Direct Visualization of Chemical Transport in Solid-State Chemical Reactions by Time-of-Flight Secondary Ion Mass Spectrometry.

Systematic control and design of solid-state chemical reactions are required for modifying materials properties and in novel synthesis. Understanding chemical dynamics at the nanoscale is therefore essential to revealing the key reactive pathways. Herein, we combine focused ion beam-scanning electron microscopy (FIB-SEM) and time-of-flight secondary ion mass spectrometry (TOF-SIMS) to track the migration of sodium from a borate coating to the oxide scale during in situ hot corrosion testing. We map the changing distribution of chemical elements and compounds from 50 to 850 °C to reveal how sodium diffusion induces corrosion. The results are validated by in situ X-ray diffraction and post-mortem TOF-SIMS. We additionally retrieve the through-solid sodium diffusion rate by fitting measurements to a Fickian diffusion model. This study presents a step change in analyzing microscopic diffusion mechanics with high chemical sensitivity and selectivity, a widespread analytical challenge that underpins the defining rates and mechanisms of solid-state reactions.

A model approach to show that monocytes can enter microporous ß-TCP ceramics.

ß-TCP ceramics are versatile bone substitute materials and show many interactions with cells of the monocyte-macrophage-lineage. The possibility of monocytes entering microporous ß-TCP ceramics has however not yet been researched. In this study, we used a model approach to investigate whether monocytes might enter ß-TCP, providing a possible explanation for the origin of CD68-positive osteoclast-like giant cells found in earlier works.We used flow chambers to unidirectionally load BC, PRP, or PPP into slice models of either 2 mm or 6 mm ß-TCP. Immunofluorescence for CD68 and live/dead staining was performed after the loading process.Our results show that monocytes were present in a relevant number of PRP and BC slices representing the inside of our 2 mm slice model and also present on the actual inside of our 6 mm model. For PPP, monocytes were not found beyond the surface in either model.Our results indicate the possibility of a new and so far neglected constituent in ß-TCP degradation, perhaps causing the process of ceramic degradation also starting from inside the ceramics as opposed to the current understanding. We also demonstrated flow chambers as a possible new in vitro model for interactions between blood and ß-TCP.

Facile Deficiency Engineering in a Cobalt-Free Perovskite Air Electrode to Achieve Enhanced Performance for Protonic Ceramic Fuel Cells.

As a crucial component responsible for the oxygen reduction reaction (ORR), cobalt-rich perovskite-type cathode materials have been extensively investigated in protonic ceramic fuel cell (PCFC). However, their widespread application at a commercial scale is considerably hindered by the high cost and inadequate stability. In response to these weaknesses, the study presents a novel cobalt-free perovskite oxide, Ba0.95La0.05(Fe0.8Zn0.2)0.95O3-δ (BLFZ0.95), with the triple-conducting (H+|O2-|e-) property as an active and robust air electrode for PCFC. The B-site deficiency state contributes significantly to the optimization of crystal and electronic structure, as well as the increase in oxygen vacancy concentration, thus in turn favoring the catalytic capacity. As a result, the as-obtained BLFZ0.95 electrode demonstrates exceptional electrochemical performance at 700 °C, representing extremely low area-specific resistance of 0.04 Ω cm2 in humid air (3 vol.% H2O), extraordinarily high peak power density of 1114 mW cm-2, and improved resistance against CO2 poisoning. Furthermore, the outstanding long-term durability is achieved without visible deterioration in both symmetrical and single cell modes. This study presents a simple but crucial case for rational design of cobalt-free perovskite cathode materials with appreciable performance via B-site deficiency regulation.

Influence of Oxygen Vacancies Introduced via Acceptor (Gadolinium) Doping to the Pseudocapacitive Properties of Nano-Sized Cerium Oxide.

The voluntary introduction of defects can be considered an effective strategy for enhancing the electrochemical properties of metal oxide electrodes. In this study, the enhanced pseudocapacitive properties of an acceptor (Gd) doped cerium oxide nanoparticle-a sustainable metal oxide with low environmental and human toxicity-are investigated in depth using ex situ X-ray photoemission spectroscopy (XPS) and electrochemical impedance spectroscopy (EIS). Interestingly, with 15 at% Gd doping (15GDC), the specific capacitance of the nanoparticles measured at 1 A g-1 enhanced to 547.8 F g-1, which is fivefold higher than undoped CeO2 (98.7 F g-1 at 1 A g-1). The rate-dependent capacitance is also improved for 15GDC, which showed a 31.0% decrease in the specific capacitance upon a tenfold increase in the current density, while CeO2 showed a 49.9% decrease. The enhanced electrochemical properties are studied in depth via ex situ XPS and EIS analysis, which revealed that the oxygen vacancies at the surface of the nanoparticles played important roles in enhancing both the specific capacitance and the high-rate performance of 15GDC by acting as the active site for pseudocapacitive redox reaction and allowing fast diffusion of oxygen ions at the surface of 15GDC nanoparticles.

Fully Printed Multilayer Ceramic Capacitors Based on High-k Perovskite Nanosheets.

Printing technology enables the integration of chemically exfoliated perovskite nanosheets into high-performance microcapacitors. Theoretically, the capacitance value can be further enhanced by designing and constructing multilayer structures without increasing the device size. Yet, issues such as interlayer penetration in multilayer heterojunctions constructed using inkjet printing technology further limit the realization of this potential. Herein, a series of multilayer configurations, including Ag/(Ca2NaNb4O13/Ag)n and graphene/(Ca2NaNb4O13/graphene)n (n = 1-3), are successfully inkjet-printed onto diverse rigid and flexible substrates through optimized ink formulations, inkjet printing parameters, thermal treatment conditions, and rational multilayer structural design using high-k perovskite nanosheets, graphene nanosheets and silver. The dielectric performance is optimized by fine-tuning the number of dielectric layers and modifying the electrode/dielectric interface. As a result, the graphene/(Ca2NaNb4O13/graphene)3 multilayer ceramic capacitors exhibit a remarkable capacitance density of 346 ± 12 nF cm-2 and a high dielectric constant of 193 ± 18. Additionally, these devices demonstrate moderate insulation properties, flexibility, thermal stability, and chemical sensitivity. This work shed light on the potential of multilayer structural design in additive manufacturing of high-performance 2D material-based ceramic capacitors.

Strong and Robust Core-Shell Ceramic Fibers Composed of Highly Compacted Nanoparticles for Multifunctional Electronic Skin.

Functional fibers composed of textiles are considered a promising platform for constructing electronic skin (e-skin). However, developing robust electronic fibers with integrated multiple functions remains a formidable task especially when a complex service environment is concerned. In this work, a continuous and controllable strategy is demonstrated to prepare e-skin-oriented ceramic fibers via coaxial wet spinning followed by cold isostatic pressing. The resulting core-shell structured fiber with tightly compacted Al-doped ZnO nanoparticles in the core and highly ordered aramid nanofibers in the shell exhibit excellent tensile strength (316 MPa) with ultra-high elongation (33%). Benefiting from the susceptible contacts between conducting ceramic nanoparticles, the ceramic fiber shows both ultrahigh sensitivity (gauge factor = 2141) as a strain sensor and a broad working range up to 70 °C as a temperature sensor. Furthermore, the tunable core-shell structure of the fiber enables the optimization of impedance matching and attenuation of electromagnetic waves for the corresponding textile, resulting in a minimum reflection loss of -39.1 dB and an effective absorption bandwidth covering the whole X-band. Therefore, the versatile core-shell ceramic fiber-derived textile can serve as a stealth e-skin for monitoring the motion and temperature of robots under harsh conditions.

Investigation of Water Impacts on Surface Properties and Performance of Air-Electrode in Reversible Protonic Ceramic Cells.

Water, being abundant and readily accessible, gains widespread usage as proton source in many catalysis and energy conversion technologies, including applications like reversible protonic ceramic cells (R-PCCs). Revealing the influence of water on the electrode surface and reaction kinetics is critical for further improving their electrochemical performance. Herein, a hydrophilic air-electrode PrBa0.875Cs0.125Co2O5+δ is developed for R-PCC, which demonstrates a remarkable peak power density of 1058 mW cm-2 in fuel cell mode and a current density of 1354 mA cm-2 under 1.3 V in electrolyzing steam at 650 °C. For the first time on R-PCC, surface protons' behavior in response to external voltages is captured using in situ FTIR characterizations. Further, it is shown that contrary to the bulk proton uptake process that is thought to follow hydrogenation reactions and lead to cation reductions. The air-electrode presents enriched surface protons occurring through oxidizing surface cations, as confirmed by depth-profiling XPS results. H/D isotope exchange experiments and subsequent electrochemical characterization analyses reveal that the presence of protons enhances surface reactions. This study fills the knowledge gap between water-containing atmospheres and electrochemical performance by providing insights into the surface properties of the material. These new findings provide guidance for future electrode design and optimization.

Heat-Localized and Salt-Resistant 3D Hierarchical Porous Ceramic Platform for Efficient Solar-Driven Interfacial Evaporation.

Solar-driven interfacial evaporation (SDIE) is a highly promising approach to achieve sustainable desalination and tackle the global freshwater crisis. Despite advancements in this field, achieving balanced thermal localization and salt resistance remains a challenge. Herein, the study presents a 3D hierarchical porous ceramic platform for SDIE applications. The utilized alumina foam ceramics (AFCs) exhibit remarkable corrosion resistance and chemical stability, ensuring a prolonged operational lifespan in seawater or brines. The millimeter-scale air-filled pores in AFCs prevent thermal losses through conduction with bulk water, resulting in heat-localized interfaces. The hydrophilic nature of macroporous AFC skeletons facilitates rapid water replenishment on the evaporating surface for effective salt-resistant desalination. Benefiting from its self-radiation adsorption and side-assisted evaporation capabilities, the AFC-based evaporators exhibit high indoor evaporation rates of 2.99 and 3.54 kg m-2 h-1 under one-sided and three-sided illumination under 1.0 sun, respectively. The AFC-based evaporator maintains a high evaporation rate of ≈2.77 kg m-2 h-1 throughout the 21-day long-term test. Furthermore, it achieves a daily water productivity of ≈10.44 kg m-2 in outdoor operations. This work demonstrates the potential of 3D hierarchical porous ceramics in addressing the trade-off between heat localization and salt resistance, and contributes to the development of durable solar steam generators.

Modulating Lattice Oxygen Activity of Iron-Based Triple-Conducting Nanoheterostructure Air Electrode via Sc-Substitution Strategy for Protonic Ceramic Cells.

Iron-based perovskite air electrodes for protonic ceramic cells (PCCs) offer broad application prospects owing to their reasonable thermomechanical compatibility and steam tolerance. However, their insufficient electrocatalytic activity has considerably limited further development. Herein, oxygen-vacancy-rich BaFe0.6 Ce0.2 Sc0.2 O3-δ (BFCS) perovskite is rationally designed by a facile Sc-substitution strategy for BaFe0.6 Ce0.4 O3-δ (BFC) as efficient and stable air electrode for PCCs. The BFCS electrode with an optimized Fe 3d-eg orbital occupancy and more oxygen vacancies exhibits a polarization resistance of ≈ 0.175 Ω cm2 at 600 °C, ≈ 1/3 of the BFC electrode (≈0.64 Ω cm2 ). Simultaneously, BFCS shows favorable proton uptake with a low proton defect formation enthalpy (- 81 kJ mol-1 ). By combining soft X-ray absorption spectroscopy and electrical conductivity relaxation studies, it is revealed that the enhancement of Fe4+ -O2- interactions in BFCS promotes the activation and mobility of lattice oxygen, triggering the activity of BFCS in both oxygen reduction and evolution reactions (ORR/OER). The single cell achieves encouraging output performance in both fuel cell (1.55 W cm-2 ) and electrolysis cell (-2.96 A cm-2 at 1.3 V) modes at 700 °C. These results highlight the importance of activating lattice oxygen in air electrodes of PCCs.

Enhancing mechanical properties of composite solid electrolyte by ultra-high molecular weight polymers.

Composite solid electrolytes combining the advantages of inorganic and polymer electrolytes are considered as one of the promising candidates for solid-state lithium metal batteries. Compared with ceramic-in-polymer electrolyte, polymer-in-ceramic electrolyte displays excellent mechanical strength to inhibit lithium dendrite. However, polymer-in-ceramic electrolyte faces the challenges of lack of flexibility and severely blocked Li+transport. In this study, we prepared polymer-in-ceramic film utilizing ultra-high molecular weight polymers and ceramic particles to combine flexibility and mechanical strength. Meanwhile, the ionic conductivity of polymer-in-ceramic electrolytes was improved by adding excess lithium salt in polymer matrix to form polymer-in-salt structure. The obtained film shows high stiffness (10.5 MPa), acceptable ionic conductivity (0.18 mS cm-1) and high flexibility. As a result, the corresponding lithium symmetric cell stably cycles over 800 h and the corresponding LiFePO4cell provides a discharge capacity of 147.7 mAh g-1at 0.1 C without obvious capacity decay after 145 cycles.

Toward High-Performance Piezoresistive Polymer Derived SiOC Ceramics through Masked Stereolithography 3D Printing with ß-Silicon Carbide Nanopowder Reinforcement.

Enhancing the piezoresistivity of polymer-derived silicon oxycarbide ceramics (SiOCPDC ) is of great interest in the advancement of highly sensitive pressure/load sensor technology for use in harsh and extreme working conditions. However, a facile, low cost, and scalable approach to fabricate highly piezoresistive SiOCPDC below 1400 °C still remains a great challenge. Here, the fabrication and enhancement of piezoresistive properties of SiOCPDC reinforced with ß-SiC nanopowders (SiCNP ) through masked stereolithography-based 3D-printing and subsequent pyrolysis at 1100 °C are demonstrated. The presence of free carbon in SiCNP augments high piezoresistivity in the fabricated SiCNP -SiOCPDC composites even at lower pyrolysis temperatures. A gauge factor (GF) in the range of 4385-5630 and 6129-8987 with 0.25 and 0.50 wt% of SiCNP , respectively is demonstrated, for an applied pressure range of 0.5-5 MPa at ambient working conditions. The reported GF is significantly higher compared to those of any existing SiOCPDC materials. This rapid and facile fabrication route with significantly enhanced piezoresistive properties makes the 3D-printed SiCNP -SiOCPDC composite a promising high-performance material for the detection of pressure/load in demanding applications. Also, the overall robustness in mechanical properties and load-bearing capability ensures its long-term stability and makes it suitable for challenging and severe environment applications.

Adsorption-coupled Fenton type reduction of bromate in water by high-yield polymer-derived ceramic-supported nano-zerovalent iron.

Nano-zerovalent iron (nZVI) is a promising material for the removal of both organic and inorganic pollutants from contaminated water. This study investigates the potential of a novel composite of nZVI on a polymer-derived supporting ceramic (nZVI-PDC) synthesized via the liquid-phase reduction method for the simultaneous adsorption and Fenton-type reduction of bromate anion (BrO3-) in water. The nZVI nanoparticles were effectively anchored onto the PDC by impregnating high-yield carbon in a ferrous sulfate solution. The PDC facilitated the uniform dispersion of nZVI nanoparticles due to its multiple active sites distributed within mesocarbon cavities. The developed nZVI-PDC composite exhibited a high specific surface area of 837 m2 g-1 and an ordered mesoporous structure with a pore volume of 0.37 cm3 g-1. As an adsorbent, the nZVI-PDC composite exhibited a maximum adsorption capacity (qe) of 842 mg g-1 and a partition coefficient (KH) of 10.2 mg g-1 µM-1, as calculated by the pseudo-second-order model. As a catalyst, the composite demonstrated a reaction kinetic rate of 43.5 µmol g-1 h-1 within 6 h at pH 4, using a dosage of 60 mg L-1 nZVI-PDC and a concentration of 0.8 mmol L-1 H2O2. Comparatively, PDC exhibited a qe of 408 mg g-1, KH of 1.67 mg g-1 µM-1, and a reaction rate of 20.8 µmol g-1 h-1, while nZVI showed a qe of 456 mg g-1, KH of 2.30 mg g-1 µM-1, and a reaction rate of 27.2 µmol g-1 h-1. The modelling indicated that the nZVI-PDC composite followed pseudo-second-order kinetics. The remarkable removal efficiency of the nZVI-PDC composite was attributed to the synergistic effects between PDC and nZVI, where PDC facilitated charge transfer, promoting Fe2+ generation and the Fe3+/Fe2+ cycle. Overall, this work introduces a promising adsorption technology for the efficient removal of BrO3- from contaminated aqueous solutions, highlighting the significant potential of the nZVI-PDC composite in water purification applications.

Clinical performance and risk factors of all-ceramic screw-retained implant crowns in the posterior region based on a retrospective investigation.

OBJECTIVES: Clinical data on all-ceramic screw-retained implant crowns (SICs) luted on titanium base abutments (TBAs) over more than 3 years are sparse. This study aimed to evaluate the clinical performance and potential risk factors for these restorations. MATERIALS AND METHODS: Analysis took place based on the medical patient-records of three dental offices. Implant survival and prosthetic complications over time were evaluated. The study included SICs in premolar and molar regions made from monolithic lithium disilicate ceramic (M_LiDi) or veneered zirconia (V_ZiO) luted on a TBA documented over an observation time of at least 3 years. Survival and complication rates were calculated and compared by a log-rank test. Cox-Regressions were used to check potential predictors for the survival (p < .05). RESULTS: Six hundred and one crowns out of 371 patients met the inclusion criteria and follow-up period was between 3.0 and 12.9 (mean: 6.4 (SD: 2.1)) years. Over time, six implants had to be removed and 16 restorations had to be refabricated. The estimated survival rates over 10 years were 93.5% for M_LiDi and 95.9% for V_ZiO and did not differ significantly among each other (p = .80). However, V_ZiO showed significantly higher complication rates (p = .003). Material selection, sex, age, and implant diameter did not affect the survival of investigated SICs but crown height influences significantly the survival rate (hazard ratio, HR = 1.26 (95%CI: 1.08, 1.49); p = .043). CONCLUSIONS: Screw-retained SICs luted on TBAs that were fabricated from monolithic lithium disilicate ceramic or veneered zirconia showed reliable and similar survival rates. Increasing crown heights reduced survival over the years.

Evaluation of bond strength between zirconia milled ceramic material and veneered dental porcelain.

This study aimed at examining the bond strength between zirconia and ceramic veneer, following the ISO 9693 guidelines. A total of fifty specimens of zirconia/ceramic-veneer system were produced using two commercial zirconias (VITA YZ-HTWhite and Zolid HT+ White, referred to as Group A and Group B, respectively) and a ceramic-veneering material (Zirkonia 750). The microstructure (via x-ray diffraction analysis, XRD and Secondary Electron mode, SEM) and the mechanical properties (via 3-point bending tests) of the two groups were assessed. Then, experiments were conducted according to the ISO 9693 and conventional protocols applied for producing zirconia/ceramic-veneer restorations. Bond strength values, measured by 3-point bending tests, were 34.42 ± 7.60 MPa for Group A and 31.92 ± 6.95 MPa for Group B. SEM observations of the cohesively fractured surfaces (on the porcelain side) and the examination for normality using the Shapiro-Wilk test suggested the use of Weibull statistical analysis. Median strength (σ50%) for Group A and Group B was 34.76 and 32.22 MPa, while the characteristic strength (σ63.2%) was 35.78 and 33.14 MPa, respectively. The Weibull modulus disparity between groups (12.69 and 13.07) was not significant. Bond strength exceeded the ISO 9693 minimum of 20 MPa, suggesting satisfactory strength for clinical use.

Direct Observation of Trace Elements in Barium Titanate of Multilayer Ceramic Capacitors Using Atom Probe Tomography.

Accurately controlling trace additives in dielectric barium titanate (BaTiO3) layers is important for optimizing the performance of multilayer ceramic capacitors (MLCCs). However, characterizing the spatial distribution and local concentration of the additives, which strongly influence the MLCC performance, poses a significant challenge. Atom probe tomography (APT) is an ideal technique for obtaining this information, but the extremely low electrical conductivity and piezoelectricity of BaTiO3 render its analysis with existing sample preparation approaches difficult. In this study, we developed a new APT sample preparation method involving W coating and heat treatment to investigate the trace additives in the BaTiO3 layer of MLCCs. This method enables determination of the local concentration and distribution of all trace elements in the BaTiO3 layer, including additives and undesired impurities. The developed method is expected to pave the way for the further optimization and advancement of MLCC technology.

Cryogen-free 400-MHz nuclear magnetic resonance spectrometer as a versatile tool for pharmaceutical process analytical technology.

The discovery of new ceramic materials containing Ba-La-Cu oxides in 1986 that exhibited superconducting properties at high temperatures in the range of 35 K or higher, recognized with the Nobel Prize in Physics in 1987, opened a new world of opportunities for nuclear magnetic resonance (NMRs) and magnetic resonance imaging (MRIs) to move away from liquid cryogens. This discovery expands the application of high temperature superconducting (HTS) materials to fields beyond the chemical and medical industries, including electrical power grids, energy, and aerospace. The prototype 400-MHz cryofree HTS NMR spectrometer installed at Amgen's chemistry laboratory has been vital for a variety of applications such as structure analysis, reaction monitoring, and CASE-3D studies with RDCs. The spectrometer has been integrated with Amgen's chemistry and analytical workflows, providing pipeline project support in tandem with other Kinetic Analysis Platform technologies. The 400-MHz cryofree HTS NMR spectrometer, as the name implies, does not require liquid cryogens refills and has smaller footprint that facilitates installation into a chemistry laboratory fume hood, sharing the hood with a process chemistry reactor. Our evaluation of its performance for structural analysis with CASE-3D protocol and for reaction monitoring of Amgen's pipeline chemistry was successful. We envision that the HTS magnets would become part of the standard NMR and MRI spectrometers in the future. We believe that while the technology is being developed, there is room for all magnet options, including HTS, low temperature superconducting (LTS) magnets, and low field benchtop NMRs with permanent magnets, where utilization will be dependent on application type and costs.

Performance of two laser motion modes versus conventional orthodontic ceramic brackets debonding technique on enamel surface topography.

The risk of enamel deterioration that frequently coexists with debonding of orthodontic teeth brackets elevates the mandate for finding an optimum approach for debonding them without harmful effects. This in-vitro study is intended to compare the effects of two different laser modes (scanning and circular) and a conventional method on the enamel surface after debonding orthodontic brackets. 66 extracted premolars were assigned into 3 groups. After that, light-cure composite resin was used to attach the ceramic brackets to the teeth. Amongst the test groups, Group I: specimens that were debonded using conventional debonding using pliers; Group 2: specimens that were debonded using Er, Cr: YSGG laser applications using the circular motion method; and Group 3: specimens that were debonded using Er, Cr: YSGG laser applications using the scanning motion method. Adhesive Remnant Index (ARI) assessment, intra-pulpal temperature increase, enamel surface roughness after polishing, and assessment of the microstructure of enamel were carried out with scanning electron microscopy. The gathered information was examined statistically. The conventional debonding method had a significantly higher proportion of adhesive remnant index (ARI) scores of 2 and 3 in comparison to the circular (p < .004) and scanning laser groups (p < .001). There was no significant difference in ARI scores between the circular and scanning laser groups (p > .05). Moreover, the circular and scanning laser debonding methods resulted in a significantly higher proportion of Enamel Surface Roughness (ESR) scores of 0 and a lower proportion of ESR scores of 3 compared to the conventional technique group (p < .001). However, there was no significant difference in ESR scores between the circular and scanning laser methods (p = .945). Lastly, the average intra-pulpal temperature was significantly higher in the circular laser group (1.9 ± 0.5 ) compared to the scanning laser group (0.9 ± 0.2) with p < .001. Er, Cr: YSGG laser irradiation is a tool that shows promise for debonding ceramic brackets with minimal harm to the enamel surface. The scanning laser technique is more desirable due to the lower intra-pulpal temperature increase.

Clinical and radiographic outcomes of a two-piece ceramic implant: one year results from a prospective clinical trial.

OBJECTIVE: To describe the clinical and radiographic performance and survival rate of a new two-piece ceramic implant system after at least 12 months of follow-up. MATERIALS AND METHODS: Sixty-five implants were placed and followed up for at least 12 months (12.3 ± 1.5), in 50 patients. The implants were installed both in fresh extraction sockets and in healed sites and received provisional restoration when the clinical insertion torque was greater than 35Ncm. The primary results describe the survival rate of these implants. Clinical performance was evaluated through the evaluation of the Pink Esthetic Score (PES) and the degree of satisfaction of the patients. Bone loss was measured through radiographic measurements of the marginal bone loss in the mesial (MBLM) and distal (MBLD) sites. RESULTS: The survival rate was 98.5%. The average MBLM was 0.24 mm (± 0.53) and the MBLD was 0.27 mm (± 0.57). A statistical difference was observed only when comparing immediate implants with delayed ones (MBLM - p = 0.046 and MBLD - p = 0.028) and when they received immediate provisionalization or not (MBLM - p = 0.009 and MBLD - p = 0.040). The PES before the intervention (T0) was 13.4 (± 0.8) and the PES at T2 (12-month follow-up) was 12.9 (± 1.5) (p = 1.14). CONCLUSION: The new two-piece ceramic implant used in the present study showed predictable and reliable results, similar to those found with titanium implants after one year of follow-up. CLINICAL RELEVANCE: These implants can be used as an alternative to titanium implants in terms of the marginal bone loss and the degree of patient satisfaction.

Effect of the use of bromelain associated with bioactive glass-ceramic on dentin/adhesive interface.

OBJECTIVES: To evaluate the effect of bromelain associated with Biosilicate on the bond strength (BS) of a universal adhesive system to sound (SD) and caries-affected dentin (CAD), and on the proteolytic activity. MATERIALS AND METHODS: Cavities were prepared in 360 molars, half submitted to cariogenic challenge. Teeth were separated into groups (n=20): Control-No treatment; CHX-0.12% chlorhexidine; NaOCl-5% sodium hypochlorite; Br5%-5% bromelain; Br10%-10% bromelain; Bio-10% Biosilicate; NaOClBio-NaOCl+Bio; Br5%Bio-Br5%+Bio; Br10%Bio-Br10%+Bio. Following treatments, the adhesive system was applied, and cavities were restored. Samples were sectioned into sticks and stored at 37 °C for 24 h, 6 months, and 1 year. Microtensile BS (2-way ANOVA, Bonferroni's test, α=0.05), fracture patterns (SEM), and adhesive interfaces (TEM) were evaluated. Bacterial collagenase assay and in situ zymography were performed. RESULTS: In CAD, Br10% presented higher BS (p=0.0208) than Br5%Bio. Br5% presented higher BS (p=0.0033) after 6 months than after 24 h; and association of treatments, higher BS (p<0.05) after aging than after 24 h. Mixed fractures were the most prevalent. Association of treatments promoted a more uniform hybrid layer with embedded Bio particles. Experimental groups presented lower (p<0.0001) relative fluorescence units than Control. Bromelain, associated or not with Bio, showed collagenolytic degradation. CONCLUSIONS: Bromelain associated with Biosilicate did not affect the BS to SD. In CAD, Br5%Bio decreased immediate BS but had no long-term influence. This association decreased the proteolytic activity. CLINICAL RELEVANCE: Bromelain and Biosilicate may enhance the longevity of adhesive restorations by inhibiting endogenous proteases.

Long-term performance of ceramic in/-onlays vs. cast gold partial crowns - a retrospective clinical study.

OBJECTIVES: To assess the long-term clinical performance of ceramic in-/onlays (CIOs) and cast gold partial crowns (CGPCs) in posterior teeth in terms of success, survival, complications (biological, technical) and quality. MATERIAL AND METHODS: In a retrospective study, a total of 325 patients were recorded after up to 24.8 years (mean 13.9 ± 3.8 years) having (pre-)molars restored with CIO (Empress I, Ivoclar Vivadent, n = 161) and CGPC (Degunorm, DeguDent, n = 164) by supervised undergraduate students. A total of 296 restorations were assessed clinically and radiologically in healthy and endodontically treated teeth using modified United States Public Health Service (USPHS) criteria. Cumulative success and survival rates of the restorations were calculated using Kaplan-Meier estimates. Biological and technical complications were recorded. Status of oral health comprising caries risk and localized periodontitis were assessed. RESULTS: The cumulative success rates of CIOs were 92.1% and of CGPCs 84.2% after mean service times of 14.5 years. The annual failure rates of total service times were 0.5% in teeth restored with CIO (n = 155) and 0.7% in teeth restored with CGPC (n = 163). The cumulative survival rates of CIOs were 93.9% after a mean service time of 15.2 years and decreased to 91.7% after 23.5 years. The cumulative survival rates of CGPCs were 92.6% after a mean service time of 14.9 years and 91.8% after 23.5 years. Complications in CIOs (n = 149) were ceramic fracture (6.7%), secondary caries (4.7%), endodontic complication (2.7%) and tooth fracture (1.3%) compared to CGPCs (n = 147) with endodontic complication (8.8%), secondary caries (4.8%) and decementation (2.0%). Endodontically treated teeth restored with CIO or CGPC revealed significantly less often success compared with corresponding vital teeth (p = .02). CIOs and CGPCs revealed clinically and radiographically good and excellent qualities with 71.8% (107/149) and 68% (100/147) without any significant differences regarding type of restoration. CONCLUSIONS: Both CIOs and CGPCs achieved high survival rates up to 24.8 years when performed by supervised undergraduate students. The longevity of the restorations may benefit from the intraoral repair of accessible defects and, in case of pulp infection or necrosis, an adequate endodontic management. CLINICAL RELEVANCE: CIOs and CGPCs made by supervised undergraduate students are proper restoration types in posterior teeth in the long-term. An adequate preparation design, meticulous care in the inserting technique and constant biofilm removal due to proper oral hygiene combined with professional maintenance care are substantial. The clinical long-term performance was mostly limited by ceramic fractures in CIOs and endodontic complications in CGPCs.