network (Ceramic Success Analysis, AG Keramik) were analyzed. Data from 567patients with CAD-CAM implant supported all-ceramic crowns placed between 2008-2023 by 54dentists were evaluated. Firstly, all crowns with at least one follow-up control were included (n = 907). Secondly, all crowns being followed up for ≥ 5years and all failures were included (n = 151). At the latest follow-up visit, crowns were considered as successful (not failed) if they were still in function without the need for additional therapy. Multi-level Cox proportional hazards models were used to evaluate the association between a range of predictors and time of success. RESULTS: Within a mean follow-up period (SD) of 2.5 (2)years (first scenario) and 6.2 (1.2)years (second scenario) [maximum:12years], 27crowns failed (annual failure rate [AFR]:0.74 %). The main failure types were decementation, (n = 11), fracture of the ceramic (n = 4) or Ti-Base (n = 4). In 5-year-scenario, crowns fabricated in the laboratory had 26times lower failure rate than those fabricated chairside (95 %CI:0.0-0.7;p = 0.038). Furthermore, the use of a silane (HR:0.051;95 %CI:0.0-0.5;p = 0.014) and etching of the ceramic (HR:0.053;95 %CI:0.0-0.8;p = 0.035) resulted in a significantly higher risk for failure than their non-use. SIGNIFICANCE: For CAD-CAM manufactured implant supported all-ceramic crowns, high success rates were found in up to 12-year evaluation. Furthermore, after 5years, no patient-or implant-level factors, but operative-level factor (i.e.fabrication method, use of silane/etching) were significantly associated with failure. The study was registered in the German Clinical Trials Register (DRKS-ID: DRKS00020271).

Simultaneous Improvement of Energy Storage Characteristics and Temperature Stability in K0.5Na0.5NbO3-Based Ceramics via LiF Modification.

The splendid energy storage performances with eminent stability of dielectric ceramics utilized in pulsed power devices have been paid more attention by researchers. This scheme can be basically realized through introducing Li+, Bi(Mg2/3Ta1/3)O3, NaNbO3, and LiF into KNN-based ceramics. Under the breakdown strength (BDS) of 460 kV/cm, an outstanding energy storage density (W) of 6.05 J/cm3 with a high energy efficiency (η) of 85.9% is implemented. Within the broad temperature range from 20 to 140 °C, the numerical fluctuations of energy storage characteristics can be maintained at a relatively stable level (ΔWrec ≈ 3.5%, Δη ≈ 2.8%). As for the charging-discharging performances, this component possesses a fast discharging speed (t0.90 ≈ 51 ns) and remarkable temperature stability (the variations are smaller than 3.5%). Additionally, the internal mechanisms of outstanding energy storage properties can be confirmed via crystal structures and domain structures, the content of oxygen vacancies, dielectric and impedance spectra, and phase simulation. Hence, the combination of outstanding energy storage with remarkable thermal stability can be fulfilled in one ceramic system according to this discovery, providing a research thought of developing the materials for dielectric capacitors.

Giant Capacitive Energy Storage in High-Entropy Lead-Free Ceramics with Temperature Self-Check.

Considering the large demand for electricity in the era of artificial intelligence and big data, there is an urgent need to explore novel energy storage media with higher energy density and intelligent temperature self-check functions. High-entropy (HE) ceramic capacitors are of great significance because of their excellent energy storage efficiency and high power density (PD). However, the contradiction between configurational entropy and polarization in traditional HE systems greatly restrains the increase in energy storage density. Herein, the contradiction is effectively solved by regulating the octahedral tilt and cationic displacement in ABO3-type perovskite HE ceramics, i.e., (1-x)[0.6(Bi0.47Na0.47Yb0.03Tm0.01)TiO3-0.4(Ba0.5Sr0.5)TiO3]-xSr(Zr0.5Hf0.5)O3 (BNYTT-BST-xSZH). Combining the tape-casting process and cold isostatic pressing, the optimal BNYTT-BST-0.06SZH ceramic displays a large recoverable energy storage density (10.46 J cm-3) at 685 kV cm-1 and a high PD (332.88 MW cm-3). More importantly, due to Tm/Yb codoping, abnormal fluorescent negative thermal expansion and excellent real-time temperature sensing are developed, thus the application of fault detection and warning in high-voltage transmission line systems is conceptualized. This study provides an effective strategy for enhancing the polarization of energy-storing HE ceramics and offers a promising material for overcoming the problems of insufficient capacitor density and thermal runaway in terminal communication.

Design and Manufacturing of Dielectric Resonators via 3D Printing of Composite Polymer/Ceramic Filaments.

Rapid technological advancements in recent years have opened the door to innovative solutions in the field of telecommunications and wireless systems; thus, new materials and manufacturing methods have been explored to satisfy this demand. This paper aims to explore the application of low-cost, commercially available 3D-printed ceramic/polymer composite filaments to design dielectric resonators (DRs) and check their suitability for use in high-frequency applications. Three-dimensional printing was used to fabricate the three-dimensional dielectric resonant prototypes. The filaments were characterized in terms of their thermal and mechanical properties and quality of printability. Additionally, the filaments' dielectric properties were analyzed, and the prototypes were designed and simulated for a target frequency of ~2.45 GHz. Afterward, the DRs were successfully manufactured using the 3D printing technique, and no post-processing techniques were used in this study. A simple and efficient feeding method was used to finalize the devices, while the printed DRs' reflection coefficient (S11) was measured. Results on prototype size, manufacture ease, printability, cost per volume, and bandwidth (BW) were used to evaluate the materials' suitability for high-frequency applications. This research presents an easy and low-cost manufacturing process for DRs, opening a wide range of new applications and revolutionizing the manufacturing of 3D-printed high-frequency devices.

Preparation and Photocatalytic Properties of Al2O3-SiO2-TiO2 Porous Composite Semiconductor Ceramics.

Titanium dioxide (TiO2) is widely employed in the catalytic degradation of wastewater, owing to its robust stability, superior photocatalytic efficiency, and cost-effectiveness. Nonetheless, isolating the fine particulate photocatalysts from the solution post-reaction poses a significant challenge in practical photocatalytic processes. Furthermore, these particles have a tendency to agglomerate into larger clusters, which diminishes their stability. To address this issue, the present study has developed Al2O3-SiO2-TiO2 composite semiconductor porous ceramics and has systematically explored the influence of Al2O3 and SiO2 on the structure and properties of TiO2 porous ceramics. The findings reveal that the incorporation of Al2O3 augments the open porosity of the ceramics and inhibits the aggregation of TiO2, thereby increasing the catalytic site and improving the light absorption capacity. On the other hand, the addition of SiO2 enhances the bending strength of the ceramics and inhibits the conversion of anatase to rutile, thereby further enhancing its photocatalytic activity. Consequently, at an optimal composition of 55 wt.% Al2O3, 40 wt.% TiO2, and 5 wt.% SiO2, the resulting porous ceramics exhibit a methylene blue removal rate of 91.50%, and even after undergoing five cycles of testing, their catalytic efficiency remains approximately 83.82%. These outcomes underscore the exceptional photocatalytic degradation efficiency, recyclability, and reusability of the Al2O3-SiO2-TiO2 porous ceramics, suggesting their substantial potential for application in the treatment of dye wastewater, especially for the removal of methylene blue.

Modulation of Free Carbon Structures in Polysiloxane-Derived Ceramics for Anode Materials in Lithium-Ion Batteries.

Polymer-derived silicon oxycarbide (SiOC) ceramics have garnered significant attention as novel silicon-based anode materials. However, the low conductivity of SiOC ceramics is a limiting factor, reducing both their rate capability and cycling stability. Therefore, controlling the free carbon content and its degree of graphitization within SiOC is crucial for determining battery performance. In this study, we regulated the free carbon content using divinylbenzene (DVB) and controlled the graphitization of free carbon with the transition metal iron (Fe). Through a simple pyrolysis process, we synthesized SiOC ceramic materials (CF) and investigated the impact of Fe-induced changes in the carbon phase and the amorphous SiOC phase on the comprehensive electrochemical performance. The results demonstrated that increasing the DVB content in the SiOC precursor enhanced the free carbon content, while the addition of Fe promoted the graphitization of free carbon and induced the formation of carbon nanotubes (CNTs). The electrochemical performance results showed that the CF electrode material exhibited a high reversible capacity of approximately 1154.05 mAh g-1 at a low current density of 100 mA g-1 and maintained good rate capability and cycling stability after 1000 cycles at a high current density of 2000 mA g-1.

Ceramic substitutes, failure to achieve solid fusion in posterolateral instrumented fusion: a surgical and histological evaluation.

PURPOSE: As the number of instrumented fusions increases, so does the utilization of bone substitutes. However, controversies persist regarding the effectiveness of ceramics in promoting solid fusion. Few histological studies have been conducted on patients to address this issue. To contribute insights into this topic, we assessed bony fusion both intraoperatively and histologically in patients who underwent posterolateral instrumented fusions enhanced with a biphasic ceramic compound. METHODS: We analyzed a series of 13 patients who underwent revision surgery due to adjacent segment disease following the initial use of ceramics as bone extenders in the index surgery. In each case, patients exhibited apparent radiological fusion in the instrumented posterolateral fusions. Follow-up exceeded 18 months. Bone fusion was assessed intraoperatively, and biopsies of the bone mass at the intertransverse area were examined under an optical microscope. RESULTS: Surgical exploration of the fusion block at the intertransverse space did not indicate solid fusion. Moreover, histological analysis of the 13 biopsies revealed a lack of proper integration of the bone substitutes, incomplete resorption of hydroxyapatite granules, and substitution of ceramic particles by immature fibrous tissue lacking the structural competence to bear loads or add stability to spinal fusion. CONCLUSION: The utilization of biphasic ceramics proved ineffective in attaining a proper fusion mass between the intertransverse space. Both surgical inspection and histological studies confirmed the absence of integration. Prudence should be exercised regarding the use of ceramics. While no clear instability was observed, neither was there any integration.

Assessment of the physiochemical properties and sustainability of locally produced ceramic G-filter in a long term experiment.

In India, Ceramic Water Filters (CWF) named G-filters are becoming a point-of-use household water treatment solution. The filter's reliability may be primarily characterized by the filtrate turbidity and microbial removal efficiency. The temperature and moisture gradients of the location affect its performance. This paper describes a 19-week laboratory investigation of G-filters simulating field conditions. The basic objective during the study was to ascertain the effective useable life of the filter. The discharge rate and turbidity reduction ability of the filters are studied in depth. The G-filters were prepared using locally available salty clay and sawdust taken in equal volume fractions. A total of 30 filters with a 9-liter capacity each were used for the experiments. The results showed that CWFs can reduce turbidity effectively. The influent water used for the study had a mean turbidity of 7.65 NTU, which reduced in the range of 0.03 NTU to 1.03 NTU. Over the course of four months, the average flow rate decreased from 1.94 Lh-1 to 0.93 Lh-1. Although a soft brushing of filters improved the filtration rate but that too failed in the long run. Brunauer-Emmett-Teller (BET) nitrogen adsorption-desorption measurements were used to determine the variation in pore size of filters with time. An average pore radius of 2.91 nm was found in the original filter that has not been used for filtration experiments. Moreover, an average pore radius of 1.77 nm, 1.21 nm, and 1.22 nm were reported in G-filters through which 427.5 L, 807.5 L, and 1035.5 L, respectively, of water were passed. This reduction in pore size is attributed to the clogging of pores over a period of time. This study aims to collect performance data to establish a scientific model using statistical analysis for implementing CWF technology in developing nations.

In Vitro Effect of Anodization of Titanium Abutments on Color Parameters and Color Difference of Lithium Disilicate All-Ceramic Crowns.

OBJECTIVE: This study assessed the effect of the anodization of titanium abutments on the color parameters and color difference of lithium disilicate (LDS) all-ceramic crowns. MATERIALS AND METHODS: In this study, 19 straight abutments were divided into two groups: anodized (n = 9) and non-anodized control (n = 9), with one hybrid zirconia abutment as a reference. Anodization was achieved by applying 63 V energy using seven 9 V flat batteries in series, with an electrolyte solution comprising 1 g trisodium phosphate in 250 mL distilled water for 5 s, resulting in a gold-yellow color. Abutments were then scanned, and full-contour monolithic IPS e.max maxillary central incisor crowns were fabricated with 2 mm thickness and glazed. Reflectance was measured using a spectroradiometer, and color coordinates (L*, a*, b*, h*, and C*) were calculated using CS-10W software. Color differences of the crowns in both groups were quantified using the CIEDE2000 (ΔE00) color difference formula and analyzed by t-test (α = 0.05) compared to the standard sample. RESULTS: The L*, a*, b*, and c* parameters in anodized abutments were significantly higher than those in non-anodized abutments, while the h* parameter in anodized abutments was significantly lower than that in non-anodized abutments (p < 0.001 for all). There was a significant difference in ΔE00 of the two groups (p = 0.043). CONCLUSION: Anodization of titanium abutments improved the color parameters of LDS all-ceramic crowns and significantly decreased their ΔE compared with non-anodized abutments.

Influence of microstructure on optical properties of CAD-CAM lithium disilicate glass-ceramics.

OBJECTIVES: To evaluate the influence of microstructure and chemical composition on the optical properties of CAD-CAM lithium disilicate glass-ceramics. METHODS: Samples (n = 5; 1.0 mm thickness) of shades A1, A2, and A3 were fabricated from CAD-CAM ceramic blocks (Ivoclar Vivadent): IPS e.max® CAD LT (emLT) and HT (emHT). Samples were polished to 1.0 ± 0.01 mm in thickness. The optical properties (R- reflectance; T- transmittance; µs'- reduced scattering and µa- absorption coefficients) from the post-crystallized samples were determined using the inverse adding-doubling (IAD) method based on integrating-sphere measurements. Additionally, scanning electron microscopy (SEM) and X-ray diffraction (XRD) techniques were used to evaluate the microstructural properties. Energy-dispersive X-ray (EDX) was employed to analyze the chemical composition. The chemical and structural characterization were performed before and after crystallization of the ceramic samples. RESULTS: emLT showed higher values of µs'and lower values of µa and T than emHT for each shade in all wavelengths (p < 0.003). Considering T for emHT, there were no statistical differences for shades A1 and A2 at 488 nm and 514.5 nm (p > 0.003) and shades A1 and A3 at 457.9 nm (p > 0.003). emLT showed particle length ranging from 0.74 to 2.78 µm (mean = 1.57 µm and RF-relative frequency = 28 %) and particle width ranging from 0.21 to 0.74 µm (mean = 0.30 µm and RF = 31 %). emHT showed particle length ranging from 0.83 to 3.08 µm (mean = 1.86 µm and RF = 21 %) and particle width ranging from 0.24 to 1.12 µm (mean = 0.56 µm and RF = 28 %). In comparison with emHT, emLT showed greater vol% for C, K, and Zr and lower vol% for O and Al. SIGNIFICANCE: The optical properties of CAD-CAM lithium disilicate glass-ceramics are influenced by the chemical composition and, consequently, by the material microstructure.

Does the surface conditioning of glass and hybrid ceramics with self-etching silane present a bond strength similar to that of conventional bonding? Systematic review and meta-analysis of in vitro studies.

PURPOSE: To evaluate, through in vitro studies, the bond strength of vitreous and hybrid ceramics with self-etching surface treatment compared to conventional treatment. METHODS: This systematic review followed the preferred reporting items for systematic reviews and meta-analyses (PRISMA) and was registered on the open science framework (OSF) platform for in vitro studies. A population, intervention, control, and outcome (PICO) question was formulated: "Does the surface conditioning of glass and hybrid ceramics with self-etching silane present a bond strength similar to that of conventional bonding?". A literature search was carried out in the PubMed, Embase, Web of Science, Cochrane Library, and ProQuest databases until September 2023. The Joanna Briggs Institute (JBI) critical appraisal guidelines for quasi-experimental studies were used for risk assessment of bias. The meta-analysis was based on the inverse variance (IV) method (p < 0.05). RESULTS: A total of 29 in vitro studies published between 2017 and 2022 were included in this systematic review, totaling 1889 ceramic samples. The meta-analysis indicated a significant decrease in the bond strength of HF 4%-5% with silane compared to self-etching (p < 0.05; MD: 0.34; 95% CI: 0.13-0.35; I2 = 3%, p = 0.42), while it indicated that there was no significant difference between self-etching compared to 9%-10% HF with silane (p = 0.92; MD: 0.02; 95% CI: -0.32 to 0.36; I2 = 14%, p = 0.32). CONCLUSION: Self-etching primer presents bond strength that is superior to or similar to conventional surface treatment on glass and hybrid ceramics.

Optical properties of advanced lithium disilicate.

BACKGROUND: A variety of firing protocols are available for the IPS e.max lithium disilicate (LD) and can be used for new, 'advanced' LD (ALD). However, the impact of firing protocols on the optical properties of ALD is still unknown. OBJECTIVES: The aim of the present study was to evaluate the color difference (ΔE00), the translucency parameter (TP00) and the whiteness index for dentistry (WID) for both LD glass ceramics after the processes of firing/glazing. MATERIAL AND METHODS: Fifty disk-shaped specimens, with a diameter of 10 mm and a thickness of 1.2 mm, were fabricated from IPS e.max CAD (LD; Ivoclar) and another 50 from CEREC Tessera™ (ALD; Dentsply Sirona). The specimens from each group were further divided into 5 subgroups (n = 10) according to the firing/glazing protocol applied: crystallization (c); one-step crystallization and glazing (cg); crystallization and refiring (c-r); two-step crystallization and glazing (c-g); or long-firing crystallization (lfc). The ΔE00, TP00 and WID were assessed. The statistical analysis of ΔE00 was performed using the one-way analysis of variance (ANOVA) and Tukey's post hoc test, while TP00 and WID were analyzed with the two-way ANOVA and Tukey's post hoc test at a statistical significance level of 0.05. The cg groups were designated as the reference. RESULTS: The ANOVA showed that the firing procedures had no effect on ΔE00, TP00 and WID in the case of LD. In addition, LD exhibited greater translucency and brightness as compared to ALD. For ALD, all color changes observed in relation to the reference firing protocol were clinically unacceptable. The ALD specimens which underwent 1 standard firing cycle showed higher TP00 and WID values than other ALD groups. CONCLUSIONS: The choice of the firing protocol has no impact on the color, TP00 or WID of LD. Additionally, LD presents higher WID values than ALD, irrespective of the firing protocol used. Alternative firing protocols result in clinically unacceptable color variations when compared to the manufacturer-recommended protocol for ALD. Advanced LD is more sensitive to different firing protocols with regard to its optical properties, which makes the workflow less predictable in comparison with LD.