Effect of different occlusal materials on peri-implant stress distribution with different osseointegration condition: A finite element analysis.

AIM: Studies have not been done to evaluate the peri-implant stress exerted by materials(like PEEK and resin matrix ceramics) in different osseointegration conditions. To investigate the effect of different occlusal materials on peri-implant stress distribution with different osseointegration condition using finite element analysis. SETTINGS AND DESIGN: Eighteen different 3D FEA models of implant fixed with abutment were created involving 6 different occlusal materials (Heat cured temporary acrylic resin (PMMA), Bis-GMA, PEEK, Lithium disilicate, Resin matrix ceramics and translucent Zirconia) and different osseointegrated conditions (50%, 75%, 100%). MATERIALS AND METHODS: Models were subjected to loading vertically and obliquely followed by evaluation of stress distribution. STATISTICAL ANALYSIS USED: The results of the simulation obtained were analysed in terms of Von mises, maximum principal and minimal principal stresses using descriptive stastistics. RESULTS: PMMA (40.14 MPa on vertical loading and 66 MPa on oblique loading) resulted in the highest stresses and lithium disilicate (24 MPa on vertical loading and 52.40 MPa on oblique loading) resulted in least stresses among all the crown materials. Upon oblique loading, von Mises stress increases except for translucent zirconia and lithium disilicate (52.444 MPa on 50%, 47.733 MPa on 75%, and 43.973 MPa on 100% osseointegration). Minimal principal stress values decreased with increase in osseointegration upon oblique loading for PMMA, BisGMA, and PEEK. CONCLUSION: Translucent zirconia and lithium disilicate offer a better stress transmission. Minimal principal stress values of PEEK and BisGMA decreased with increasing osseointegration.

Integrating gravity-driven ceramic membrane filtration with hydroponic system for nutrient recovery from primary municipal wastewater.

In this study, a gravity-driven membrane (GDM) filtration system and hydroponic system (cultivating basil and lettuce) were combined for nutrient recovery from primary municipal wastewater. The GDM system was optimized by increasing the periodic air sparging flow rate from 1 to 2 L/min (∼15 hr per 3-4 days), resulting in a ∼52% reduction of irreversible fouling. However, the total fouling was not alleviated, and the water productivity remained comparable. The GDM-filtrated water was then delivered to hydroponic systems, and the effects of hydroponic operation conditions on plant growth and heavy metal uptake were evaluated, with fertilizer- and tap water-based hydroponic systems and soil cultivation system (with tap water) for comparison. It was found that (i) the hydroponic system under batch mode facilitated to promote vegetable growth with higher nutrient uptake rates compared to that under flow-through feed mode; (ii) a shift in nutrient levels in the hydroponic system could impact plant growth (such as plant height and leaf length), especially in the early stages. Nevertheless, the plants cultivated with the GDM-treated water had comparable growth profiles to those with commercial fertilizer or in soils. Furthermore, the targeted hazard quotient levels of all heavy metals for the plants in the hydroponic system with the treated water were greatly lower than those with the commercial fertilizer. Especially, compared to the lettuce, the basil had a lower heavy metal uptake capability and displayed a negligible impact on long-term human health risk, when the treated water was employed for the hydroponic system.

An evaluation of antagonist enamel wear opposing full-coverage zirconia crowns versus other ceramics full-coverage crowns and natural enamel - An umbrella review.

AIM: The aim of this umbrella review was to systematically review the systematic reviews on antagonist enamel wear opposing zirconia crowns compared to other ceramics and natural enamel. SETTINGS AND DESIGN: This was an umbrella review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. MATERIALS AND METHODS: An electronic search of PubMed, Cochrane Central, EBSCOhost, and Google Scholar search engines for articles published from January 1, 2013, to January 1, 2023, was conducted using keywords "enamel wear," "zirconia," "feldspathic," "dental ceramics," and "Y-TZP" to identify systematic reviews on antagonist enamel wear opposing zirconia crowns compared to other ceramics and natural enamel. STATISTICAL ANALYSIS USED: Qualitative analysis. RESULTS: A total of 86 articles were obtained through electronic search, of which four articles were selected after abstract screening that met the inclusion criteria for evaluating antagonist enamel wear. As compared to feldspathic groups, zirconia had substantially less antagonist wear, while surface polishing exhibited less enamel wear than glazing. Because of the heterogeneity in study design, measurement methods, and outcome variables, a meta-analysis was not possible. CONCLUSIONS: Over time, the opposing enamel wear caused by polished monolithic zirconia will be either equal to or less than that of natural enamel wear. Polished monolithic zirconia also maintains lower values of enamel wear compared to metal ceramics, feldspathic porcelains, and lithium disilicate.

Effect of conventional cigarette smoking and recent heated tobacco products on CAD/CAM restorative materials.

OBJECTIVE: To determine the effects of conventional cigarette smoking (CS) and recent heated tobacco products (HTPs) on the surface roughness and color stability of different indirect restorative materials. MATERIALS AND METHODS: One hundred disc-shaped samples were constructed of three different restorative CAD/CAM materials: lithium disilicate glass-ceramic (IPS e.max CAD; Ivoclar Vivadent, Liechtenstein), zirconia (BruxZir® Zirconia, Glidewell, USA) and polyetheretherketone (BioHPP® bredent GmbH, Germany). Of the IPS e.max CAD and the Bruxzir samples, 20 samples were glazed, and 20 samples were polished, while the BioHPP samples were all polished according to the manufacturer's instructions. Fifty samples were subjected to conventional cigarette smoking (LM, Philip Morris International Inc., Egypt) (Groups: IPS e.max CAD_Glazed exposed to CS (LD_G_Cig), IPS e.max CAD_Polished exposed to CS (LD_P_Cig), Bruxzir_Glazed exposed to CS (Zr_G_Cig), Bruxzir _Polished exposed to CS (Zr_P_Cig) and BioHPP exposed to CS (PEEK_Cig) and fifty samples were exposed to heated tobacco product smoking (Heets, Russet selection, Philip Morris International Inc., Italy) (Groups: IPS e.max CAD_Glazed exposed to HTP (LD_G_HTP), IPS e.max CAD_Polished exposed to HTP (LD_P_HTP), Bruxzir_Glazed exposed to HTP (Zr_G_HTP), Bruxzir CAD_Polished exposed to HTP (Zr_P_HTP) and BioHPP exposed to HTP (PEEK_HTP).. Six hundred cigarettes/heets representing 30 days of medium smoking behavior (20 cigarettes/day) were used. Before and after exposure to smoke, the surface roughness of all the samples was measured using JITAI8101 surface roughness tester (Beijing Jitai Tech Detection Device Co., Ltd, China, and the color parameters were assessed using VITA Easyshade Advance 4.01 (VITA shade, VITA made, VITA). The data were analyzed using One-way ANOVA, paired sample t-test and independent sample t-test. The significance level was set at α < 0.05. The surface topography was evaluated by scanning electron microscopy (SEM) and analyzed using energy-dispersive X-ray (EDX) spectroscopy to determine changes in the surface chemical composition. RESULTS: Both types of smoking caused significant increases in the surface roughness of all the samples. There was a significant difference in color change between CS and HTP for all materials with different surface finish (P < 0.01) and zirconia had the greatest effect on color change (P < 0.001). In contrast, polyetheretherketone (PEEK) "BioHPP" had the least effect (P < 0.001). CONCLUSION: Exposure to different types of smoking induce changes in the surface topography and color of different esthetic restorative materials. Compared with HTP, conventional cigarette smoke has a greater effect on the surface roughness and color stability of esthetic restorative materials. The glazed surfaces showed less change in surface topography than did the polished surfaces. Zirconia showed better color stability when compared to polyetheretherketone (PEEK).

Effect of Coffee Thermocycling on Color Stability and Translucency of CAD-CAM Polychromatic High Translucent Zirconia Compared With Lithium Disilicate Glass Ceramic.

AIMS AND OBJECTIVES: To evaluate the effect of coffee thermocycling on color stability and translucency of CAD-CAM polychromatic high translucent zirconia compared with lithium disilicate glass ceramic. METHODS: Sixteen rectangular plates (14 × 16 × 1.0 mm) of two ceramic materials (IPS E.max CAD (IEC), IPS E.max ZirCAD Prime [IZP]) were prepared. Each specimen was measured for color coordinates using a spectrophotometer following 30,000 cycles of coffee thermocycling. CIELAB formula was used to determine color and translucency differences (ΔE and ΔTP). The means of ΔE and ΔTP were compared using independent samples t-test and were evaluated using their respective 50%:50% perceptibility and acceptability thresholds (PT and AT). One-way analysis of variance was performed to evaluate the translucency parameter (TP) and surface roughness (Ra) of each material. RESULTS: Mean ΔE values of IEC (4.69) and IZP (4.64) were higher than the AT (ΔE ≤ 2.7) with no significant difference found between the two groups (p = 0.202). Considering the TP, only IEC showed a statistically significant increase in TP value (p < 0.001). However, the mean ΔTP of IEC (3.25) remained within the range of acceptability (1.3 < ΔTP ≤ 4.4). CONCLUSIONS: Within the limitations of this current study, the color stability of all materials was clinically affected by coffee thermocycling. In terms of translucency, only lithium disilicate glass ceramic was influenced by coffee thermocycling. High translucent zirconia had superior translucency stability compared to lithium disilicate glass ceramic.

Effects of Different Concentrations of Carbamide Peroxide on Color, Surface Roughness, and Hardness of CAD/CAM Dental Ceramics.

OBJECTIVES: This study assessed the effects of 15% and 20% carbamide peroxide (CP) on color, surface roughness, and hardness of computer-aided design/computer-aided manufacturing (CAD/CAM) dental ceramics. MATERIALS AND METHODS: This in vitro study was conducted on 120 Vita Mark II, Celtra Duo, and Suprinity CAD/CAM ceramic specimens. The ceramic specimens in each group (n = 40) were randomly assigned to two subgroups (n = 20) for polishing and glazing, and their baseline color, surface roughness (Ra), and hardness were assessed. In each subgroup, half of the specimens were exposed to 15% CP, while the other half were exposed to 20% CP. Their color change (ΔE), surface roughness, and hardness were then measured again. Surface roughness, hardness, and color were analyzed sequentially by profilometer, Vickers hardness tester, and spectrophotometer, respectively. Data were analyzed by repeated measures ANOVA, one-way ANOVA, and post hoc Bonferroni test (α = 0.05). RESULTS: The surface roughness of all groups significantly increased after bleaching treatment (p < 0.05). Surface hardness of all groups decreased after bleaching treatment, but this reduction was only significant in Vita Mark II subgroups (glazed, polished, 15%, and 20% CP). The ΔE was not clinically and visually perceivable in any group. CONCLUSION: The present results revealed that concentration of CP and type of surface treatment affected the surface properties of CAD/CAM ceramics. Type of surface treatment only affected the surface hardness of Vita Mark II ceramics (p < 0.05). Concentration of CP had a significant effect only on polished Vita Mark II.

Development of Bioactive Hybrid Poly(lactic acid)/Poly(methyl methacrylate) (PLA/PMMA) Electrospun Fibers Functionalized with Bioglass Nanoparticles for Bone Tissue Engineering Applications.

Hybrid scaffolds that are based on PLA and PLA/PMMA with 75/25, 50/50, and 25/75 weight ratios and functionalized with 10 wt.% of bioglass nanoparticles (n-BG) were developed using an electrospinning technique with a chloroform/dimethylformamide mixture in a 9:1 ratio for bone tissue engineering applications. Neat PLA and PLA/PMMA hybrid scaffolds were developed successfully through a (CF/DMF) solvent system, obtaining a random fiber deposition that generated a porous structure with pore interconnectivity. However, with the solvent system used, it was not possible to generate fibers in the case of the neat PMMA sample. With the increase in the amount of PMMA in PLA/PMMA ratios, the fiber diameter of hybrid scaffolds decreases, and the defects (beads) in the fiber structure increase; these beads are associated with a nanoparticle agglomeration, that could be related to a low interaction between n-BG and the polymer matrix. The Young's modulus of PLA/PMMA/n-BG decreases by 34 and 80%, indicating more flexible behavior compared to neat PLA. The PLA/PMMA/n-BG scaffolds showed a bioactive property related to the presence of hydroxyapatite crystals in the fiber surface after 28 days of immersion in a Simulated Body Fluids solution (SBF). In addition, the hydrolytic degradation process of PLA/PMMA/n-BG, analyzed after 35 days of immersion in a phosphate-buffered saline solution (PBS), was less than that of the pure PLA. The in vitro analysis using an HBOF-1.19 cell line indicated that the PLA/PMMA/n-BG scaffold showed good cell viability and was able to promote cell proliferation after 7 days. On the other hand, the in vivo biocompatibility evaluated via a subdermal model in BALC male mice corroborated the good behavior of the scaffolds in avoiding the generation of a cytotoxic effect and being able to enhance the healing process, suggesting that the materials are suitable for potential applications in tissue engineering.

[Types and colors of 1 374 chair-side CAD/CAM all-ceramic restorations].

PURPOSE: To analyse the types of chairside CAD/CAM all-ceramic restorations and the color range of all-ceramic materials used so as to provide reference for the application of clinical chairside all-ceramic restoration and the color selection of all-ceramic materials. METHODS: IPS e.max CAD prostheses and related data were collected from January 2021 to December 2021 from the Department of Prosthodontics, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine. The number and type of restorations and the color of materials were investigated and analyzed by descriptive statistics. RESULTS: A total of 1 374 restorations were included, of which 624 were crown restorations, accounting for 45.41% of the total restorations. 516 cases were veneer, accounting for 37.55%; 219 were inlays, accounting for 15.94%; fixed bridges were all adhesive bridges, with the least number with only 15 cases, accounting for 1.09%. In terms of the selection of restoration materials, the use rate of low-transparent(LT) ceramic blocks was significantly higher than that of other transparent ceramic blocks. A was the most frequently used ceramic color. The most frequently used porcelain blocks for veneers were LTA2 and LTA1; for inlay were LTA3; for crowns were LTA2 and LTA3. The blocks used in the fixed bridges were all LT, and A3 color was the majority. CONCLUSIONS: Chairside CAD/CAM all-ceramic prostheses made of IPS e.max CAD materials have been widely used in clinical practice. The types of prostheses include veneer, inset, crown and fixed bridge. The most commonly used IPS e.max CAD blocks are LTA2, LTA3 and LTA1. These findings have certain guiding significance for the clinical restoration decision and the reserve of porcelain blocks in primary hospitals.

Tailoring zirconia surface topography via femtosecond laser-induced nanoscale features: effects on osteoblast cells and antibacterial properties.

The performance and long-term durability of dental implants hinge on the quality of bone integration and their resistance to bacteria. This research aims to introduce a surface modification strategy for zirconia implants utilizing femtosecond laser ablation techniques, exploring their impact on osteoblast cell behavior and bacterial performance, as well as the integral factors influencing the soft tissue quality surrounding dental implants. Ultrafast lasers were employed to craft nanoscale groove geometries on zirconia surfaces, with thorough analyses conducted using x-ray diffraction, scanning electron microscopy, atomic force microscopy, and water contact angle measurements. The study evaluated the response of human fetal osteoblastic cell lines to textured zirconia ceramics by assessing alkaline phosphatase activity, collagen I, and interleukin 1ßsecretion over a 7 day period. Additionally, the antibacterial behavior of the textured surfaces was investigated usingFusobacterium nucleatum, a common culprit in infections associated with dental implants. Ciprofloxacin (CIP), a widely used antibacterial antibiotic, was loaded onto zirconia ceramic surfaces. The results of this study unveiled a substantial reduction in bacterial adhesion on textured zirconia surfaces. The fine biocompatibility of these surfaces was confirmed through the MTT assay and observations of cell morphology. Moreover, the human fetal osteoblastic cell line exhibited extensive spreading and secreted elevated levels of collagen I and interleukin 1ßin the modified samples. Drug release evaluations demonstrated sustained CIP release through a diffusion mechanism, showcasing excellent antibacterial activity against pathogenic bacteria, includingStreptococcus mutans, Pseudomonas aeruginosa, andEscherichia coli.

Gamma-ray shielding characteristics of concrete containing different percentage of ceramics for different energies.

To shield people from dangerous gamma radiation, it is imperative to fabricate inexpensive and environmentally friendly materials. In the present work, suitability of concrete with various % concentrations of ceramics as gamma-ray shielding material has been studied. In this regard, concrete mixture using M-sand and cement with ceramic as filler in different concentrations has been prepared. The mass attenuation coefficients of the prepared samples were measured for different concentrations of ceramics such as 15, 30, 45 and 60%. The mass attenuation coefficients, half value layer (HVL) and tenth vale layer (TVL) of the prepared samples were determined using gamma-ray spectrometer with NaI(Tl) detector at 511, 661.6, 1173, 1332 keV gamma energies. Experimentally obtained mass attenuation coefficients varied from 0.080 to 0.090, 0.074 to 0.086, 0.056 to 0.072 and 0.054 to 0.055 cm2 g-1 at 511, 662, 1173 and 1332 keV, respectively. Therefore concrete mixture with ceramics filler could be a promising shielding material than the bare concrete.

Marginal integrity of prototype bioactive glass-doped resin composites in class II cavities.

OBJECTIVES: This in vitro study examined the marginal integrity of experimental composite materials doped with bioactive glass (BG). MATERIALS AND METHODS: Class-II MOD cavities were prepared and restored with one of the following composite materials: a commercial composite material as a reference (Filtek Supreme XTE), an experimental composite doped with BG 45S5 (C-20), and an experimental composite doped with a fluoride-containing BG (F-20). Six experimental groups (n = 8) were used, as each of the three composites was applied with (+) or without (-) a universal adhesive (Adper Scotchbond Multipurpose). All specimens were subjected to thermocycling (10,000 x, 5-55 °C) and then additionally stored in artificial saliva for eight weeks. Scanning electron micrographs of the mesial and the distal box were taken at three time points (initial, after thermocycling, and after eight weeks of storage in artificial saliva). The margins were classified as "continuous" and "non-continuous" and the percentage of continuous margins (PCM) was statistically analyzed (α = 0.05). RESULTS: In most experimental groups, thermocycling led to a significant decrease in PCM, while the additional 8-week aging had no significant effect. F-20 + performed significantly better (p = 0.005) after 8 weeks storage in artificial saliva than the reference material with adhesive, while no statistically significant differences were observed at the other two time points. C-20 + exhibited significantly better PCM than the reference material with adhesive after thermocycling (p = 0.026) and after 8 weeks (p = 0.003). CONCLUSIONS: Overall, the experimental composites with BG showed at least as good marginal adaptation as the commercial reference, with an indication of possible re-sealing of marginal gaps. CLINICAL RELEVANCE: Maintaining or improving the marginal integrity of composite restorations is important to prevent microleakage and its likely consequences such as pulp irritation and secondary caries.

Regenerative Potential of Dental Pulp Stem Cells in Response to a Bioceramic Dental Sealer and Photobiomodulation: An In Vitro Study.

AIMS: This study aims to assess the synergistic effect of utilizing a bioceramic sealer, NeoPutty, with photobiomodulation (PBM) on dental pulp stem cells (DPSCs) for odontogenesis. MATERIALS AND METHODS: Dental pulp stem cells were collected from 10 premolars extracted from healthy individuals. Dental pulp stem cells were characterized using an inverted-phase microscope to detect cell shape and flow cytometry to detect stem cell-specific surface antigens. Three experimental groups were examined: the NP group, the PBM group, and the combined NP and PBM group. A 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) experiment was conducted to assess the viability of DPSCs. The odontogenic differentiation potential was analyzed using Alizarin red staining, RT-qPCR analysis of odontogenic genes DMP-1, DSPP, and alkaline phosphatase (ALP), and western blot analysis for detecting BMP-2 and RUNX-2 protein expression. An analysis of variance (ANOVA) followed by a post hoc t-test was employed to examine and compare the mean values of the results. RESULTS: The study showed a notable rise in cell viability when NP and PBM were used together. Odontogenic gene expression and the protein expression of BMP-2 and RUNX-2 were notably increased in the combined group. The combined effect of NeoPutty and PBM was significant in enhancing the odontogenic differentiation capability of DPSCs. CONCLUSION: The synergistic effect of NeoPutty and PBM produced the most positive effect on the cytocompatibility and odontogenic differentiation potential of DPSCs. CLINICAL SIGNIFICANCE: Creating innovative regenerative treatments to efficiently and durably repair injured dental tissues. How to cite this article: Alshawkani HA, Mansy M, Al Ankily M, et al. Regenerative Potential of Dental Pulp Stem Cells in Response to a Bioceramic Dental Sealer and Photobiomodulation: An In Vitro Study. J Contemp Dent Pract 2024;25(4):313-319.

Cerium doping of 45S5 bioactive glass improves redox potential and cellular bioactivity.

45S5 Bioglass (BG) is composed of a glass network with silicate based on the component and can be doped with various therapeutic ions for the enhancement of hard tissue therapy. Nanoceria (CeO2) has been shown to indicate redox reaction and enhance the biological response. However, few studies focus on the proportion of CeO2-doped and its effect on the cellular bioactivity of CeO2-doped BG (CBG). In this study, we synthesized the CBG series with increasing amounts of doping CeO2 ranging (1 to 12) wt.%. The synthesized CBG series examined the characterization, mineralization capacity, and cellular activity against BG. Our results showed that the CBG series exhibited a glass structure and indicated the redox states between Ce3+ and Ce4+, thus they showed the antioxidant activity by characterization of Ce. The CBG series had a stable glass network structure similar to BG, which showed the preservation of bioactivity by exhibiting mineralization on the surface. In terms of biological response, although the CBG series showed the proliferative activity of pre-osteoblastic cells similar to BG, the CBG series augmented not only the alkaline phosphatase activity but also the osteogenic marker in the mRNA level. As stimulated the osteogenic activity, the CBG series improved the biomineralization. In conclusion, the CBG series might have a potential application for hard tissue therapeutic purposes.

Osteointegration of functionalised high-performance oxide ceramics: imaging from micro-computed tomography.

BACKGROUND: This study evaluated the osseointegration potential of functionalised high-performance oxide ceramics (HPOC) in isolation or coated with BMP-2 or RGD peptides in 36 New Zeeland female rabbits using micro-computed tomography (micro CT). The primary outcomes of interest were to assess the amount of ossification evaluating the improvement in the bone volume/ total volume (BV/TV) ratio and trabecular thickness at 6 and 12 weeks. The second outcome of interest was to investigate possible differences in osteointegration between the functionalised silanised HPOC in isolation or coated with Bone Morphogenetic Protein 2 (BMP-2) or RGD peptides. METHODS: 36 adult female New Zealand white rabbits with a minimum weight of three kg were used. One-third of HPOCs were functionalised with silicon suboxide (SiOx), a third with BMP-2 (sHPOC-BMP2), and another third with RGD (sHPOC-RGD). All samples were scanned with a high-resolution micro CT (U-CTHR, MILabs B.V., Houten, The Netherlands) with a reconstructed voxel resolution of 10 µm. MicroCT scans were reconstructed in three planes and processed using Imalytics Preclinical version 2.1 (Gremse-IT GmbH, Aachen, Germany) software. The total volume (TV), bone volume (BV) and ratio BV/TV were calculated within the coating area. RESULTS: BV/TV increased significantly from 6 to 12 weeks in all HPOCs: silanised (P = 0.01), BMP-2 (P < 0.0001), and RGD (P < 0.0001) groups. At 12 weeks, the BMP-2 groups demonstrated greater ossification in the RGD (P < 0.0001) and silanised (P = 0.008) groups. Trabecular thickness increased significantly from 6 to 12 weeks (P < 0.0001). At 12 weeks, BMP-2 promoted greater trabecular thickness compared to the silanised group (P = 0.07), although no difference was found with the RGD (P = 0.1) group. CONCLUSION: Sinalised HPOC in isolation or functionalised with BMP-2 or RGD promotes in vivo osteointegration. The sinalised HOPC functionalised with BMP-2 demonstrated the greatest osseointegration.

Emerging trends and clinical recommendations for zirconia ceramic crowns: a concise review.

Introduction A little over ten years ago, zirconia crowns made their debut in the field of dentistry. Despite early problems with the chipping of veneering porcelain, clinical studies have demonstrated excellent performance. It is essential for a ceramic crown to have good aesthetic qualities, in addition to having good mechanical characteristics. The exceptional mechanical qualities of zirconia crowns and the simplicity with which they may be machined, employing computer-aided design and computer-aided manufacturing schemes, are primarily responsible for the widespread use of these materials in clinical settings. New ceramic-based materials, including monolithic zirconia, zirconia-containing lithium disilicate ceramics, and graded glass/zirconia/glass, have recently been launched in the field of dentistry. These newly discovered zirconia crown materials stem from varied technological approaches, each likely to lead to additional clinical advancements. At this point, it seems imperative to offer a concentrated report on the newer developments, along with essential clinical recommendations for best clinical outcomes with zirconia crowns.Types of studies This review article is a consolidation of several case studies, cohort studies and systematic reviews, as well as experimental and observational randomised control trials and other peer-reviewed articles.Results On reviewing, a concise list of clinical recommendations is generated, demonstrating that monolithic zirconia offers some clinical advantages over veneered zirconia crowns.Conclusion This review article discloses various clinical revelations and in-office recommendations for favourable usage of zirconia ceramic crowns that can lead to better patient outcomes and long-term clinical success rates.

Methodological approaches in graded dental ceramics: a scoping review protocol.

OBJECTIVES: This review will map the various methodological approaches used in graded dental ceramics and distinguish their material characteristics and properties. The aim is to identify gaps in the development and application of grading in dental ceramic systems. INTRODUCTION: The advantage of functionally graded materials is the absence of the weakest link, with no distinct boundaries, thereby eliminating the possibility of stress concentrations at the interfaces. Functionally graded materials are well established in nature, such as in human teeth, bone, and the bio-tissues of plants and animals. This concept has also been explored in dental ceramics to enhance fatigue resistance and strength. INCLUSION CRITERIA: This review will include observational studies and interventional studies, such as in vitro and experimental studies, on functionally graded dental ceramic systems. Studies that use finite element analysis to evaluate stress distributions, and studies on the mechanical performance of graded dental ceramics, irrespective of the type of ceramic material, design, or thickness of graded layers, will be considered. METHOD: The review will follow the JBI methodology for scoping reviews and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews. MEDLINE (PubMed), Scopus, ProQuest Dissertations and Theses (EBSCOhost), Cochrane CENTRAL, and Google Scholar will be searched for English language studies. The search strategy will be based on MeSH terms and free-text specific terms, and will be adapted for each database. Two independent reviewers will screen titles and abstracts, and extract data from selected sources. The data extracted from the selected studies will be analyzed and presented in the form of tables and figures. REVIEW REGISTRATION: Open Science Framework: https://osf.io/ahsp7.

Composite bone graft of CaO-MgO-SiO2 glass-ceramics and CaSO4 ceramics for boosting bone formation rate.

This study develops a composite bone graft of CaO-MgO-SiO2 glass-ceramic and CaSO4 [abbreviated as (CMS)3-x(CS)x] via the sponge replication technique with weight fractions of x = 0, 1, 1.5, 2, and 3. The (CMS)1.5(CS)1.5 composite displays a superior degradability and, a suitable compressive strength of ∼3 MPa, and excellent cell proliferation and differentiation. The in vivo rat femur test in the hybrid-pore (CMS)1.5(CS)1.5 composite granules achieves a higher rate of bone formation, which is ∼2.7 times better than that of the commercial HAP/ß-TCP at 12 weeks. Improved expressions of osteocyte and mature osteocyte marker genes, namely (Spp1, Dmp1, and Fgf23), were observed in the (CMS)1.5(CS)1.5 group, indicating a faster differentiation into mature bone tissue. The ions release of (CMS)1.5(CS)1.5 through the ERK1/2 signaling pathway promotes osteogenic differentiation. The high bone generation rate can be attributed to faster active ions release and modified surface topography. This work highlights an excellent bone graft candidate for clinical applications in orthopedic surgery.

Chemical fractionation and mobility of Cd, Mn, Ni, and Pb in farmland soils near a ceramics company.

Soil contamination due to industrial activity in ceramics production is of concern because of the risk of heavy metal pollution. Successive extraction was used to measure and identify the concentrations of Cd, Mn, Ni, and Pb in farming soils near a ceramics company in Nigeria. Furthermore, soil pH and particle size analyses were determined. The concentration of Pb was the highest, followed by that of Ni, Mn, and Cd (lowest), and the mean level of Cd exceeded the regulatory allowed limit of 1.4 mg kg-1. The order of the metals' mobility factors was as follows: Cd > Mn > Ni, Pb. While the Fe-Mn oxide phase had 37% (Mn) and 20 to 83% (Ni), the residual fraction had approximately 30% (Cd) and 19 to 50% (Pb). Soil pollution evaluation was performed using enrichment factor (EF), contamination factor (CF), pollution load index (PLI), and geoaccumulation index (Igeo). Values of EF indicated significant enrichment for all metals, as the EF mean values for Cd, Ni, and Pb in soil were > 1.5. Total EF is of the order Cd > Pb > Ni > Mn. CF results revealed moderate to very high contamination (CF < 1: 3 ≤ CF ≥ 6). Similarly, the PLI indicated moderately to severely polluted soil. The order is 100 m > 200 m > 300 m > 400 m. The Igeo ranged from 1.46 to 2.76 (Cd), 0.07 to 1.62 (Ni), and 0.05 to 2.81 (Pb). The PCA, CA, and EF analyses suggest that the metals are a consequence of anthropogenic activities.

Effect of different design and surface treatment on the load-to-failure of ceramic repaired with composite.

Glass ceramics are widely used to manufacture esthetic veneers, inlays, onlays, and crowns. Although the clinical survival rates ofglass-ceramic restorations arefavorable,fractures or chips are common. Certain cases can be repaired with direct composite. AIM: The aim of this study was to investigate the interaction effect of different designs and surface treatments on the load-to-failure of lithium disilicate glass-ceramic repaired with nanofilled composite. MATERIALS AND METHOD: Lithium-disilicate glass-ceramic slabs (IPS e.max Press, Ivoclar Vivadent) with three different designs of the top surface (flat, single plateau, or doubleplateau) (n=U) received 'no treatment', '5% HF etching', or "AI2O3 sandblasting". HF-etched and sandblasted slabs also received silane and universal one-step adhesive application. All slabs were incrementally repaired with nanofilled composite (Filtek Z350, 3M ESPE) up to6 mm above the highest ceramic top plateau. Specimens were stored in artificial saliva at 37 °C for 21 days and then subjected to 1,000 thermocycles between 5 and 55 °C. The interface composite-ceramic of each specimen was tensile tested until failure in a universal testing machine and the mode of failure was determined under a stereomicroscope. The ceramic surface morphology of one representative tested specimen from each subgroup (design/surface treatment) was observed through scanning electron microscopy (SEM). RESULTS: Regardless of ceramic design, the absence of surface treatment resulted in significantly lower load-to-failure values. No significant differences in load-to-failure values were observed between HF-etched and sandblasted specimens for the flat design; however, HF etching resulted in significantly higher load-to-failure values than sandblasting for both single plateau and double plateau designs. The majority (60%) of HF-etched specimens with single plateau or double plateau presented mixed failures. SEM photomicrographs showed that HF-etched specimens had smoother surfaces than sandblasted specimens. CONCLUSION: The surface treatment of a defective lithium disilicate glass-ceramic restoration has more influence than its macroscopic design on the retention of the composite repair. HF etching seems to provide higher bond strength to the composite repair.

Embora fraturas e lascamento de restauragoes vitrocerámicas sejam comuns, alguns casos podem ser reparados com compósito direto. OBJETIVO: investigar o efeito da interagao de diferentes formas e tratamentos de superficie na carga de ruptura de uma vitrocerámica reforgada com dissilicato de litio reparada com compósito nanoparticulado. MATERIAIS E MÉTODOS: A superficie superior de espécimes de vitroceramica (IPS e.max Press, Ivoclar Vivadent) foi preparada com tres formas (plana, plato único, ou duplo) e recebeu (n=11): 'nenhum tratamento', 'condicionamento com ácido hidrofluoridrico 5%', ou 'jateamento com AfOf. Ambos espécimes condicionados e jateados receberam silano e adesivo universal. Todos os espécimes foram reparados incrementalmente com compósito (Filtek Z350, 3M ESPE) até6 mm acima do plato cerámico mais alto, armazenados em saliva artificial á 37 °C por 21 dias, e submetidos á 1.000 termociclos (5 e 55 °C). A interface compósito-cerámica de cada amostra foi testada á tragao até sua falha em máquina universal e o modo de falha foi determinado com estereomicroscópio. A morfologia da superficie de uma amostra representativa de forma/tratamento de superficie foi observada através de microscopia eletronica de varredura (MEV). RESULTADOS: Independentemente da forma ceramica, a ausencia de tratamento superficial resultou em valores de carga de ruptura significativamente menores. Nao foi observada differenga significativa entre os espécimes planos condicionados ou jateados; no entanto, o condicionamento resultou em valores significativamente maiores que o jateamento para espécimes com plato único e duplo. A maioria (60%) dos espécimes condicionados e com plato único ou duplo apresentou falhas mistas. Imagens SEM demonstraram rugosidade superficial mais regular dos espécimes condicionados que os jateados. CONCLUSÕES: O tratamento superficial de uma restauragao defeituosa de vitrocerámica reforgada por dissilicato de litio tem maior influencia na retengao do reparo de compósito do que sua forma macroscópica; ainda, o condicionamento com ácido hidrofluoridrico parece proporcionar maior resistencia de uniao ao reparo com compósito.

Resistance of CAD/CAM composite resin and ceramic occlusal veneers to fatigue and fracture in worn posterior teeth: A systematic review.

Severe tooth wear is related to substantial loss of tooth structure, with dentin exposure and significant loss (≥1/3) of the clinical crown. The objective of this systematic review was to summarize and analyze the scientific evidence regarding the mechanical performance of computer-aided design/computer-aided manufacturing (CAD/CAM) composite resin and CAD/CAM lithium disilicate ceramic occlusal veneers, in terms of fatigue and fracture resistance, on severely worn posterior teeth. Currently, occlusal veneers are an alternative for treating worn posterior teeth. Although scientific evidence demonstrates the good performance of lithium disilicate occlusal veneers, there are less brittle materials with a modulus of elasticity more similar to dentin than ceramics, such as resin CAD/CAM blocks. Therefore, it is important to identify which type of material is best for restoring teeth with occlusal wear defects and which material can provide better clinical performance. This review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A comprehensive search of the PubMed, Embase, Web of Science, Scopus, Cochrane, OpenGrey, Redalyc, DSpace, and Grey Literature Report databases was conducted and supplemented by a manual search, with no time or language limitations, until January 2022. We aimed to identify studies evaluating the fatigue and fracture resistance of CAD/CAM composite resin and ceramic occlusal veneers. The quality of the full-text articles was evaluated according to the modified Consolidated Standards of Reporting Trials (CONSORT) criteria for in vitro studies, and 400 articles were initially identified. After removing duplicates and applying the selection criteria, 6 studies were included in the review. The results demonstrated that the mechanical performance of CAD/CAM composite resin occlusal veneers is comparable to that of CAD/CAM lithium disilicate occlusal veneers in terms of fatigue and fracture resistance.