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Abstract Low efficiency and spectral instability caused by the surface defects have been considerable issues for the mixed‐halogen blue emitting perovskite quantum dots light‐emitting diodes (PeQLEDs). Here, an in situ surface passivation to perovskite quantum dots (PeQDs) is realized by introducing the metal cations competitive lattice occupancy assisted with acid‐etching, in which the long‐chain, insulating and weakly bond surface ligands are removed by addition of octanoic acid (OTAC). Meanwhile, the dissolved A‐site cations (Na+) compete with the protonated oleyl amine and are subsequently anchored to the surface vacancies. The preadded lead bromide, acting as inorganic ligands, demonstrates strong bonding to the uncoordinated surface ions. The as‐synthesized PeQDs show the boosted photoluminescence quantum yield (PLQY) and superior stability with longer lifetime. As a result, the PeQLEDs (470 nm) based on the OTAC‐Na PeQDs exhibit an external quantum efficiency of 8.42% in the mixed halogen PeQDs (CsPb(BrxCl1−x)3). Moreover, the device exhibits superior spectra stability with negligible shift. Our competition mechanism in combination with in situ passivation strategy paves a new way for improving the performance of blue PeQLEDs.

Background: The aim of this study was threefold. Firstly, it aimed to introduce and detail a novel method for chemically etching the bases of stainless-steel orthodontic brackets. Secondly, the study sought to investigate the structural alterations within the brackets' microstructure following chemical etching compared to those with sandblasted bases, using electron microscopy analysis. Lastly, the study aimed to evaluate and compare the long-term durability and survivability of orthodontic brackets with chemically etched bases versus those with sandblasted bases, both bonded using the conventional acid etch technique with Transbond XT adhesive, over an 18-month follow-up period. Methods: The study was a randomized clinical control trial with triple blinding and split-mouth study design and consisted of two groups. The brackets in the sandblasted group were prepared by sandblasting the intaglio surface of the base of the bracket with 50 µm SiO2 particles. Hydrofluoric acid was used to roughen the base in the acid-etched group. The bases of the brackets were viewed under an electron microscope to analyze the topographical changes. Results: A total of 5,803 brackets (3,006 acid-etch, 2,797 sandblasted) in 310 patients were bonded, in a split-mouth design by the same operator. The patients were followed for 18 months. The failure rate of 2.59% and 2.7% was noted in an acid-etched and sandblasted group, respectively. There was a close approximation of curves in the Kaplan-Meier plot, and the survival distribution of the two groups in the log-rank (Mantel-Cox) test was insignificant; x2 = 0.062 (P value = 0.804). Conclusion: Acid etching if the bases of the brackets can be used as an alternative to sandblasting furthermore acid etching can be performed on the chair side. [ABSTRACT FROM AUTHOR]

Surface modifications for titanium, a material of choice for dental implants, can greatly alter the surface micro/nanotopography and composition of implants, leading to notable enhancements in their hydrophilicity, mechanical properties, osseointegration performance, and antibacterial performance, as well as their impacts on osteoblast activity and bone formation processes. This article aims to update titanium surface modification techniques for dental implants from the past to the present, along with their effects on osteoblasts and bone formation, by thoroughly summarizing findings from published studies. Peer-reviewed articles published in English consisting of in vitro, in vivo, and clinical studies on titanium dental implant surface treatments were searched in Google Scholar, PubMed/MEDLINE, ScienceDirect, and the Scopus databases from January 1983 to December 2023 and included in this review. The previous studies show that implant surface roughness, condition, and hydrophilicity are crucial for osteoblast adhesion and growth. While various techniques enhance osseointegration comparably, one of the most common approaches to accomplishing these properties is sandblasting large-grit acid etching surface treatment and coating with hydroxyapatite or chitosan. In conclusion, this review points out the efficacy of different subtraction and addition techniques in enhancing the surface properties of titanium dental implants, promoting favorable outcomes in terms of osteoblast activity and bone formation in various degrees. However, most existing studies predominantly compare treated and non-treated titanium, revealing a need for more comprehensive studies comparing the effects of various modification techniques. Moreover, further investigation of factors playing a role in the dynamic osseointegration process in addition to osteoblasts and their functions, as well as improved surface modification techniques for the treatment of compromised patients, is greatly required. [ABSTRACT FROM AUTHOR]

Introduction: The longevity of cement-retained implant-supported restorations depends upon a strong and durable bond at the metal/cement interface. Various forms of surface treatments of implant abutments have been shown to enhance the retention of cement-retained restorations. The present study was undertaken to comparatively evaluate the tensile bond strength of metal copings luted onto implant abutments subjected to different surface treatments and determine the most effective surface treatment for long-term retention. Materials and Methods: Forty acrylic blocks were prepared, each with an implant analogue placed vertically inside the block and straight abutments tightened optimally onto implant analogues. The samples were divided into four Groups (n = 10) according to surface treatment of implant abutments: Group A – no surface treatment, Group B – sandblasting, Group C – metal primer application and Group D – acid etching. Metal copings were luted onto implant abutments, and the tensile force necessary to debond each metal coping was measured using a universal testing machine. Data were summarised in Mean ± Standard deviation. Groups were compared by one factor analysis of variance (ANOVA) and significance of mean difference between the groups was done by Tukey's honestly significant difference post hoc test after ascertaining normality by Shapiro-Wilk's test and homogeneity of variance between groups by Levene's test. A two-tailed (α = 2) P < 0.05 was considered statistically significant. Results: The highest mean tensile bond strength was recorded for Group C (metal primer application), followed by Groups B, D and A, respectively. Conclusion: Amongst the surface treatments used in the study, metal primer application was found to be most effective in improving the retention of cement-retained prostheses. [ABSTRACT FROM AUTHOR]

Aim of the study: This study compered the effect of two different implant surface treatments (Direct laser metal forming and Acid etching) on implant stability in All-on-4 implant retained mandibular overdentures. Materials and methods: 14 male patients were selected to participate in this study. For each patient, four implants were inserted at the inter-foraminal region using the All-on-4 concept. Patients were randomly divided into two groups according to surface treatment of dental implants. Primary and secondary implant stability were measured and compared by resonance frequency analysis using the osstell device at the time of implant insertion, 3 months and 6 months after implant insertion.Results: Comparison was performed between the straight implants of both groups and revealed that implant stability of group I is significantly higher than group II after 3months and after 6 months, while revealed insignificant difference between them at the time of insertion. Comparison was performed between the angled implants of both groups and revealed that implant stability of group I is significantly higher than group II after 3months and after 6 months, while revealed insignificant difference between them in time of insertion.Conclusions: Direct Metal Laser Forming surface treatment increases the secondary stability of angled implants supporting All-On-4 temporary prosthesis.

Abstract Background Alumina particles from the grit blasting of Ti-alloy stems are suspected to contribute to aseptic loosening. An alumina-reduced stem surface was hypothesized to improve osseointegration and show comparable short-term outcomes to those of a standard stem. Methods In this prospective, double-blind, randomized trial, 26 standard (STD) and 27 experimental new technology (NT) stems were implanted. The latter were additionally treated by acid etching and ice blasting to remove alumina particles from the grit-blasting process. Follow-up occurred at 12 and 24 months. Bone mineral density (BMD) around the stem was measured by a dual-energy x-ray absorptiometry device (DEXA). Radiographs were reviewed for alterations. Clinical scoring comprised the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and the Harris Hip Score (HHS). Survival rates were calculated up to 50 months. Results Lower mean BMD and more severe cortical hypertrophies were found in the NT group. At 12 months, radiolucent lines were observed mostly in the metaphyseal zone for both groups, with a progression tendency in the NT group at 24 months. At 12 months, pain scores and the WOMAC total and physical activity scores were significantly lower in the NT group, without any differences thereafter. The number of NT stem revisions amounted to 6 (24%) and 11 (41%) at 24 and 50 months, respectively. Conclusion In the NT group, unexpected catastrophic failure rates of 41% caused by early aseptic loosening were noted within 50 months. Compared with the STD stems, NT stems lead to poor clinical and radiographic results. Level of evidence: II. Trial Registration: NCT05053048.

Introduction: The longevity of cement-retained implant-supported restorations depends upon a strong and durable bond at the metal/cement interface. Various forms of surface treatments of implant abutments have been shown to enhance the retention of cement-retained restorations. The present study was undertaken to comparatively evaluate the tensile bond strength of metal copings luted onto implant abutments subjected to different surface treatments and determine the most effective surface treatment for long-term retention. Materials and Methods: Forty acrylic blocks were prepared, each with an implant analogue placed vertically inside the block and straight abutments tightened optimally onto implant analogues. The samples were divided into four Groups (n = 10) according to surface treatment of implant abutments: Group A – no surface treatment, Group B – sandblasting, Group C – metal primer application and Group D – acid etching. Metal copings were luted onto implant abutments, and the tensile force necessary to debond each metal coping was measured using a universal testing machine. Data were summarised in Mean ± Standard deviation. Groups were compared by one factor analysis of variance (ANOVA) and significance of mean difference between the groups was done by Tukey's honestly significant difference post hoc test after ascertaining normality by Shapiro-Wilk's test and homogeneity of variance between groups by Levene's test. A two-tailed (α = 2) P < 0.05 was considered statistically significant. Results: The highest mean tensile bond strength was recorded for Group C (metal primer application), followed by Groups B, D and A, respectively. Conclusion: Amongst the surface treatments used in the study, metal primer application was found to be most effective in improving the retention of cement-retained prostheses.

Introduction: Polyetheretherketone, also known as PEEK, is a semicrystalline thermoplastic material with many advantages. Since its grey material, it has to veneering with composite resin to enhance its aesthetic appeal. Bonding PEEK and composite veneers poses challenges due to its inert surface. Aim: To assess and compare the Shear Bond Strength (SBS) between various polyetheretherketone materials and veneering composites following various surface treatments. Materials and Methods: The in-vitro study was conducted at KSR Dental College and Hospital in Tiruchengode, Tamil Nadu, India, over a period of three months from December 2022 to February 2023. A total of 108 PEEK discs were prepared for the study, divided into three groups: unfilled PEEK, 30% carbon reinforced PEEK, and 10% carbon + 10% graphite + 10% Polytetrafluoroethylene (PTFE) reinforced PEEK. The specimens underwent different surface treatments, including no treatment, sandblasting with 110 um alumina particles, and acid etching with 98% sulphuric acid. Additionally, 108 composite discs were prepared and bonded to the PEEK specimens using adhesive and resin cement. The bonded specimens were immersed in distilled water for 24 hours, and the Shear Bond Strength (SBS) was determined using a universal testing machine. Statistical analysis was performed using one-way ANOVA, and mean values were compared using posthoc tests. Results: The results indicated significant variation in SBS among the three groups without treatment (p=0.011) and after sandblasting with 110 um alumina (p=

Background: Alumina particles from the grit blasting of Ti-alloy stems are suspected to contribute to aseptic loosening. An alumina-reduced stem surface was hypothesized to improve osseointegration and show comparable short-term outcomes to those of a standard stem. Methods: In this prospective, double-blind, randomized trial, 26 standard (STD) and 27 experimental new technology (NT) stems were implanted. The latter were additionally treated by acid etching and ice blasting to remove alumina particles from the grit-blasting process. Follow-up occurred at 12 and 24 months. Bone mineral density (BMD) around the stem was measured by a dual-energy x-ray absorptiometry device (DEXA). Radiographs were reviewed for alterations. Clinical scoring comprised the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and the Harris Hip Score (HHS). Survival rates were calculated up to 50 months. Results: Lower mean BMD and more severe cortical hypertrophies were found in the NT group. At 12 months, radiolucent lines were observed mostly in the metaphyseal zone for both groups, with a progression tendency in the NT group at 24 months. At 12 months, pain scores and the WOMAC total and physical activity scores were significantly lower in the NT group, without any differences thereafter. The number of NT stem revisions amounted to 6 (24%) and 11 (41%) at 24 and 50 months, respectively. Conclusion: In the NT group, unexpected catastrophic failure rates of 41% caused by early aseptic loosening were noted within 50 months. Compared with the STD stems, NT stems lead to poor clinical and radiographic results. Level of evidence: II. Trial Registration: NCT05053048. [ABSTRACT FROM AUTHOR]

In this work, the synergistic effect of hydrochloric-acid etching and inhibitors on the flotation separation of magnesite and dolomite in the sodium oleate (NaOL) system was studied. Flotation tests revealed that the synergistic effect of acid etching and sodium hexametaphosphate, sodium alginate, and sodium lignosulfonate on the separation of magnesite and dolomite was poor. Meanwhile, the synergistic effect of acid etching with sodium carboxymethyl cellulose (CMC) could regulate the flotation separation of magnesite and dolomite over a wide pH range. Moreover, the synergistic effect of acid etching and CMC increased the flotation difference between magnesite and dolomite from 15.73% to 67.17%, and the selective separation index increased from 1.38 to 2.89. Characterization by atomic force microscopy revealed that acid etching altered the surface morphology of magnesite and dolomite, roughening their surfaces. Contact angle measurements, Fourier transform infrared spectroscopy analysis, and zeta potential measurements indicated that the synergistic effect of acid etching and CMC changed the wettability, charge, and adsorption performance of dolomite, selectively inhibiting the adsorption of NaOL onto the surface of dolomite, thereby inhibiting dolomite flotation. However, it has minimal effect on the floatability of magnesite. [ABSTRACT FROM AUTHOR]

The surface treatment of chopped glass fiber (GF) can significantly improve the strength, impact resistance, and durability of epoxy resin (EP), and the homogeneity of GF modified EP material is better than that of continuous fiber reinforced EP, which has an important application in the engineering field. The effects of surface treatment and addition of chopped GF on the rheological behavior and mechanical properties of EP/modified chopped GF composites were studied by alcohol washing, coupling agent treatment, and acid etching modification methods. In addition, a reactive flame retardant containing phosphorus, nitrogen and bromine was synthesized, and the flame retardant application was studied in the EP/modified chopped GF system. The results show that the surface micromorphology of the chopped GF treated with acid etching is relatively rough, which can greatly increase the initial shear viscosity of the system, and the mechanical properties of the cured composites are significantly better than those of the GF treated with alcohol treatment and coupling agent. The chopped GF content of acid etching treatment is 2.0%, and the tensile strength of the composite is the highest, which is 59.75 MPa. When the flame retardant content is 10%, the peak heat release rate and total heat release of the composite are significantly lower than those of pure EP, and the mechanical properties are improved at the same time. [ABSTRACT FROM AUTHOR]

Titanium dioxide with suitable band edges is one of promising photocatalysts for water splitting. Nanotubes with one-dimensional structure can induce efficient charge transfers and hollow centers can provide large surface area for surface reactions. Modifying Ti foils for anodization can enhance light utilization of TiO 2 nanotube photoelectrodes. In this work, it is firstly to fabricate TiO 2 nanotube photoelectrodes on acid-etched Ti foils by anodization (MNT) for photoelectrochemical catalyzing water splitting. Different acid-etching durations are applied on Ti foils to induce various rugged surfaces. The resulting photoelectrodes present largely enhanced light utilization than that fabricated by the pristine Ti foil. The anodization duration is also optimized to find suitable lengths of MNT. The smallest overpotential of 524.7 mV at 10 mA/cm2 and Tafel slope of 167 mV/dec are obtained for the optimal MNT photoelectrode. The TiO 2 nanotubes grown on the pristine Ti foil shows the overpotential of 679.3 mV at 10 mA/cm2 and Tafel slope of 285 mV/dec. This result opens a blueprint for raising the photocatalytic ability by simply modifying the surface property of the conductive substrate. Other modifications may be applicable to enhance the roughness of Ti foils for growing more efficient MNT array as photocatalysis of water splitting. [Display omitted] • TiO 2 nanotube photoelectrodes are fabricated on acid-etched Ti foils by anodization. • Different acid-etching duration is used on Ti foil to induce various rugged surface. • Anodization duration is optimized to find the suitable lengths of TiO 2 nanotubes. • Smaller overpotential of 524.7 mV at 10 mA/cm2 and Tafel slope of 167 mV/dec are got. • High light absorbance and small charge transfer resistance are got for modified tube. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the effect of different hydrofluoric acid concentrations and etching times on the surface, chemical composition and microstructure of lithium disilicate. Material and Methods: Ninety specimens of pressed lithium disilicate (LDS) were obtained (IPS e.max Press, Rosetta SP and LiSi Press). The specimens of each material were divided in two groups according to the hydrofluoric acid concentration: 5% and 10% (n = 15/group), and subdivided according to the etching time: 20, 40 and 60 s (n = 5/group). Crystalline evaluations and chemical composition were performed through x‐ray diffraction (XRD) and energy‐dispersive x‐ray spectroscopy (EDS), respectively. Microstructural analyses were performed by scanning electron microscope (SEM), surface roughness (Ra), and material thickness removal evaluation. Thickness removal and Ra data were analyzed by ANOVA and Tukey test (p < 0.05). Results: XRD demonstrated characteristic peaks of lithium disilicate crystals, lithium phosphate and of a vitreous phase for all materials. EDS identified different compositions and SEM confirmed different surface responses to acid etching protocols. Material and etching time influenced Ra and material thickness removal (p < 0.05). Conclusion: Hydrofluoric acid concentration and etching time affect the surface characteristics of LDS differently. LiSi Press presented higher resistance to hydrofluoric acid etching compared to e.max Press and Rosetta SP. Clinical Significance: Applying the appropriate etching protocol is pivotal to avoid excessive material removal and to prevent jeopardize the mechanical and optical properties of the material. [ABSTRACT FROM AUTHOR]

The effect of acid etching on the floatability of dolomite and its mechanism of action were investigated by flotation tests, flotation kinetic fitting, surface roughness characterization, specific surface area analysis, XPS analysis, adsorption performance analysis and wettability analysis under sodium oleate system. The research results showed that acid etching increased the surface roughness and specific surface area of dolomite, exposing more active sites, strengthened the adsorption sodium oleate, enhanced the hydrophobic of dolomite, and thus improved the performance of dolomite. Moreover, regarding flotation kinetic fitting, the classical first-order model, first-order model with rectangular distribution of floatability, and the second-order kinetic model all displayed the R² values higher than 95%. Compare with other models, the classical first-order model exhibited the best fit. At a sodium oleate mass concentration of 60 mg/L, the k value of classical first-order for dolomite reached a maximum value of 1. 88 min-1 . However, in this case, before acid etching, the k value of classical first-order model for dolomite was only 1. 15 min-1 . These results further confirmed that acid etching could improve the flotation rate of dolomite. In summary, this study can provide a new research perspective for dolomite flotation, with a certain theoretical and practical significance. [ABSTRACT FROM AUTHOR]

Introduction: Polyetheretherketone, also known as PEEK, is a semicrystalline thermoplastic material with many advantages. Since its grey material, it has to veneering with composite resin to enhance its aesthetic appeal. Bonding PEEK and composite veneers poses challenges due to its inert surface. Aim: To assess and compare the Shear Bond Strength (SBS) between various polyetheretherketone materials and veneering composites following various surface treatments. Materials and Methods: The in-vitro study was conducted at KSR Dental College and Hospital in Tiruchengode, Tamil Nadu, India, over a period of three months from December 2022 to February 2023. A total of 108 PEEK discs were prepared for the study, divided into three groups: unfilled PEEK, 30% carbon reinforced PEEK, and 10% carbon + 10% graphite + 10% Polytetrafluoroethylene (PTFE) reinforced PEEK. The specimens underwent different surface treatments, including no treatment, sandblasting with 110 um alumina particles, and acid etching with 98% sulphuric acid. Additionally, 108 composite discs were prepared and bonded to the PEEK specimens using adhesive and resin cement. The bonded specimens were immersed in distilled water for 24 hours, and the Shear Bond Strength (SBS) was determined using a universal testing machine. Statistical analysis was performed using one-way ANOVA, and mean values were compared using posthoc tests. Results: The results indicated significant variation in SBS among the three groups without treatment (p=0.011) and after sandblasting with 110 um alumina (p=<0.001). The 30% carbon reinforced PEEK exhibited the highest SBS regardless of the surface treatments. Conclusion: Among the tested materials, 30% carbon reinforced PEEK demonstrated the highest SBS, regardless of the surface treatments. Acid etching yielded the highest SBS among the various surface treatments, irrespective of the type of PEEK material used. [ABSTRACT FROM AUTHOR]

Background The aim of this study was threefold. Firstly, it aimed to introduce and detail a novel method for chemically etching the bases of stainless-steel orthodontic brackets. Secondly, the study sought to investigate the structural alterations within the brackets’ microstructure following chemical etching compared to those with sandblasted bases, using electron microscopy analysis. Lastly, the study aimed to evaluate and compare the long-term durability and survivability of orthodontic brackets with chemically etched bases versus those with sandblasted bases, both bonded using the conventional acid etch technique with Transbond XT adhesive, over an 18-month follow-up period. Methods The study was a randomized clinical control trial with triple blinding and split-mouth study design and consisted of two groups. The brackets in the sandblasted group were prepared by sandblasting the intaglio surface of the base of the bracket with 50 µm SiO2 particles. Hydrofluoric acid was used to roughen the base in the acid-etched group. The bases of the brackets were viewed under an electron microscope to analyze the topographical changes. Results A total of 5,803 brackets (3,006 acid-etch, 2,797 sandblasted) in 310 patients were bonded, in a split-mouth design by the same operator. The patients were followed for 18 months. The failure rate of 2.59% and 2.7% was noted in an acid-etched and sandblasted group, respectively. There was a close approximation of curves in the Kaplan-Meier plot, and the survival distribution of the two groups in the log-rank (Mantel-Cox) test was insignificant; x2 = 0.062 (P value = 0.804). Conclusion Acid etching if the bases of the brackets can be used as an alternative to sandblasting furthermore acid etching can be performed on the chair side.

The tensile bond strength between zirconia subjected to different surface-pretreatment methods and methacryloyloxydecyl-dihydrogen-phosphate (MDP)-containing self-adhesive resin cement was evaluated herein. Eighty-eight cylindrical zirconia specimens were randomly divided into the following four groups based on the pretreatment method: (1) no treatment, (2) air abrasion, (3) HNO3/HF etching, and (4) zirconia-nanoparticle coating. The tensile bond strength of the zirconia−resin-cement complexes was investigated. One-way ANOVA and post hoc tests were performed at a 95% significance level, and the Weibull modulus was calculated. Fracture patterns were visualized by SEM. The surface roughness of the specimens without resin bonding was evaluated by AFM. The tensile bond strength of the specimens decreased as follows: Groups 3 > 4 > 2 > 1 (28.2 ± 6.6, 26.1 ± 5.7, 16.6 ± 3.3, and 13.9 ± 3.0 MPa, respectively). Groups 3 and 4 had significantly higher tensile bond strengths (p < 0.05) and lower fracture probabilities than those of Groups 1 and 2. They also showed both mixed failure and resin-cement cohesive failure, whereas Groups 1 and 2 showed mixed failure exclusively. The zirconia−resin tensile bond was stronger after HNO3/HF etching or ZrO2-nanoparticle coating than after air abrasion or no treatment. The estimated surface roughness decreased as follows: Groups 3 > 4 > 2 > 1. The combination of zirconia pretreated with HNO3/HF etching or ZrO2-nanoparticle coating and an MDP-containing self-adhesive resin cement can increase the clinical longevity of zirconia restorations by preventing their decementation.

Purpose: To evaluate the effect of different HF-etching protocols on the dissolution depth and micromorphology of the etched and adjacent surfaces of ultrathin glass-ceramic specimens. Materials and Methods: One hundred twenty specimens (6 x 6 x 0.3 mm) of leucite-reinforced glass-ceramic (LEU, IPS Empress, Ivoclar Vivadent) and lithium-disilicate-reinforced glass-ceramic (LD, IPS e.max, Ivoclar Vivadent) were prepared. Specimens were divided into 5 groups (n = 12) according to etching protocol: G1: control, untreated; G2: 5% hydrofluoric acid (HF) etching for 20 s (HF5%20s); G3: HF5%60s; G4: HF10%20s; and G5: HF10%60s. To analyze the dissolution depth, specimens were sectioned into two similarly sized halves using a chisel to create an internal surface (IS). Specimens were analyzed with scanning electron microscopy (SEM) on the following surfaces: HF application surface (AS), lateral surface (LS), internal surface (IS), and the surface opposite to the AS (OS). Dissolution patterns were identified. Data were submitted to one-way ANOVA and Bonferroni's test (a = 0.05). Dissolution depth data were submitted to Kruskal-Wallis and Mann-Whitney U-tests (a = 0.05). The prevalence of different dissolution patterns was analyzed using SEM. Results: HF gel applied on the AS also affected the adjacent surfaces of all specimens. Different dissolution patterns were observed, which were dependent of HF-etching protocol and proportion of the glass phase in the ceramic. These patterns were categorized into four types for LEU (I-IV) and three for LD (I-III) according to the micropore size. The greater the micropore size, the more pronounced the etching pattern (p < 0.001). Higher HF times and concentrations showed prevalence of more severe etching patterns. HF10%60s produced greater dissolution depth in both materials when compared with other HF-etching groups (p < 0.05). Conclusion: Hydrofluoric acid etching not only affects the surface upon which it is applied, but internal, lateral and even opposite edges of glass ceramic. Different dissolution patterns and depths can be formed which are dependent of hydrofluoric acid concentration, application time, and proportion of the glass phase in the ceramic. [ABSTRACT FROM AUTHOR]

This study investigated the various parameters of the sandblasting, acid-etching, and anodizing processes for 68 different states of surface treatment of dental implant fixtures using the SLA + anodizing procedure. To examine each of the fixture surfaces, 9 different tests were performed, including AFM, FESEM, EDAX, CHNO, XRD, EDAX-Map, MTT, Surface energy, and bone formation tests, to thoroughly examine the surfaces from different aspects. 450 dental implant fixture samples were used due to the high number of types of tests, variables, and specific conditions of each experiment. To validate the results, the tests were compared with SLA methos as a common method for dental implant treatment. The final results indicate the superiority of the process numbered 35 (sandblast particle size 75 μm; spraying pressure of sandblast particles 4 bar; sandblast particle spraying angle 30 deg; temperature of acid etching 75°C; time of acid etching 6 min, anodizing voltage 100 V; duration of anodizing 5 min), with the SLA + anodizing method. State number 35 had a surface roughness of 2.018 μm 97% cellular viability; 56.2 millinewton per meter surface energy, and standard chemical composition and mineralization after treatment. Within a period of 6 days, it completely outperformed all other states. [ABSTRACT FROM AUTHOR]

Titanium surface modifying for the implants by chemical and physical methods generally used with the aim of achieving better osseointegration. This study examines the effects of thermochemical treatments on titanium's nanoscale surface. The physical properties of the surface and topography of CPTi are influencing the outcomes of implant surgery. Method: Three implants surface prepared: first group untreated CpTi (control), second group surface modified by etching with H₂SO4 acid within 80Cº thermal application, and 3rd. group surface modified with HCL and 80Cº thermal application during acid etching. The surface characterized by SEM, AFM, and wettability test analysis of data was done by using statistical SPSS v 22 Result: higher roughness 25.1nm shown when etching performed by H2SO4 with 80C heating for 10min, while the surface roughness was 17nm when etched with HCL under same conditions. The wettability test revel increase in hydrophilicity when H2SO4 used for etching and the contact angle reduced to 56.55 degree. Conclusion: thermochemical etching is an effective surface modification technique that can enhance the properties of commercial pure titanium. The modified surface layer results in enhanced surface roughness, and improved wettability. These properties make the material suitable for various industrial and biomedical applications. [ABSTRACT FROM AUTHOR]

Copper oxides tend to agglomerate on the surface of CeO2, with a high amount of Cu. In this study, a CeO2 catalyst with a high CuO doping amount was treated with nitric acid to improve its catalytic performance for soot oxidation. The effect of acid etching on the structural properties of the CuO-doped CeO2 catalyst were elucidated. The characterization results indicated that aggregated CuO particles formed over CuCe. The acid etching resulted in a remarkable increase in the surface area of CuCe. Additionally, acid etching promoted the formation of surface-adsorbed oxygen species and oxygen vacancy, and reduced the content of CuOx species with weak interaction with CeO2. The soot temperature-programmed oxidation results show the acid etching of CuCe catalyst could reduce the T50 from 443 to 383 °C. The isothermal reaction results also suggest that acid etching of CuCe leads to an increase in reaction rate from 16.2 to 46.0 μmol min−1 g−1. [ABSTRACT FROM AUTHOR]

[Display omitted] The introduction of nitrogen vacancies into polymeric carbon nitride (PCN) has been attested to be a reliable strategy to enhance photocatalytic performance. Nitrogen vacancies were considered as active sites to promote the adsorption of target molecules and capture photoexcited electrons to inhibit the recombination of charge pairs, accelerate photoinduced electrons to participate in photocatalytic reaction. In this paper, a series of PCN with rich nitrogen vacancies were prepared by etching of chromic acid solution. Sample 20KCSCN had the highest photocatalytic performance whose evolution efficiency of CO 2 to CO and CH 4 can reach 3.9 and 0.5 μmol·g−1·h−1, respectively. These evolution efficiencies are 2.9 and 4 times higher than that of the PCN. Meanwhile, 20KCSCN demonstrates high CO conversion selectivity and stability. The successful introduction of nitrogen vacancies not only increases the active sites of PCN surface, but also optimizes the optical structure, which dramatically boosts the separation of photoexcited charge pairs and the reduction capacity of photogenerated electrons. The enhancement mechanism for photocatalytic CO 2 reduction performance of PCN was proposed. Besides, photocatalytic H 2 evolution experiments were performed on all samples to confirm the universality of PCN photocatalytic activity enhancement etched by chromic acid solution. H 2 evolution rate on 20KCSCN can reach 652 μmol·g−1·h−1, which is 1.6-fold higher than that on PCN (254 μmol·g−1·h−1) after 4 h irradiation under a 300 W Xe lamp. This work offers new venue for introducing nitrogen vacancies in PCN to regulate photoexcited charge pairs transfer. The photocatalytic enhancement of CO 2 reduction could be used to alleviate the serious issue of excessive CO 2 emission and energy crisis. [ABSTRACT FROM AUTHOR]

With the flourishing development of the photovoltaic industry, the waste of silicon slime generated by photovoltaic cutting has been a serious environmental problem, along with silicon resource waste. In this paper, the waste silicon slime produced by the photovoltaic industry was used as raw materials. Porous silicon particles were synthesized with the magnesium thermal reduction method, combined with hydrofluoric acid etching. The porous silicon can be applied to be the anode material of lithium-ion batteries. The synergistic effect of magnesium thermal reduction and acid etching on the preparation of porous silicon materials was studied. A lower heating rate of 5 °C/min will result in less heat accumulation, which can avoid the formation of large-sized Si/MgO composite particles and obtain a well-dispersed morphology. After a current density of 100 mA·g−1, the reversible capacity of porous silicon anode is 751.1 mAh/g after 50 cycles. Compared with commercial nano silicon, its cycle stability and cycle performance have been improved, which provides a new approach for green reutilization of waste silicon slime in the photovoltaic industry. [ABSTRACT FROM AUTHOR]

The aim of this study is to assess the influence of various Er:YAG laser energies on dentin surface micromorphology and dentine-resin shear bond strength (SBS). Eighty dentin specimens were prepared and divided randomly into ten groups: control group (CG), phosphoric acid-etched group (AG), four laser-conditioned groups treated with various pulse energies of 40, 60, 80, and 100 mJ (L40, L60, L80, L100), and four laser-conditioned acid-etched groups (LA40, LA60, LA80, LA100). Two specimens from each group underwent scanning electron microscopy examination, while the remaining six were subjected to the dentin-resin SBS test. Statistical analyses included Welch's analysis of variance (ANOVA), followed by post hoc Tamhane's T2 multiple comparisons test, Pearson's correlation, and Fisher's exact test. Pulse energies of 60, 80, and 100 mJ fully exposed the dentin tubule orifices, although 100 mJ lead to microcracks. Laser-conditioned surfaces exhibited smaller tubule diameters compared to acid-etched surfaces, and tubule diameters positively correlated with dentin-resin SBS. Laser-conditioned groups showed lower SBS values, while laser-conditioned acid-etched groups demonstrated higher SBS values. No significant relationship was observed between dentin surface roughness and SBS. The range of laser energies used for dentin conditioning had limited effects on SBS or failure modes. Laser conditioning with energies ranging from 40 to 100 mJ effectively removes the smear layer from the dentin surface. However, to enhance dentin-resin bond strength, further acid etching of the laser-conditioned surface is necessary. [ABSTRACT FROM AUTHOR]

Abstract Objective This study aimed to analyze the longitudinal bond strength of a universal adhesive and chemically characterize the dentin substrate under different acid etching protocols. Methodology Dentin samples were etched with polyacrylic acid 25% (PAA) for 10 seconds (n=3) and phosphoric acid 32% (PA) for 15 seconds (n=3) and analyzed by Fourier transform infrared spectroscopy – attenuated total reflectance (FTIR-ATR) before and after treatment. For collagen degradation, samples (n=12) were divided into 3 groups: PAA, PA, and Deionized water (control), and analyzed by the quantity of solubilized type I collagen C-terminal cross-linked telopeptides and solubilized C-terminal peptide in relation to total protein concentration (ICTPtp and CTXtp) and by their ultimate tensile strength (UTS). For the adhesive interface analysis, dentin samples (n=72) were divided into 3 groups: PAA, PA, and Self-etch (SE), and subdivided into 2 groups: 24 h (baseline) and 1 year. The following tests were performed: microtensile bond strength (μTBS) (n=48), scanning electron microscopy (SEM) (n=12), and nanoleakage (n=12). Results The FTIR of PAA showed lower reduction of the peaks in the phosphate group when compared to PA. For ICTPtp, PA showed a significantly higher value. For CTXtp, PA and PAA groups failed to statically differ from each other. UTS was significantly lower for PA. For μTBS, storage time significantly affected bond strength. The results were unaffected by the etching protocol. For SEM, after 1 year, PA had little evidence of degradation in the upper third of the adhesive interface in comparison to the other groups. Nanoleakage showed no considerable silver impregnation after 1 year in the SE group. Conclusion The use of PAA prior to a universal adhesive (when compared to PA) represents a less aggressive type of etching to dentin. However, self-etching still seems to be the best option for universal adhesive systems that have functional monomers in their composition.

Proanthocyanidin (PA), as a kind of natural plant polyphenol, have a variety of biological functions, such as promoting remineralization, inducing collagen cross-linking, inhibiting protease activity and inhibiting bacteria. Therefore, PA could be broadly used in the clinical application of treatment and repair of deep caries in the future; for example, PA could promote dentin remineralization, improve resin-dentin bonding durability and improve the dentin acid erosion effect. This application potential of PA arises from several features, firstly, PA can not only promote dentin remineralization on its own or with other remineralizers but also exhibits antibacterial effects, which can inhibit acid production while reducing the formation of cariogenic pathogens and their biofilms. Based on the above features, PA can reduce the incidence of caries disease; thus, PA improves deep caries and long-term effects after treatment. In addition, PA added to adhesives or etch agents can improve the etching and bonding effect of dentin by inducing collagen cross-linking and inhibiting protease activity, thus achieving the ultimate goal of improving the bonding performance of deep caries. This paper summarizes recent progress of research on PA for the treatment and repair of deep caries, including the promotion of dentin remineralization and antibacterial activity as well as the improvement in dentin bonding and acid etching effect, to provide a more comprehensive reference for treating and restoring deep caries in clinical practice.

Adhesion of zirconia is difficult; thus, etching agents using several different methods are being developed. We investigated the effects of surface treatment with commercially available etching agents on the bond strength between zirconia and resin cement and compared them with those achieved using air abrasion alone. We used 100 zirconia blocks, of which 20 blocks remained untreated, 20 blocks were sandblasted, and 60 blocks were acid-etched using three different zirconia-etching systems: Zircos-E etching (strong-acid etching), smart etching (acid etching after air abrasion), and cloud etching (acid etching under a hot stream). Each group was subjected to a bonding procedure with dual-polymerized resin cement, and then 50 specimens were thermocycled. The shear bond strengths between the resin cement and zirconia before and after the thermocycling were evaluated. We observed that in the groups that did not undergo thermocycling, specimens surface-treated with solution did not show a significant increase in shear bond strength compared to the sandblasted specimens (p > 0.05). Among the thermocycled groups, the smart-etched specimens showed the highest shear bond strength. In the short term, various etching agents did not show a significant increase in bond strength compared to sandblasting alone, but in the long term, smart etching showed stability in bond strength (p < 0.05).

Surface modifications for titanium, a material of choice for dental implants, can greatly alter the surface micro/nanotopography and composition of implants, leading to notable enhancements in their hydrophilicity, mechanical properties, osseointegration performance, and antibacterial performance, as well as their impacts on osteoblast activity and bone formation processes. This article aims to update titanium surface modification techniques for dental implants from the past to the present, along with their effects on osteoblasts and bone formation, by thoroughly summarizing findings from published studies. Peer-reviewed articles published in English consisting of in vitro, in vivo, and clinical studies on titanium dental implant surface treatments were searched in Google Scholar, PubMed/MEDLINE, ScienceDirect, and the Scopus databases from January 1983 to December 2023 and included in this review. The previous studies show that implant surface roughness, condition, and hydrophilicity are crucial for osteoblast adhesion and growth. While various techniques enhance osseointegration comparably, one of the most common approaches to accomplishing these properties is sandblasting large-grit acid etching surface treatment and coating with hydroxyapatite or chitosan. In conclusion, this review points out the efficacy of different subtraction and addition techniques in enhancing the surface properties of titanium dental implants, promoting favorable outcomes in terms of osteoblast activity and bone formation in various degrees. However, most existing studies predominantly compare treated and non-treated titanium, revealing a need for more comprehensive studies comparing the effects of various modification techniques. Moreover, further investigation of factors playing a role in the dynamic osseointegration process in addition to osteoblasts and their functions, as well as improved surface modification techniques for the treatment of compromised patients, is greatly required.

Objective: This study aimed to investigate the effects of laser irradiation applied to zirconia and tooth surfaces on shear bond strength (SBS) compared with acid etching and sandblasting. Background: The effect of laser irradiation on the bond strength between zirconia and adhesives is a controversial issue for dentin surface treatments. In addition, the effects of different combinations of surface treatments to increase adhesion on both the zirconia and dentin surfaces remain unclear. Materials and methods: A total of 90 tooth samples were assigned into groups according to various pretreatments: control group was left untreated, acid etching, and Erbium, Chromium:Yttrium Scandium Gallium Garnet (Er,Cr:YSGG) laser irradiation group (15 Hz, 2 W). In addition, the zirconia specimens were separated into three groups (n = 10) according to the different surface treatments performed: sandblasting (120 lm Al2O3), Er,Cr:YSGG laser (15 Hz, 2 W), and as untreated surface. The zirconia samples were cemented to the dentin surface using dual-cure resin cement and subjected to an SBS test at a speed of 0.5 mm/min under a universal testing machine until fractures occurred in the bonding surface. Results: The highest SBS values were observed in Group tooth acid (TA)-zirconia Er,Cr:YSGG laser (ZL), followed by Group tooth Er,Cr:YSGG laser (TL)-zirconia sandblasting (ZS) and Group TA-zirconia control (ZC). The lowest SBS values were found in Group TA-ZS. Significant intergroup difference was noted between Group TA-ZL, Group tooth control (TC)-ZC, Group TL-ZS, and Group TC-ZC. However, no significant difference was noted between Group TA-ZL, Group TL-ZS, and Group TA-ZC. Conclusions: Acid etching and laser treatments applied to the dentin and zirconia surfaces were found to be effective techniques for improving the zirconia–dentin bond, respectively. Clinical Trial Registration number: 33216249-604.01.02-E.24308. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate whether the composite cement tensile bond strength is affected by different firing cycles or etching conditions on zirconium-incorporated lithium-silicate glass ceramics. Materials and Methods: Specimens (N=53) were prepared from blocks of zirconium-incorporated lithium-silicate glass ceramic (ZLS, Dentsply Sirona) with specimen dimensions of 12.5 x 14 x 2 mm (L x W x H, respectively). The specimens were subjected to different firing cycles and etching conditions. They were subsequently cemented onto titanium rods (grade V Ti-alloy, 4.8 mm in diameter, and 25.4 mm in length) with self-adhesive composite cement (TheraCem, Bisco), and then tested for tensile bond strength (TBS). The least-square means linear regression model was used to analyze the effects on TBS using JMP Pro 14 (SAS) and the post-hoc Tukey test with α=0.05. Results: The TBS was significantly affected by etching duration (p<0.001) and firing cycles (p<0.001), but was not significantly affected by etchant concentration (p=0.31). The highest TBS peak (4.83 MPa) on the fit curve was observed at 45 s of etching time. The lowest TBS was observed at 20 s (3.02 ± 0.28 MPa) etching time. In terms of firing cycles, 1 firing cycle (4.00 ± 0.71 MPa) provided the highest TBS. In contrast, the lowest TBS was observed for as-machined ZLS specimens but without a firing step (3.29 ± 0.53 MPa). Conclusions: Changing the etching time and firing conditions of the specimens had a significant effect on the compos- ite cement tensile bond strength to zirconium-incorporated lithium-silicate glass ceramic. In contrast, etching the specimens with different acid concentrations, 5% or 9.6% of HF, did not significantly change the composite cement tensile bond strength. [ABSTRACT FROM AUTHOR]

Objectives: The purpose of the present prospective and randomized clinical trial was to evaluate the clinical performance of noncarious cervical lesions (NCCLs) restored with different adhesion strategies on the dental substrate. Method and materials: An adhesive restorative system (Single Bond Universal/Z350XT) with and without selective enamel conditioning was evaluated, as well as a resin-modified glass-ionomer cement (Vitremer), with and without pretreatment with ethylenediaminetetraacetic acid (EDTA). Two operators placed a total of 200 restorations in 50 patients (four restorations per patient). Data from decayed, missing, and filled teeth (DMFT), visible plaque, and gingival bleeding were collected prior to the restorations and at each evaluation time. All restorations were evaluated using the modified United States Public Health Service (USPHS) evaluation system at baseline, and at 6 and 12 months. Data were analyzed by the Friedman, chi-square, Cochran, Wilcoxon, and multiple logistic regression analysis tests (P = .05). Results: There was a gradual and significant increase in DMFT with a difference among the three evaluations (P = .001). There was no difference for the Visible Plaque Index over time (P = .28); however, there was a significant reduction in the Gingival Bleeding Index between the baseline and the other evaluations (P = .001). There was no statistically significant difference among groups and periods of evaluations (P > .05). Regarding logistic regression, the model as a whole was statistically significant (P = .034). Conclusion: The four different adhesion strategies in the NCCL restorations presented similar clinical performance after 1 year of follow-up. [ABSTRACT FROM AUTHOR]

Purpose: This meta-analysis investigated the influence of different acid etching times on the retention rate of pitand- fissure sealants based on clinical trials with a minimum duration of two years. Materials and Methods: A literature search was carried out in electronic databases along with hand searching to identify clinical trials that evaluated pit-and-fissure sealants in permanent molars. From 1280 identified abstracts, 195 studies were selected for full-text analysis, and 28 studies with 36 test groups were included in this metaanalysis. Test groups with etching times of 15 (n = 3), 20 (n = 2), 30 (n = 10), 40 (n = 1) and 60 s (n = 20) were found. Incidence rates of pit-and-fissure sealant losses were modelled using negative binomial regression. Results: The regression analysis did not reveal a significant influence of etching time on the survival of pit-and-fissure sealants based on the identified and included clinical trials. Conclusions: Due to the limited number of clinical data for 15 and 20 s, conclusions regarding very short acid etching times were not possible. On the basis of regression analysis, a minimum of 30-s acid etching might be sufficient prior to fissure sealing. [ABSTRACT FROM AUTHOR]

Purpose: To determine the effects of ceramic-surface conditioning and aging on the bond strength between composite cement and zirconia-reinforced lithium-silicate glass-ceramics (ZLS) under simulated clinical conditions. Materials and Methods: ZLS disks (Celtra Duo, Dentsply Sirona, n = 110 test group n = 10, diameter: 8.3 mm, height: 3.4 mm) were assigned to four surface-conditioning groups: (I) 30 s of ~5% hydrofluoric-acid etching (Vita Ceramics Etch, Vita; HF), silanization (Calibra Silane; SIL); (II) successive contamination with saliva and silicone (CONT), HF, SIL; (III) CONT, tribochemical silicatization (CoJet), SIL; (IV) HF, SIL, application and light polymerization of an adhesive (Prime&Bond Active), CONT, reapplication and light polymerization of the adhesive. The ZLS disks were bonded to composite-resin cylinders in acrylic tubes (inner diameter: 3.3 mm) using self-adhesive composite cement (Calibra Universal). The tensile-bond strength (TBS) was measured after both 24 h and 6 months of water storage (WS). Additional aging protocols were tested for group I (3-day WS; 30-day WS including 7500 thermocycles between 6.5 and 60°C; 150-day WS including 37,500 thermocycles). Results: After 24 h, the mean TBS ranged between 21 MPa (group III) and 30-35 MPa (remaining groups). With the exception of 3-day WS, TBS was statistically significantly reduced by aging. The greatest reduction was observed for silicatized specimens (group III, mean TBS after aging: 9.8 MPa). Conclusion: Both ceramic surface conditioning and aging had a statistically significant effect on the bond strength between composite cement and ZLS. A treatment protocol based on tribochemical silicatization cannot be recommended for the adhesive cementation of ZLS. [ABSTRACT FROM AUTHOR]

The aim of this study was to assess the effect of phytic acid and to compare it with the phosphoric acid etching through a systematic review. systematic search was carried out using PubMed/MEDLINE, Cochrane library, Indmed, Scopus, and Liliacs databases conducted upto January 2022. In vitro studies comparing phytic acid and phosphoric acid as an etchant on tooth surfaces that performed bond strength, smear layer removal, collagen degradation and monomer penetration were included. The risk of bias was assessed considering Checklist for Reporting In-vitro Studies guidelines. Five studies were chosen for full-text assessment out of 830 that were potentially eligible. The studies found that phytic acid improved bond strength, collagen degradation, smear layer removal, and monomer penetration. Every study had a moderate-to-high risk of bias. Phytic acid enhanced the etch and rinse adhesive's binding strength to dentin, effectively eradicated the smear layer, protected dentin collagen from degradation, and had better resin infiltration and minimal effect on pulpal cells. [ABSTRACT FROM AUTHOR]

Enrichment of As and Au at the overgrowth rims of arsenian pyrite is a distinctive feature of Carlin-type gold ores. Revealing distribution of such key elements in high resolution is of fundamental importance yet often proves challenging. In this study, repeated non-oxidative acid etching of ore samples from Shuiyindong gold deposit was applied to enable elemental depth profiling of gold-bearing arsenian pyrite grains. ICP-OES and AAS were used to determine the dissolved Fe, As, and Au concentrations in each of the etching solutions, and XPS was carried out to exam the etched mineral surfaces. In contrast to conventional ion beam etching that may cause substantial sample damage, our acid etching method does not seem to significantly alter the composition and chemical state of the samples. The etched depths directly converted from the measured elemental concentrations can reproducibly reach a very high resolution of ~ 1 nm, and can be conveniently controlled through varying the etching time. While the Fe and As depth profiles consistently reflect the surface oxidation property of arsenian pyrite, the Au profile displaying an obvious upward trend reveals the ore fluid evolution at the late stage of mineralization. Based on our experimental results, we demonstrate that our wet chemistry method is capable of effective depth profiling of gold ore and perhaps other geological samples, with advantages surpassing many instrumental techniques including negligible sample damage, nanoscale resolution as well as isotropic etching. [ABSTRACT FROM AUTHOR]

Unexpected results and negligence can lead to mishaps in the dental operatory. With the trend of using tooth-colored restorations, mishaps have also increased, which are sometimes ignored due to a lack of knowledge. Although resin-based restorative materials are considered safe, their constituents can leach out and cause allergies in patients as well as dental professionals. Safe-handling of these resin-based materials is critical due to increased risk of occupational health hazards. Most of the allergies caused by resins are related to monomers based on methacrylic acid, which is found in almost all types of dentin bonding agents. Also, it is estimated that 5%–10% of all allergic contact dermatitis reports in dental professionals are due to contact with methacrylate. On the contrary, 37% phosphoric acid in etchant results in necrosis and ulcerative lesions due to vascular nature of the oral cavity. The purpose of this article is to help dentists to become aware of allergies/mishaps that can occur due to bonding agents and phosphoric acid, thereby leading to prevention and their early management. [ABSTRACT FROM AUTHOR]

One step fabrication of SiC catalytic filter is currently limited by the mismatched calcination temperature between SiC filter (>1700°C) and the catalysts (<800°C), and the difficulty in the chemical immobilization of catalysts. Here, a SrTi1−xCoxO3‐SiC (STC‐SiC) catalytic filter was directly fabricated from raw SiC grains and STC precursor oxides (SrCO3, TiO2, and Co3O4) via a single‐step reactive thermal processing (SRTP) approach, which significantly reduced energy consumption and sintering time over 50%. Acid etching enables the active TiO2 and Co3O4 nanoparticles spontaneously formed on STC catalysts in STC‐SiC catalytic filter (STC‐SiC‐A), which induces the generation of oxygen vacancies and facilitates the adsorption and activation of O2 and NO. The STC‐SiC‐A catalytic filter exhibits highly competitive NO oxidation of 60% and complete dust interception (100%) at 360°C. This work demonstrates an efficient and rapid processing technique of SiC based catalytic filters, which can also be implemented on other ceramic‐based catalytic filters. [ABSTRACT FROM AUTHOR]

This study deals with the issue of copper separation from acidic etching solutions formed during the process of production of printed circuit boards (PCBs) for the electrical and electronic industries. The article describes the selected methods of copper separation and summarizes the results of an experiment, in which the efficiency of copper recovery from the depleted acid solutions by the cementation and precipitation method was verified. In the process of cementation, iron in the form of metallic swarf was used as a precipitant. To verify the efficiency of the precipitation method, CaCO3 limestone, Ca(OH)2 calcium hydroxide and NaOH solution were used. During the measurement, the amount of Cu in the solution was observed for both methods in dependence on time, temperature, and pH.

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Objective: To find out what the acid-base resistant zone (ABRZ) is and the mechanism of its formation. Material and Methods: This systematic review was based on the search of laboratory studies in which selfetching adhesive systems were used. The electronic database PubMed was used for the search. The search began on August 2021 and ended on June 2022. We have analyzed the materials and methods of each research and entered them in the appropriate tables to give a clearer assessment of the obtained results. Results: This systematic review included 15 full-text articles published from 2011 to 2019. The ABRZ is formed on both dentine and enamel. On dentine, the ABRZ is formed only when using self-etching adhesive systems; on the enamel, on the contrary, the step of preliminary etch and rinse contributes to the formation of a thicker ABRZ. The functional monomer MDP and fluorine increase the thickness of the ABRZ and provide a hybrid layer /ABRZ boundary without defects and erosions. Conclusion: Self-etching adhesive systems ensure the creation of an ABRZ resistant to acid-base tests. This phenomenon can provide the resistance of tooth tissues to demineralization, and therefore increase their resistance to caries. [ABSTRACT FROM AUTHOR]

ABSTRACT Objective: This study assessed whether the use of a silane coupling agent influence the bond strength of two universal adhesives to ceramic or resin CAD/CAM blocks. Methods: Forty-eight samples were obtained from each resin nano-ceramic hybrid block (RCBs) and lithium disilicate ceramic blocks (LD). Samples were treated with silane with MDP (Monobond - S-MDP), silane without MDP (Prosil - PS), and no silane application (Control - Ctr) followed by universal adhesive with silane (UAS) and without silane (UA) (n=8). Three polyurethane tubes (1.5 mm of internal diameter) were positioned in each sample treated surface and filled with a dual cured resin cement. Bond strength was assessed by microshear bond strength test and failure analysis was performed for all samples. Results: For the RCBs, UAS presented the highest bond strength values (p=0.004). Silane application was not significant in bond strength values (p=0.444). For LD, silane application was significant in bond strength values (p

Copper oxides tend to agglomerate on the surface of CeO2, with a high amount of Cu. In this study, a CeO2 catalyst with a high CuO doping amount was treated with nitric acid to improve its catalytic performance for soot oxidation. The effect of acid etching on the structural properties of the CuO-doped CeO2 catalyst were elucidated. The characterization results indicated that aggregated CuO particles formed over CuCe. The acid etching resulted in a remarkable increase in the surface area of CuCe. Additionally, acid etching promoted the formation of surface-adsorbed oxygen species and oxygen vacancy, and reduced the content of CuOx species with weak interaction with CeO2. The soot temperature-programmed oxidation results show the acid etching of CuCe catalyst could reduce the T50 from 443 to 383 °C. The isothermal reaction results also suggest that acid etching of CuCe leads to an increase in reaction rate from 16.2 to 46.0 μmol min−1 g−1.

Purpose: To evaluate whether different etching methods with reduced etching times would improve the enamel bonding efficacy of universal adhesives. Materials and Methods: Three enamel etching methods were evaluated - 1. phosphoric acid ester monomer etching (PPM); 2. phosphoric acid etching (PPA); and 3. polyalkenoic acid etching (PLA) - as were three universal adhesives: 1. BeautiBond Universal (BU); 2. Prime&Bond elect (PE); and 3. Scotchbond Universal Adhesive (SU). The shear bond strengths of the universal adhesives to ground enamel and ground enamel etched for 1, 5, 10, and 15 s with different etching methods were determined after 24 h and 10,000 thermal cycles. Surface roughness average (Ra) and surface area ratio (surface area:planar area) were measured using a confocal laser scanning microscope. Field-emission scanning electron microscope (FE-SEM) observations of enamel with different etching protocols were also conducted. Results: The bond strengths of universal adhesives to enamel subjected to PPA etching with maximum times of 1-15 s and PLA etching for 15 s were significantly higher than those to ground enamel. The bond strength to enamel subjected to PPM etching did not increase and was similar to that for ground enamel. PPA and PLA etching were effective at increasing the Ra and surface area ratio of enamel. Although both values were significantly higher than those of ground enamel, those subjected to PPA etching were significantly higher than those which underwent PLA etching. In addition, the Ra and surface area of enamel subjected to PPM etching were similar to those of ground enamel, regardless of the etching time. Conclusions: Phosphoric acid etching for <1-15 s and polyalkenoic-acid etching for 15 s both improve the bonding of universal adhesives, the Ra, and the surface area ratio of enamel. However, phosphoric acid ester monomer etching was not effective, regardless of the etching time. [ABSTRACT FROM AUTHOR]

Mn3O4-Fe2O3 composite catalysts are in-situ synthesized via advanced oxidation followed by modifying with hydrochloric acid to improve the catalytic toluene oxidation performance. Mn3O4-Fe2O3 modified with 1.0 M HCl (A-1.0) exhibited best activity of toluene oxidation. The temperature of 50% toluene conversion is 245 °C and the temperature of 90% conversion is 279 °C. There are much more abundant surface lattice oxygen species and higher amount of high valence manganese and iron ions on A-1.0 catalyst, which are beneficial for improving catalytic activity. In-situ DRIFTs indicated that benzaldehyde and benzoic acid are main intermediate products on A-1.0 catalyst during toluene oxidation.

Silicon plays an important role in the development of high-energy Lithium-ion batteries. However, the high volume expansion rate (>300%) makes it a commercially unfeasible independent Lithium-ion battery anode material. In this work, we adopt P and Sr complex modification and increase the cooling rate to refine the microstructure of Casting Al-20Si alloy, then acid etching Al-20Si alloy ingot to prepare porous silicon. The as-prepared silicon has a three-dimensional dendritic porous structure based on the SEM morphology characterization. The porous silicon electrode was prepared with Si powder: acetylene black: binder in a ratio of 2:1:1. The electrolyte solution was 1 M LiPF6/EC:EMC: DMC = 1:1:1 (V/V) with or without 5% FEC. In the electrolyte solution without 5% FEC, the first charge and discharge capacities of the porous silicon electrode are 2924.8 mAh/g and 1910.1 mAh/g, and the coulombic efficiency is about 65.31%. In the electrolyte solution with additive 5% FEC, the first charge and discharge capacities are 3444.6 mAh/g and 2469.5 mAh/g, respectively. Its first cycle coulombic efficiency is 72.19%. After adding 5% FEC into the electrolyte, the main component of SEI film is the decomposition product of FEC, which can effectively inhibit the decomposition of electrolyte solvent at a low potential and improve the specific capacity of the battery. [ABSTRACT FROM AUTHOR]