OBJECTIVE: This study investigates the interaction of zirconia and polyetheretherketone (PEEK) with indirect composite in fixed dental prostheses. This investigation aimed to assess the shear bond strength (SBS) and color stability of zirconia and PEEK before and after aging, addressing critical concerns in dental restorative applications.
METHODS: The current in vitro study used 96 samples, 48 of which were divided into two groups, zirconia and PEEK, before and after thermocycling. A dual-axis chewing simulator was used for thermocycling. SBS was measured using a universal testing machine, and color stability was checked using a reflective spectrophotometer.
METHODS: Ninety-six samples were categorized into zirconia and PEEK groups, each with subgroups undergoing thermocycling. Samples were prepared using computer-aided design/computer-aided manufacturing milling and veneered with composite resin. Thermocycling involved 10,000 cycles, simulating stress levels equivalent to approximately 1 year of clinical use. SBS was assessed using standardized tests. Stereomicroscopic analysis was performed to evaluate the type of failure. Color stability of the core materials with indirect composite was done using a spectrophotometer before and after aging.
METHODS: Statistical analysis included paired t-tests and independent t-tests in SPSS software.
RESULTS: The results revealed that SBS values for composite on PEEK decreased from 13.86 ± 0.164 MPa before thermocycling to 13.46 ± 0.185 MPa after thermocycling, with a significant difference (P < 0.005). However, both pre- and postthermocycling values for PEEK were higher than zirconia. The t-test confirmed the lower bond strength of composite to zirconia, with a noteworthy improvement after aging. Stereomicroscopic images revealed adhesive failure for the zirconia group and mixed (adhesive and cohesive) failure for the PEEK group. ΔE values were 3.21 ± 0.127 and 2.93 ± 0.142 for zirconia and PEEK groups, respectively (P < 0.005).
CONCLUSIONS: Within the limitations of this study, it can be deduced that PEEK is a feasible substitute for zirconia when used in conjunction with indirect composite for the fabrication of dental prostheses.

OBJECTIVE: Synthetic inorganic materials are commonly used as reinforcing agents in polyetheretherketone (PEEK) composite, whereas natural organic plant-based reinforcing agents are negligible. Surface hardness, roughness, and wettability are indicative factors of osseointegration behavior to be used as an implant material. This study evaluated micro surface hardness (MSH), nano surface hardness (NSH), surface roughness (SR), and contact angle (CA) of PEEK-Azadirachta indica reinforced at 10 wt%, 20 wt%, and 30 wt%.
METHODS: This was an in vitro study.
METHODS: Neem (A. indica) leaf nanoparticles were prepared and reinforced with PEEK powder at 10%, 20%, and 30% weight ratios by injection molding. Sixty specimens underwent the microhardness and CA testing using a digital microhardness tester, and CA goniometer, respectively, and later nanoindentation test to analyze the nanohardness and SR.
METHODS: A one-way ANOVA test with a 95% confidence interval for MSH and NSH, SR, and CA was performed on the samples. A post hoc Bonferroni test was conducted (α = 0.05) to compare the groups.
RESULTS: There was a significant increase in nanohardness (P = 0.000) with zero difference in microhardness (P = 0.514). The addition of 10 wt%, 20 wt%, and 30 wt% nanoparticles increased the SR value of the pure PEEK from 273.19 nm to 284.10 (3.99%), 296.91 (8.68%), and 287.54 (5.24%), respectively. In the analysis of the CA, CA 20% shows the lowest angle (63.69) with the highest for control specimens (82.39). There is an increase in the PEEK composite SR with a decrease in CA.
CONCLUSIONS: The addition of plant-derived nanoparticles into the PEEK matrix has a significant impact on the hardness and hydrophobicity enhancing cell growth and osteoblastic differentiation during osseointegration of dental implants.

BACKGROUND: The research focused on the postoperative effect of using interbody fusion cage in lumbar posterior lamina decompression and interbody fusion with pedicle screw by comparing the postoperative effect of using 3D printing (Ti6Al4V) and PEEK material interbody fusion cage.
METHODS: Ninety-one patients with lumbar degenerative diseases from the Department of Spine Surgery of Tianjin Hospital were included in the study cohort. They were divided into 3D group (n = 39) and PEEK group (n = 52) according to the use of interbody fusion cage. The imaging data of the patients were collected and the postoperative data of the 2 groups were compared to evaluate patients\' health status and the recovery of lumbar structure and function after operation.
RESULTS: Combined with the degree of fusion, the clinical effect of 3D printing titanium alloy interbody fusion cage was comprehensively judged. At the last follow-up, the JOA score, ODI index, VAS, prolo function score, and SF-36 scale of the 2 groups showed that the clinical symptoms were better than those before operation (P < .05). The height of intervertebral disc, the area of intervertebral foramen and the physiological curvature of lumbar vertebrae increased in varying degrees after operation (P < .05). At the last follow-up, the vertebral cage fusion rates were as high as 89.13% and 90.91% in the 3D and PEEK groups, with collapse rates of 6.5% and 4.5%, respectively. There were 10 cases of cage displacement in 3D group and 7 cases of cage displacement in PEEK group. There was no significant difference between the 2 groups (P > .05).
CONCLUSIONS: In conclusion, 3D printed (Ti6Al4V) interbody fusion cage can obtain good clinical effect in the surgical treatment of lumbar degenerative diseases. Posterior lumbar lamina decompression, bilateral pedicle screw fixation combined with 3D printed cage interbody fusion is excellent in rebuilding the stability of lumbar vertebrae. 3D printed interbody fusion cage can be an ideal substitute material for intervertebral bone grafting. The stable fusion time of interbody fusion cage after lumbar fusion is mostly from 3 months to half a year after operation.

OBJECTIVE: To determine whether it was feasible, safe and acceptable for ambulance clinicians to use capillary blood ketone meters for \'high-risk\' diabetic ketoacidosis (DKA) recognition and fluid initiation, to inform the need for a full-powered, multi-centre trial.
METHODS: Adopting a stepped-wedge controlled design, participants with hyperglycaemia (capillary blood glucose >11.0 mmol/L) or diabetes and unwell were recruited. \'High-risk\' DKA intervention participants (capillary blood ketones ≥3.0 mmol/L) received paramedic-led fluid therapy. Participant demographic and clinical data were collated from ambulance and hospital care records. Twenty ambulance and Emergency Department clinicians were interviewed to understand their hyperglycaemia and DKA care experiences.
RESULTS: In this study, 388 participants were recruited (Control: n = 203; Intervention: n = 185). Most presented with hyperglycaemia, and incidence of type 1 and type 2 diabetes was 18.5% and 74.3%, respectively. Ketone meter use facilitated \'high-risk\' DKA identification (control: 2.5%, n = 5; intervention: 6.5%, n = 12) and was associated with improved hospital pre-alerting. Ambulance clinicians appeared to have a high index of suspicion for hospital-diagnosed DKA participants. One third (33.3%; n = 3) of Control and almost half (45.5%; n = 5) of Intervention DKA participants received pre-hospital fluid therapy. Key interview themes included clinical assessment, ambulance DKA fluid therapy, clinical handovers; decision support tool; hospital DKA management; barriers to hospital DKA care.
CONCLUSIONS: Ambulance capillary blood ketone meter use was deemed feasible, safe and acceptable. Opportunities for improved clinical decision making, support and safety-netting, as well as in-hospital DKA care, were recognised. As participant recruitment was below progression threshold, it is recommended that future-related research considers alternative trial designs.
RESULTS: gov: NCT04940897.

OBJECTIVE: To evaluate the safety and performance of an implantable near-infrared (NIR) spectroscopy sensor for multi-metabolite monitoring of glucose, ketones, lactate, and ethanol.
METHODS: This is an early feasibility study (GLOW, NCT04782934) including 7 participants (4 with type 1 diabetes (T1D), 3 healthy volunteers) in whom the YANG NIR spectroscopy sensor (Indigo) was implanted for 28 days. Metabolic challenges were used to vary glucose levels (40-400 mg/dL, 2.2-22.2 mmol/L) and/or induce increases in ketones (ketone drink, up to 3.5 mM), lactate (exercise bike, up to 13 mM) and ethanol (4-8 alcoholic beverages, 40-80g). NIR spectra for glucose, ketones, lactate, and ethanol levels analyzed with partial least squares regression were compared with blood values for glucose (Biosen EKF), ketones and lactate (GlucoMen LX Plus), and breath ethanol levels (ACE II Breathalyzer). The effect of potential confounders on glucose measurements (paracetamol, aspartame, acetylsalicylic acid, ibuprofen, sorbitol, caffeine, fructose, vitamin C) was investigated in T1D participants.
RESULTS: The implanted YANG sensor was safe and well tolerated and did not cause any infectious or wound healing complications. Six out 7 sensors remained fully operational over the entire study period. Glucose measurements were sufficiently accurate (overall mean absolute (relative) difference MARD of 7.4%, MAD 8.8 mg/dl) without significant impact of confounders. MAD values were 0.12 mM for ketones, 0.16 mM for lactate, and 0.18 mM for ethanol.
CONCLUSIONS: The first implantable multi-biomarker sensor was shown to be well tolerated and produce accurate measurements of glucose, ketones, lactate, and ethanol.
BACKGROUND: Clinical trial identifier: NCT04782934.

Bis-octanoyl (R)-1,3-butanediol (BO-BD) is a novel ketone ester (KE) ingredient which increases blood beta-hydroxybutyrate (BHB) concentrations rapidly after ingestion. KE is hypothesized to have beneficial metabolic effects on health and performance, especially in older adults. Whilst many studies have investigated the ketogenic effect of KE in young adults, they have not been studied in an exclusively older adult population, for whom age-related differences in body composition and metabolism may alter the effects. This randomized, observational, open-label study in healthy older adults (n = 30, 50% male, age = 76.5 years, BMI = 25.2 kg/m2) aimed to elucidate acute tolerance, blood BHB and blood glucose concentrations for 4 hours following consumption of either 12.5 or 25 g of BO-BD formulated firstly as a ready-to-drink beverage (n = 30), then as a re-constituted powder (n = 21), taken with a standard meal. Both serving sizes and formulations of BO-BD were well tolerated, and increased blood BHB, inducing nutritional ketosis (≥ 0.5mM) that lasted until the end of the study. Ketosis was dose responsive; peak BHB concentration (Cmax) and incremental area under the curve (iAUC) were significantly greater with 25 g compared to 12.5 g of BO-BD in both formulations. There were no significant differences in Cmax or iAUC between formulations. Blood glucose increased in all conditions following the meal; there were no consistent significant differences in glucose response between conditions. These results demonstrate that both powder and beverage formulations of the novel KE, BO-BD, induce ketosis in healthy older adults, facilitating future research on functional effects of this ingredient in aging.

The use of polyetheretherketone (PEEK) for cementless femoral total knee arthroplasty (TKA) components is of interest due to several potential advantages, e.g. the use in patients with metal hypersensitivity. Additionally, the stiffness of PEEK closer resembles the stiffness of bone, and therefore, peri-prosthetic stress-shielding may be avoided. When introducing a new implant material for cementless TKA designs, it is important to study its effect on the primary fixation, which is required for the long-term fixation. Finite element (FE) studies can be used to study the effect of PEEK as implant material on the primary fixation, which may be dependent on patient factors such as age, gender and body weight index (BMI). Therefore, the research objectives of this study were to investigate the effect of PEEK vs cobalt-chrome (CoCr) and patient characteristics on the primary fixation of a cementless femoral component. 280 FE models of 70 femora were created with varying implant material and gait and squat activity. Overall, the PEEK models generated larger peak micromotions than the CoCr models. Distinct differences were seen in the micromotion distributions between the PEEK and CoCr models for both the gait and squat models. The micromotions of all femoral models significantly increased with BMI. Neither gender nor age of the patients had a significant effect on the micromotions. This population study gives insights into the primary fixation of a cementless femoral component in a cohort of FE models with varying implant material and patient characteristics.

BACKGROUND: As polyether ether ketone (PEEK) is a relatively new material in dentistry, its bonding properties with regard to dental acrylic base materials are not fully known. To ensure the long-term success of removable dentures with a PEEK framework, the base materials must be well bonded to each other.
OBJECTIVE: The study aimed to investigate the effects of different kinds of surface roughening treatment on PEEK and acrylic resin bonding.
METHODS: Eighty PEEK specimens (N = 80) were randomly divided into 5 groups (n = 16 per group) and subjected to various surface roughening treatment (control, grinding, sandblasting, tribochemical silica coating (CoJet), and sulfuric acid etching). Heat-polymerized acrylic resin was applied to the treated surfaces of the PEEK specimens. The shear bond strength (SBS) test, environmental scanning electron microscopy (ESEM) analysis and three-dimensional (3D) surface topography analysis were performed. The statistical analysis of the data was conducted using the analysis of variance (ANOVA) and Tukey\'s multiple comparison test.
RESULTS: The one-way ANOVA showed significant differences in the SBS values between the groups (p = 0.001). Sandblasting, tribochemical silica coating and sulfuric acid etching resulted in high SBS values (p = 0.001). The highest SBS values were observed in the sulfuric acid etching group (8.83 ±3.63 MPa), while the lowest SBS values were observed in the control group (3.33 ±2.50 MPa).
CONCLUSIONS: The additional roughening treatment applied to the PEEK surface increases the bond strength with heat-polymerized acrylic resin.

Relative to carbohydrate (CHO) alone, exogenous ketones followed by CHO supplementation during recovery from glycogen-lowering exercise have been shown to increase muscle glycogen resynthesis. However, whether this strategy improves subsequent exercise performance is unknown. The objective of this study was to assess the efficacy of ketone monoester (KME) followed by CHO ingestion after glycogen-lowering exercise on subsequent 20 km (TT20km) and 5 km (TT5km) best-effort time trials. Nine recreationally active men (175.6 ± 5.3 cm, 72.9 ± 7.7 kg, 28 ± 5 y, 12.2 ± 3.2% body fat, VO2max = 56.2 ± 5.8 mL· kg BM-1·min-1; mean ± SD) completed a glycogen-lowering exercise session, followed by 4 h of recovery and subsequent TT20km and TT5km. During the first 2 h of recovery, participants ingested either KME (25 g) followed by CHO at a rate of 1.2 g·kg-1·h-1 (KME + CHO) or an iso-energetic placebo (dextrose) followed by CHO (PLAC + CHO). Blood metabolites during recovery and performance during the subsequent two-time trials were measured. In comparison to PLAC + CHO, KME + CHO displayed greater (p < 0.05) blood beta-hydroxybutyrate concentration during the first 2 h, lower (p < 0.05) blood glucose concentrations at 30 and 60 min, as well as greater (p < 0.05) blood insulin concentration 2 h following ingestion. However, no treatment differences (p > 0.05) in power output nor time to complete either time trial were observed vs. PLAC + CHO. These data indicate that the metabolic changes induced by KME + CHO ingestion following glycogen-lowering exercise are insufficient to enhance subsequent endurance time trial performance.

OBJECTIVE: Although changes in circulating tumour DNA (ctDNA) in breast cancer are well described, the kinetics of their fluctuations has not been described over short timescales. We investigated ctDNA dynamics during alternating cycles of chemotherapy and hormonal treatment in pre-treated patients with oestrogen receptor-positive metastatic breast cancer.
METHODS: Patients received alternating, 9-week cycles of eribulin and aromatase inhibitors (AIs). The clinical primary endpoint, progression-free survival (PFS), was monitored at 3, 6 and 9 months; secondary endpoints, clinical benefit rate (CBR), safety and tolerability profiles, were also assessed. Importantly, ctDNA fluctuations were monitored using the Oncomine™ Breast cfDNA assay to test whether biomarkers may change rapidly between chemotherapy and aromatase inhibitor (AI) treatment in the setting of advanced breast cancer, potentially reflecting disease dynamics.
RESULTS: The median PFS was 202 days (95% CI: 135-undefined) and 235 days (95% CI: 235-undefined) at 6 and 9 months, respectively, with a 50% CBR at both 6 and 9 months. Dynamic changes in ctDNA were observed in short timescales between chemotherapy and AI treatment and support the clinical benefit (CB) seen in individual patients and, critically, appear informative of acquired resistance in real time.
CONCLUSIONS: Changes in ctDNA can occur rapidly and reflect changes in patients\' clinical tumour responses (NCT02681523).