Dental implant and abutment in PEEK: stress assessment in single crown retainers on anterior region.

OBJECTIVE: Stress distribution assessment by finite elements analysis in poly(etheretherketone) (PEEK) implant and abutment as retainers of single crowns in the anterior region. MATERIALS AND METHODS: Five 3D models were created, varying implant/abutment manufacturing materials: titanium (Ti), zirconia (Zr), pure PEEK (PEEKp), carbon fiber-reinforced PEEK (PEEKc), glass fiber-reinforced PEEK (PEEKg). A 50 N load was applied 30o off-axis at the incisal edge of the upper central incisor. The Von Mises stress (σvM) was evaluated on abutment, implant/screw, and minimum principal stress (σmin) and maximum shear stress (τmax) for cortical and cancellous bone. RESULTS: The abutment σvM lowest stress was observed in PEEKp group, being 70% lower than Ti and 74% than Zr. On the implant, PEEKp reduced 68% compared to Ti and a 71% to Zr. In the abutment screws, an increase of at least 33% was found in PEEKc compared to Ti, and of at least 81% to Zr. For cortical bone, the highest τmax values were in the PEEKp group, and a slight increase in stress was observed compared to all PEEK groups with Ti and Zr. For σmin, the highest stress was found in the PEEKc. Stress increased at least 7% in cancellous bone for all PEEK groups. CONCLUSION: Abutments and implants made by PEEKc concentrate less σvM stress, transmitting greater stress to the cortical and medullary bone. CLINICAL RELEVANCE: The best stress distribution in PEEKc components may contribute to decreased stress shielding; in vitro and in vivo research is recommended to investigate this.

Evaluation and assessment of the wettabilty and water contact angle of modified poly methyl methacrylate denture base materials against PEEK in cast partial denture framework: an in vitro study.

INTRODUCTION: The prevalence of adults with partially dental arches is expected to be more than imagined and patients requiring replacement of missing teeth are slowly increasing in number too. Removable partial dentures are known to provide for substantial replacement for the missing teeth with also added advantages when compared to fixed or implant prosthesis, mainly in elderly patients. Denture base material performance and durability are greatly influenced by wettability and water contact angle. In the case of dentures; adequate moisture distribution is necessary to ensure excellent wettability which has an influence on comfort and oral health. The purpose of conducting this study was to find out whether the advancements made using PEEK (Polyether ether ketone) would prove to be more beneficial than the current upgrades in the current material spectrum. MATERIALS AND METHODS: This study was performed under in vitro conditions. All the fabrication and processing was done only by one operator. The materials used were divided into three groups each comprising 20 samples. Group A was modified polymethylmethacrylate (Bredent Polyan), Group B was polyoxymethylene acetal resin (Biodentaplast) and Group C was PEEK. An Ossila Goniometer was used to measure the contact angle. The three types of liquids used for the testing included distilled water, natural saliva and mouth wetting solution (Wet Mouth Liquid, ICPA India). Human saliva was collected from an individual with no medical conditions and normal salivary secretion. RESULTS: The data was analyzed using One-way ANOVA test and a pairwise comparison using the Post Hoc Tukey's Honest Significant Difference. Table 1 consists of the mean water contact angles of the denture base materials and mean contact angles of various denture base materials. In saliva, mouth wetting solution and distilled water, the highest mean and least mean contact angle was seen in Polyan and Biodentaplast respectively. A signicant difference was seen between PEEK and Polyan and Biodentaplast and Polyan on further comparison. CONCLUSION: From the resources and the materials at our disposal, it could be concluded that Polyan, Biodentaplast and PEEK and could be used as viable options in cast partial denture framework.

Acute Ingestion of a Ketone Monoester without Co-ingestion of Carbohydrate Improves Running Economy in Male Endurance Runners.

PURPOSE: Acute ingestion of a ketone monoester, with and without co-ingestion of carbohydrate, was investigated for effects on running economy (RE), time to exhaustion (TTE), and other related indices of endurance running performance. METHODS: Using a three condition, placebo-controlled, randomized crossover design, 11 male middle- and long-distance runners ran at five submaximal speeds (10-14 km·h -1 ) on a motorized treadmill for 8 min each, immediately followed by a ramp test to volitional exhaustion. Participants consumed either a 10% carbohydrate solution (CHO), a 10% carbohydrate solution with 750 mg·kg -1 body mass of an ( R )-3-hydroxybutyl ( R )-3-hydroxybutyrate ketone monoester (CHO + KE), or 750 mg·kg -1 body mass of the ketone monoester in flavored water (KE) before (two-thirds of the dose) and during (one-third of the dose) exercise. RESULTS: ß-hydroxybutyrate concentration averaged 1.8 ± 0.3 and 2.1 ± 0.3 mM during exercise in CHO + KE and KE, respectively. RE was lower at each submaximal running speed (effect size = 0.48-0.98) by an average of 4.1% in KE compared with CHO, but not between CHO + KE and CHO. TTE did not differ between CHO (369 ± 116 s), CHO + KE (342 ± 99 s), or KE (333 ± 106 s) ( P = 0.093). CONCLUSIONS: Acute ingestion of a ketone monoester without carbohydrate, but not when coingested with carbohydrate, improved RE in middle- and long-distance runners at a range of submaximal running speeds and did not alter TTE in a short-duration ramp test to volitional exhaustion. Further investigation is required to examine if these differences translate into positive performance outcomes over longer durations of exercise.

Composition analysis and health risk assessment of the hazardous compounds in cooking fumes emitted from heated soybean oils with different refining levels.

The cooking fumes generated from thermal cooking oils contains various of hazardous components and shows deleterious health effects. The edible oil refining is designed to improve the oil quality and safety. While, there remains unknown about the connections between the characteristics and health risks of the cooking fumes and oils with different refining levels. In this study, the hazardous compounds, including aldehydes, ketones, polycyclic aromatic hydrocarbons (PAHs), and particulate matter (PM) in the fumes emitted from heated soybean oils with different refining levels were characterized, and their health risks were assessed. Results demonstrated that the concentration range of aldehydes and ketones (from 328.06 ± 24.64 to 796.52 ± 29.67 µg/m3), PAHs (from 4.39 ± 0.19 to 7.86 ± 0.51 µg/m3), and PM (from 0.36 ± 0.14 to 5.08 ± 0.15 mg/m3) varied among soybean oil with different refining levels, respectively. The neutralized oil showed the highest concentration of aldehydes and ketones, whereas the refined oil showed the lowest. The highest concentration levels of PAHs and PM were observed in fumes emitted from crude oil. A highly significant (p < 0.001) positive correlation between the acid value of cooking oil and the concentrations of PM was found, suggesting that removing free fatty acids is critical for mitigating PM concentration in cooking fumes. Additionally, the incremental lifetime cancer risk (ILCR) values of PAHs and aldehydes were 5.60 × 10-4 to 8.66 × 10-5 and 5.60 × 10-4 to 8.66 × 10-5, respectively, which were substantially higher than the acceptable levels (1.0 × 10-6) established by US EPA. The present study quantifies the impact of edible oil refining on hazardous compound emissions and provides a theoretical basis for controlling the health risks of cooking fumes via precise edible oil processing.

Identification of geographical origins of soybean pastes using headspace gas chromatography-mass spectrometry by selecting sample-descriptive components with an Incremental Association Markov Blanket.

The identification of geographical origins of soybean pastes using headspace gas chromatography-mass spectrometry was attempted in this study. Since soybean paste was odor-rich, 36 components were identified in the imported and domestic soybean samples. t-Test, variable importance in projection (VIP), and Incremental Association Markov Blanket (IAMB) were employed to select proper components that could effectively discriminate the two sample groups. The discrimination accuracies were below 87.3 % when all 36 components were fed for either LDA, k-NN, or SVM. When the five t-test-selected components or six VIP score-selected components were employed, the accuracies improved to 95.2-96.2 %. The IAMB selected three different components were 3-methylbutanal, 4-methylnonane, and 2,3-pentanedione, and the correlations among their peak areas were not significant. This suggests that these three components were independently relevant for the discrimination. The accuracy obtained using these three components was superior, 97.7 %, as undescriptive and/or redundant components for the discrimination were excluded.

Effects of ketone bodies on energy expenditure, substrate utilization, and energy intake in humans.

The potential of ketogenic approaches to regulate energy balance has recently gained attention since ketones may influence both energy expenditure and energy intake. In this narrative review, we summarized the most relevant evidence about the role of ketosis on energy expenditure, substrate utilization, and energy intake in humans. We considered different strategies to induce ketosis, such as fasting, dietary manipulation, and exogenous ketone sources. In general, ketosis does not have a major influence on energy expenditure but promotes a shift in substrate utilization towards ketone body oxidation. The strategies to induce ketosis by reduction of dietary carbohydrate availability (e.g., ketogenic diets) do not independently influence energy intake, being thus equally effective for weight loss as diets with higher carbohydrate content. In contrast, the intake of medium-chain triglycerides and ketone esters induces ketosis and appears to increase energy expenditure and reduce energy intake in the context of high carbohydrate availability. These latter strategies lead to slightly enhanced weight loss. Unfortunately, distinguishing the effects of the various ketogenic strategies per se from the effects of other physiological responses is not possible with the available human data. Highly controlled, inpatient studies using targeted strategies to isolate the independent effects of ketones are required to adequately address this knowledge gap.

Prevalence, Cost, and Burden of Diabetic Ketoacidosis.

Diabetic ketoacidosis (DKA) is a life-threatening complication, which is most common in individuals with type 1 diabetes (T1D) and is a significant risk for morbidity and mortality, and it is an economic burden on individuals, health care systems, and payers. Younger children, minority ethnic groups, and those with limited insurance are at the greatest risk for presentation of DKA at T1D diagnosis. Although monitoring ketone levels is an essential part of acute illness management and for both early detection and prevention of a DKA episode, studies have reported poor adherence to ketone monitoring. Ketone monitoring is particularly important for patients treated with sodium glucose cotransporter 2 inhibitor (SGLT2i) medications, in which DKA can present with only moderately elevated glucose levels, referred to as euglycemic DKA (euDKA). A majority of people with T1D and many with type 2 diabetes (T2D), particularly those using insulin therapy, are using continuous glucose monitoring (CGM) as their preferred method for measurement and management of glycemia. These devices provide a continuous stream of glucose data that enables users to take immediate action to mitigate and/or prevent severe hyperglycemic or hypoglycemic events. An international consensus of leading diabetes experts has recommended the development of continuous ketone monitoring systems, ideally a system that combines CGM technology with measurement of 3-ß-OHB into a single sensor. In this narrative review of current literature, we report on the prevalence and burden of DKA, examine challenges to detecting and diagnosing this condition, and discuss a new monitoring option for DKA prevention.

Cost-utility Analysis of Anterior Cervical Discectomy and Fusion for Cervical Spondylosis Patients Comparing Polyetheretherketone Versus Tricortical Iliac Crest Bone Graft.

STUDY DESIGN: Prospective cohort study. OBJECTIVES: To perform a cost-utility analysis and to investigate the clinical outcomes and patient's quality of life after anterior cervical discectomy and fusion (ACDF) to treat cervical spondylosis compared between fusion with polyetheretherketone (PEEK) and fusion with tricortical iliac bone graft (IBG) in Thailand. SUMMARY OF BACKGROUND DATA: ACDF is one of the standard treatments for cervical spondylosis. The fusion material options include PEEK and tricortical IBG. No previous studies have compared the cost-utility between these 2 fusion material options. PATIENTS AND METHODS: Patients with cervical spondylosis who were scheduled for ACDF at Siriraj Hospital (Bangkok, Thailand) during 2019-2020 were prospectively enrolled. Patients were allocated to the PEEK or IBG fusion material group according to the patient's choice of fusion material. EuroQol-5 dimensions 5 levels and relevant costs were collected during the operative and postoperative periods. A cost-utility analysis was performed using a societal perspective. All costs were converted to 2020 United States dollars (USD), and a 3% discount rate was used. The outcome was expressed as the incremental cost-effectiveness ratio. RESULTS: Thirty-six patients (18 ACDF-PEEK and 18 ACDF-IBG) were enrolled. Except for Nurick grading, there was no significant difference in patient baseline characteristics between groups. The average utility at 1 year after ACDF-PEEK and ACDF-IBG were 0.939 ± 0.061 and 0.798 ± 0.081, respectively ( P < 0.001). The total lifetime cost of ACDF-PEEK and ACDF-IBG was 83,572 USD and 73,329 USD, respectively. The incremental cost-effectiveness ratio of ACDF-PEEK when compared with that of ACDF-IBG showed a gain of 4468.52 USD/quality-adjusted life-years, which is considered cost-effective at the Thailand willingness-to-pay threshold of 5115 USD/quality-adjusted life-year gained. CONCLUSIONS: ACDF-PEEK was found to be more cost-effective than ACDF-IBG for treating cervical spondylosis in Thailand. LEVEL OF EVIDENCE: Level II.

Graft subsidence and reoperation after lateral lumbar interbody fusion: a propensity score-matched and cost analysis of polyetheretherketone versus 3D-printed porous titanium interbodies.

OBJECTIVE: Lumbar interbody cage subsidence has a multifactorial etiology. Cage material, although well studied after transforaminal lumbar interbody fusion, has not been investigated as a contributing factor to subsidence after lateral lumbar interbody fusion (LLIF). In this study the authors compared rates of subsidence and reoperation after LLIF between polyetheretherketone (PEEK) and 3D-printed porous titanium (pTi) in an institutional propensity score-matched and cost analysis. METHODS: This is a retrospective observational cohort analysis of adult patients who underwent LLIF with pTi versus PEEK between 2016 and 2020. Demographic, clinical, and radiographic characteristics were collected. Propensity scores were calculated and 1:1 matching without replacement of surgically treated levels was performed. The primary outcome of interest was subsidence. The Marchi subsidence grade was determined at the time of last follow-up. Chi-square or Fisher's exact tests were used to compare subsidence and reoperation rates between lumbar levels treated with PEEK versus pTi. Modeling and cost analysis were performed using TreeAge Pro Healthcare. RESULTS: The authors identified a total of 192 patients; 137 underwent LLIF with PEEK (212 levels) and 55 had LLIF with pTi (97 levels). After propensity score matching, a total of 97 lumbar levels remained in each treatment group. After matching, there were no statistically significant differences between groups in baseline characteristics. Levels treated with pTi were significantly less likely to exhibit subsidence (any grade) compared to those treated with PEEK (8% vs 27%, p = 0.001). Five (5.2%) levels treated with PEEK required reoperation for subsidence, but only 1 (1.0%) level treated with pTi required reoperation for subsidence (p = 0.12). Given subsidence and revision rates experienced in the cohorts in this study, the pTi interbody device is economically superior to PEEK in a single-level LLIF as long as its cost is at least $1185.94 lower than that of PEEK. CONCLUSIONS: The pTi interbody device was associated with less subsidence, but statistically similar revision rates after LLIF. pTi is potentially a superior economic choice at this study's reported revision rate.

Utility of serum ketone levels for assessment of myocardial glucose suppression for 18F-fluorodeoxyglucose PET in patients referred for evaluation of endocarditis.

BACKGROUND: 18F-FDG PET/CT is used to diagnose cardiac sarcoidosis and endocarditis. It requires myocardial glucose utilization (MGU) suppression to avoid false positives, which occur in up to 20% of patients. Serum beta-hydroxybutyrate (BHB) levels may help identify incomplete suppression of MGU. We determined the optimal timing and diagnostic thresholds to identify incomplete suppression of MGU. METHODS AND RESULTS: We retrospectively identified 114 patients referred for 18F-FDG PET/CT for endocarditis, wherein myocardial uptake outside of paravalvular regions is not related to pathology and can be confidently ascribed as being due to inadequate suppression of MGU. Patients followed a high-fat, low-carbohydrate diet and received heparin. Serum BHB, insulin, glucose and hemoglobin A1c were measured. Maximum standardized uptake value (SUVmax) of left ventricle (LV) and mean SUV (SUVmean) in LV blood pool (LVBP) was measured. Logistic regression and area under the receiver-operating characteristic analyses were used to quantify the relationship between biomarkers and MGU suppression. A threshold of BHB ≥ 0.35 mmol·L-1 to detect suppression resulted in sensitivity of 88% and specificity of 61%. A threshold of BHB ≥ 0.95 mmol·L-1 resulted in sensitivity of 45% and specificity of 100%. AUC was 0.87. BHB measured ~ 4 hours prior to 18F-FDG injection performed similarly to or better than later timepoints. CONCLUSIONS: Serum BHB levels are useful for assessing suppression of MGU and could simplify interpretation of 18F-FDG PET/CT inflammation studies.

Impacts of risk assessment data, assumptions, and methods: Considering the evidence for diacetyl and 2,3-pentanedione.

The articles published as part of the Frontiers in Public Health research topic, "Investigating exposures and respiratory health in coffee workers" present research findings that better characterize exposures to diacetyl and 2,3-pentanedione and inform our understanding of the health risks posed by these exposures. Although various research groups and organizations have conducted risk assessments to derive occupational exposure limits (OELs) for diacetyl, differences in the data used and assumptions made in these efforts have resulted in a wide range of recommended OELs designed to protect human health. The primary drivers of these differences include the decision to use data from human or animal studies in conducting a quantitative risk assessment, and the application of uncertainty factors (UF) to derive an OEL. This Perspectives paper will discuss the practical implications of these decisions, and present additional commentary on the potential role that the recent investigation of human exposures to relatively low concentrations of α-diketones, specifically diacetyl and 2,3-pentanedione, may play in supporting qualitative or quantitative human health risk assessments.

In vitro and in silico assessment of new beta amino ketones with antiplasmodial activity.

BACKGROUND: Based on the current need for new drugs against malaria, our study evaluated eight beta amino ketones in silico and in vitro for potential antimalarial activity. METHODS: Using the Brazilian Malaria Molecular Targets (BraMMT) and OCTOPUS® software programs, the pattern of interactions of beta-amino ketones was described against different proteins of P. falciparum and screened to evaluate their physicochemical properties. The in vitro antiplasmodial activities of the compounds were evaluated using a SYBR Green-based assay. In parallel, in vitro cytotoxic data were obtained using the MTT assay. RESULTS: Among the eight compounds, compound 1 was the most active and selective against P. falciparum (IC50 = 0.98 µM; SI > 60). Six targets were identified in BraMMT that interact with compounds exhibiting a stronger binding energy than the crystallographic ligand: P. falciparum triophosphate phosphoglycolate complex (1LYX), P. falciparum reductase (2OK8), PfPK7 (2PML), P. falciparum glutaredoxin (4N0Z), PfATP6, and PfHT. CONCLUSIONS: The physicochemical properties of compound 1 were compatible with the set of criteria established by the Lipinski rule and demonstrated its potential as a drug prototype for antiplasmodial activity.

Antifungal compounds, GC-MS analysis and toxicity assessment of methanolic extracts of Trichoderma species in an animal model.

Fungi of the genus Trichoderma have been marketed for the management of diseases of crops. However, some Trichoderma species may produce toxic secondary metabolites and it should receive due attention to ensure human safety. In this study, we investigated the in vitro antagonistic potential of T. asperellum AU131 and T. longibrachiatum AU158 as microbial biocontrol agents (MBCAs) against Fusarium xylarioides and the associated antagonistic mechanism with bioactive substances. Swiss albino mice were used to evaluate the in vivo toxicity and pathogenicity of T. asperellum AU131 and T. longibrachiatum AU158 methanolic extracts and spore suspensions, respectively, in a preliminary safety assessment for use as biofungicides. Gas Chromatography-Mass Spectrometry (GC-MS) was used to profile volatile organic metabolites (VOCs) present in the methanolic extracts. The agar diffusion assay of the methanolic extracts from both T. asperellum AU131 and T. longibrachiatum AU158 were effective at a concentration of 200 µg/mL (1×107 spores/mL), causing 62.5%, and 74.3% inhibition, respectively. A GC-MS analysis of methanolic extracts from both bioagents identified 23 VOCs which classified as alcohols, acids, sesquiterpenes, ketones and aromatic compounds. The oral administration of methanolic extracts and spore suspensions of each Trichoderma species to female Swiss albino mice over 14 days did not show any significant signs of toxicity, mortality or changes to body weight. It can be concluded that the tested spore suspensions and methanolic extracts were not pathogenic or toxic, respectively, when administered to Swiss albino mice at various doses.

Molecular insights on ar-turmerone as a structural, functional and pharmacophoric analogue of synthetic mosquito repellent DEET by comprehensive computational assessment.

Mosquitoes are vectors for a variety of infectious illnesses, and chemical synthetic insecticides have made it possible to control them effectively. Mosquito repellents are a typical means of keeping mosquitos at bay. Because of its main effectiveness of skin permeability, N,N-Diethyl-meta-toluamide (DEET) is one of the most extensively used mosquito repellents but a dangerous synthetic chemical. DEET was identified about a decade ago to inhibit mosquito's Odorant Binding Protein 1 (OBP1), impairing the mosquito's ability to recognise the host body odour. OBP1 has been identified as a possible target for the development of new mosquito repellents since its discovery. Essential oils from different plants, on the other hand, have been used to repel mosquitos since antiquity. One essential oil from the Curcuma longa (Zingiberales: Zingiberaceae) rhizome display mosquito repellent properties, according to the literature. Furthermore, one of the phytochemicals found in abundance in C. longa essential oil, ar-turmerone, exhibits mosquito repellency as comparable to synthetic DEET. Till date studies on in-silico interaction of natural ar-turmerone with OBP1, which we depict in our current work are scarce. Further, there exist no published reports demonstrating the literary evidence on detailed insights of interaction of DEET with OBP1 along with Molecular Dynamics (MD) simulation studies. We further performed detailed molecular investigations using pharmacophore analysis of ar-turmerone and compared it with DEET, where our findings in the current manuscript unveils for the first time that ar-turmerone is a functional, structural and pharmacophoric analogue of DEET.

Qualitative Assessment of Titanium versus Carbon Fiber/Polyetheretherketone Pedicle Screw-Related Artifacts: A Cadaveric Study.

BACKGROUND: Dorsal instrumentation and decompression are the mainstays of spinal tumor treatment. Replacing titanium screws with carbon fiber-reinforced polyetheretherketone (CFRP) screws can reduce imaging artifacts on neural structures and perturbations of radiation dose. Further reduction of metal content in such screws might enhance the benefit. The aim of this study was to assess the artifacts produced by all-titanium screws (Ti-Ti), CFRP thread-titanium screw heads (C-Ti), and all-CFRP screws (C-C). METHODS: A cadaveric spine was used to place Ti-Ti, C-Ti, and C-C consecutively from T2 to S1. Computed tomography and 1.5T and 3T magnetic resonance imaging were performed for each screw system. Axial T1- and T2-weighted sequences of representative thoracic and lumbar regions were assessed for artifacts. The artifacts were classified as not relevant, considerable, or severe. RESULTS: We evaluated 92 screws and made 178 artifact assessments. The artifacts were clearly visible in computed tomography scans but did not influence the visualization of intraspinal structures. Severe magnetic resonance imaging artifacts were found in 28% (17/60, mostly in the thoracic spine) of Ti-Ti, 2% (1/60, all T1 sequences) of C-Ti, and 0% of C-C, and considerable artifacts were found in 47% (28/60) of Ti-Ti, 10% (6/60, only 1 T2 sequence) of C-Ti, and 0% of C-C screws (P < 0.001). CONCLUSIONS: CFRP pedicle screws reduced the artifact intensity in spinal structures compared with titanium screws, and may be beneficial for planning radiotherapy and for follow-up imaging. C-C demonstrated an enhanced effect on dorsal structures.

Assessment of Customized Alveolar Bone Augmentation Using Titanium Scaffolds vs Polyetheretherketone (PEEK) Scaffolds: A Comparative Study Based on 3D Printing Technology.

Customized alveolar bone augmentation provides sufficient and precisely regenerated bone tissue for subsequent dental implant placement. Although some clinical cases have confirmed the successful use of the patient-specific polyetheretherketone (PEEK) scaffolds, the biomechanical property and osteogenic performance of the patient-specific PEEK scaffolds remain unclear. The objectives of this study were (1) to evaluate the space maintenance capacity and osteogenic performance of the patient-specific PEEK scaffolds for customized alveolar bone augmentation and (2) to compare the biomechanical properties of three-dimensionally printed titanium scaffolds and PEEK scaffolds. Both titanium scaffolds and PEEK scaffolds were designed and manufactured via additive manufacturing technology combined with computer-aided design (CAD). In three-point bending tests, the bending strength of the PEEK scaffold was about 1/3 that of the titanium scaffold. Accordingly, the equivalent strain value of the internal bone graft beneath the PEEK scaffold was about 3 times that beneath the titanium scaffold in finite element analysis, but the maximum deformations of both scaffolds were less than 0.05 mm. Meanwhile, in in vivo experiments, it is demonstrated that both scaffolds have similar space maintenance capacity and bone ingrowth efficiency. In conclusion, patient-specific PEEK scaffolds showed significantly lower biomechanical strength but comparable space maintenance and osteogenic properties to the titanium counterpart. Compared with traditional guided bone regeneration (GBR) surgery, both patient-specific PEEK and titanium scaffolds can achieve excellent osteogenic space maintenance ability. This study provides a preliminary basis for the clinical translation of the nonmetallic barrier membrane in customized alveolar bone augmentation.

Water-Mediated ortho-Carboxymethylation of Aryl Ketones under Ir(III)-Catalytic Conditions: Step Economy Total Synthesis of Cytosporones A-C.

An expeditious Ir(III)-catalyzed carboxymethylation of aryl ketone with diazotized Meldrum's acid has been developed in aqueous medium. Flavanone and chromanone were also found to be facile substrates with the developed catalytic system. Mechanistic studies revealed the active catalytic species and the role of water in the reaction process as hydroxy and proton sources. Employing the developed method, total synthesis of cytosporone A was achieved in two steps and that of cytosporones B-C was achieved in three steps starting from resorcinol.