True Failure Research Articles

Determining the Failure Rate of Direct Restorations-Chart Review versus Electronic Health Record Reports.

Amalgam and composite restorations are used to treat minor dental issues. University of Michigan, School of Dentistry Electronic Health Record (EHR) reports show a 2.31% failure rate for amalgam and 1.14% for composite. Our study aims to determine the true failure rates through manual EHR chart reviews. Patient data from the University of Michigan School of Dentistry were utilized-216 amalgam restorations from 2020 to 2022 and 350 composite restorations in 2021 were searched. We defined failure and retreatment as replacing a restoration with the same material and failure and alternate treatment as replacing restoration with an alternative treatment within one year. The failure rate refers to a combination of replacement with the same and alternative treatment material within one year. For Amalgam: 1.85% failed and were retreated; 7.87% failed and were received an alternate treatment. Composite: 9.71% failed and retreated; 2.86% failed and received alternate treatment. In total anterior composite: 10.5% retreated, 2.6% failed; posterior composite: 9.1% retreated, 3.0% failed. Our study revealed higher restoration failure rates than the reports extracted in the EHR. This highlights the need to foster a culture of precise documentation to align EHR reports with hand-search findings.

THE SURVIVAL OF TOTAL ANKLE ARTHROPLASTIES: A DATA LINKAGE STUDY FROM THE NATIONAL JOINT REGISTRY

IntroductionDespite the increasing numbers of ankle replacements that are being performed there are still limited studies on the survival of ankle replacements and comparisons between different implants. The primary aim of this study is to link NJR data with NHS digital data to determine the true failure rates of ankle replacements. Secondary outcomes include analysis risk factors for failure, patient demographics and outcomes of individual prosthesis.MethodsA data linkage study combined National Joint Registry Data and NHS Digital data. The primary outcome of failure is defined as the removal or exchange of any components of the implanted device inserted during ankle replacement surgery. Life tables and Kaplan Meier survival charts demonstrated survivorship. Cox proportional hazards regression models with the Breslow method used for ties were fitted to compare failure rates.Results5,562 primary ankle replacement were recorded on the NJR. The 1-year survivorship was 98.8% (95% CI 98.4%–99.0%), 5-year survival in 2725 patients was 90.2% (95% CI 89.2%–91.1%), and 10-year survival in 199 patients was 86.2% (95% CI 84.6%–87.6%).When using a Cox regression model for all implants with over 100 implantations using the Infinity as the reference, only the Star (Hazard ratio 1.60 95% CI 0.87–2.96) and Inbone (HR 0.38 95% CI 0.05–2.84) did not produce significantly worse survivorship.ConclusionAnkle replacements have increased in numbers over the past decade, and the currently used implants have lower failure rates than older prosthesis. It is expected that in the future the outcomes of ankle replacements will continue to improve.

DIASTOLIC DYSFUNCTION EVALUATION IN CARDIAC AMYLOIDOSIS: BEYOND TRADITIONAL PARAMETERS TO DISCRIMINATE BETWEEN TRUE HEART FAILURE WITH PRESERVED EJECTION FRACTION AND MIMICS

Abstract Background Diastolic dysfunction in cardiac amyloidosis (CA), according to current guidelines, can be classified using mitral flow velocities, mitral annular e’ velocity, E/e’ ratio, tricuspid regurgitation jet and left atrial (LA) maximal volume. However, LA minimal volume and the ratio between LA and left ventricular (LV) volumes at end–diastole, known as left atrio–ventricular coupling index (LACI), have recently been proposed to refine prognosis and peak atrial longitudinal strain (PALS) has been demonstrated to better stratify diastolic dysfunction. Aim of the Study To evaluate, in patients with CA: 1) the role of LACI as marker of LV diastolic dysfunction; 2) whether LACI could discriminate cardiomyopathy from normal cardiac function; 3) whether LACI and/or PALS could help discriminate between true heart failure with preserved ejection fraction (HFpEF) and amyloidotic cardiomyopathy (HFpEF–mimic). Methods We retrospectively analyzed 63 patients with CA and compared them with 80 true HFpEF patients and 70 healthy people; echocardiography was performed at the time of the diagnosis and diastolic function was characterized according to current guidelines. Results In patients with CA, LACI significantly increased as diastolic dysfunction worsened (P for trend < 0.0001) and significantly correlated with LV filling pressures estimated by E/e’ ratio (beta = 0.65, P < 0.0001) and pulmonary artery systolic pressure (beta = 0.63, P < 0.0001). LACI, after adjustment for age, gender and body mass index (BMI), was significantly higher in CA [0.62 (95%CI 0.52–0.70)] and in HFpEF [0.61 (95%CI 0.55–0.68)] than in controls [0.29 (95%CI 0.19–0.39)], while the difference between the two diseased populations was not statistically significant; a cut–off value of 0.45 was able to discriminate between controls and diseased patients (sensitivity = 95%, specificity = 94%, area under ROC curve = 0.98). PALS, after adjustment for age, gender and BMI, was significantly lower in CA [11.1 (95%CI 8.4–13.8%) and 8.4 (95%CI 3.5–13.3%) respectively in ATTR and AL] than in HFpEF [17.4 (95%CI 15.6–19.3%)], and a cut–off value of 9.9% was able to discriminate between them (sensitivity = 89%, specificity = 73%, area under ROC curve = 0.86). Conclusions LACI is a novel index able to discriminate between normal and diseased patients. In CA, it shows good correlation with diastolic dysfunction and LV filling pressures. PALS can be used to discriminate between true HFpEF and CA.

Rabies postexposure prophylaxis protocol option for unvaccinated domestic animals, Texas: 2010-2019.

To assess data on rabies postexposure prophylaxis (PEP) in domestic animals following Texas' protocol and to describe preexposure and postexposure vaccination failures from 2010 through 2019. 1,218 unvaccinated animals that received PEP, 925 unvaccinated animals that were euthanatized instead of receiving PEP, and 3 preexposure vaccinated dogs that developed rabies. Zoonotic incident reports from 2010 through 2019 were reviewed for information regarding animals with no known rabies vaccination that received PEP or were euthanatized in accordance with state protocol after exposure to a laboratory-confirmed rabid animal; reports were also reviewed for any preexposure and postexposure vaccination failures. The state-required PEP protocol was to immediately vaccinate the animal against rabies, confine the animal for 90 days, and administer booster vaccines during the third and eighth weeks of the confinement period. From 2010 through 2019, 1,218 exposed animals received PEP; 99.8% did not develop rabies. Three failures were recorded, all in animals < 12 weeks of age when PEP was initiated. Additionally, 925 exposed animals were euthanatized instead of receiving PEP. One true preexposure vaccination failure was recorded. The Texas PEP protocol was used during the 10-year period. Results indicated that this protocol is a viable option for unvaccinated domestic animals exposed to rabies. Alternative protocols warrant additional consideration.

True triaxial energy evolution characteristics and failure mechanism of deep rock subjected to mining-induced stress

In deep rock engineering, complex stress conditions are encountered, which leads to difficulties in engineering disaster prevention and control. To investigate the failure behaviors and mechanisms of deep rock mining, a series of tests was designed for mining-induced failure at different simulated depths using a multifunctional true triaxial geophysical (TTG) apparatus. The results showed that both the simulated depth and mining disturbance affected the deformation characteristics of the sandstone specimens. With increasing depth, the strength gradually increased. The peak strength increased fastest in the single-sided unloading failure test (SUFT) and slowest in the stress loading and unloading failure test (SLUFT). The failure mode also changed significantly. In the displacement loading failure test (DLFT), the failure mode gradually changed from tensile failure to shear failure. In the SLUFTs, the failure mode of the specimens changed from layer cracking to shear failure. In the SUFTs, the failure mode of the specimen transitioned from layer cracking to tensile shear failure and then to shear failure. Scholars have previously proposed an elastic strain energy calculation method for true triaxial stress conditions. An elastic strain energy calculation method applicable to different mining disturbance was proposed under true triaxial stress conditions, and the evolution characteristics of the work done, elastic strain energy, and dissipated energy were analyzed. Additionally, a method to quantitatively characterize the relationship between macroscopic cracks and dissipated energy was proposed, and microscopic fracture analysis was performed using scanning electron microscopy (SEM). Different depths and various types of mining-induced failure were fully considered, and the specimen deformation, failure type, energy evolution (including dissipation), and failure mechanisms were analyzed. The results can provide guidance for deep underground engineering projects.

Reevaluate low-concentration ether-based electrolytes for lithium metal batteries

Ether is regarded as an exceptional solvent in liquid electrolytes for lithium (Li) metal batteries due to its outstanding compatibility with Li metal anode. Low salt concentration in ether-based electrolytes (LCEEs) is highly favorable to reducing the cost of future Li metal batteries. Nevertheless, LCEEs have been reported to exhibit poor anodic stability (as low as 4.0 V vs. Li/Li+), therefore considered unsuitable for practical batteries using LiNixMnyCozO2 as cathodes and charge up to 4.4 V. Here, using 1.0 M lithium bis(fluorosulfonyl)imide (LiFSI) in 1,2-dimethoxyethane (DME) as the baseline, we demonstrate the intrinsic anodic stability window of LCEE to be above 4.5 V. We revealed the true failure mechanism of LCEE to be various electrochemical reactions with different working electrodes (WEs). We further provide electrolyte and electrode design rules to prevent LCEE decomposition, as well as electrode and packaging materials corrosion at high voltage. This study highlights the importance of previously overlooked battery component compatibility in electrolyte development and offers valuable insights into battery engineering considerations toward high-energy and cost-effective Li metal batteries.

Experimental Study of the Role of Gap Size on Bolt Failure in Clevis and Lug Joints

Abstract A common standard for conservatively evaluating the required bolt strength in a clevis–lug joint is to assume that the bolt must survive under an interaction equation that combines loading caused by bending, shear, and axial preload–induced stresses. In practice, this leads to unnecessarily large bolts because the true failure mode is typically closer to simple shear with some bending stresses. In this experimental study, a clevis and lug joint with a variable gap between the clevis arms was used to determine the force necessary to break high strength bolts with various gaps between the clevis and the lug, ranging from pure shear (no gap) to a gap 2.8 times the diameter of the bolt. The testing results clearly show that failure occurs at forces that are often significantly higher than would be predicted by classic, closed-form analysis of the combined loading. In particular, the bolt failed at the force predicted by simple double shear failure theory for gap sizes up to half of the bolt diameter, and for larger gaps, the failure force was consistently higher than would be predicted by classic interaction equations. Thus, although assuming failure that is due to combined bending, shear, and axial stresses is safely conservative, the necessary bolt size is actually significantly smaller than this method predicts.

Gross failure rates and failure modes for a commercial AI-based auto-segmentation algorithm in head and neck cancer patients.

Artificial intelligence (AI) based commercial software can be used to automatically delineate organs at risk (OAR), with potential for efficiency savings in the radiotherapy treatment planning pathway, and reduction of inter- and intra-observer variability. There has been little research investigating gross failure rates and failure modes of such systems. 50 head and neck (H&N) patient data sets with "gold standard" contours were compared to AI-generated contours to produce expected mean and standard deviation values for the Dice Similarity Coefficient (DSC), for four common H&N OARs (brainstem, mandible, left and right parotid). An AI-based commercial system was applied to 500 H&N patients. AI-generated contours were compared to manual contours, outlined by an expert human, and a gross failure was set at three standard deviations below the expected mean DSC. Failures were inspected to assess reason for failure of the AI-based system with failures relating to suboptimal manual contouring censored. True failures were classified into 4 sub-types (setup position, anatomy, image artefacts and unknown). There were 24 true failures of the AI-based commercial software, a gross failure rate of 1.2%. Fifteen failures were due to patient anatomy, four were due to dental image artefacts, three were due to patient position and two were unknown. True failure rates by OAR were 0.4% (brainstem), 2.2% (mandible), 1.4% (left parotid) and 0.8% (right parotid). True failures of the AI-based system were predominantly associated with a non-standard element within the CT scan. It is likely that these non-standard elements were the reason for the gross failure, and suggests that patient datasets used to train the AI model did not contain sufficient heterogeneity of data. Regardless of the reasons for failure, the true failure rate for the AI-based system in the H&N region for the OARs investigated was low (∼1%).

Attrition after Referral for Chimeric Antigen Receptor T-Cell (CAR-T) Products in Multiple Myeloma (MM)

Introduction: Chimeric antigen receptor T-cell (CAR-T) products have shown an impressive response in relapsed/refractory MM patients (pts). The pivotal KarMMa-3 (Otero-Rodriguez P et al, NEJM, 2023) and CARTITUDE-4 (San Miguel J, et al, NEJM, 2023) studies showed that infusion of idecabtagene vicleucel (ide-cel) and ciltacabtagene autoleucel (cilta-cel) was superior to other standard of care therapies. However, some pts in these studies were unable to receive CAR-T even after being deemed eligible for apheresis. In KarMMa-3, 12/140 pts who completed apheresis did not receive their cells, 3 due to disease progression/death and 1 due to a true manufacturing failure. In CARTITUDE-4, 16/113 pts who completed apheresis did not receive their cells, with 9 dying prior to infusion and 0 having true manufacturing failures. Other studies have shown that factors like peripheral CD3 count (PCD3) affected the probability of a successful apheresis (Rytlewski et al, ASCO 2022). Known reasons for CAR-T attrition include lack of available spots, true manufacturing failures, death post-apheresis but prior to infusion (PAD; due to infection and/or disease progression), and cell product issues necessitating an expanded access program (EAP). This study aimed to find patient- and disease-specific variables associated with increased rates of CAR-T attrition. Methods: We retrospectively reviewed the medical records of all pts who were approved for either ide-cel or cilta-cel as standard of care (SOC) treatment for MM at MD Anderson between August 2021 and June 2023. The study was approved by the Institutional Review Board at MD Anderson. Pts were classified by CAR-T product received, and the number of apheresis procedures required to produce viable product. They were then classified based on need for EAP. Descriptive statistics including mean, standard deviation, median, and range for continuous variables such as age and lab measurements, and frequency counts and percentages for categorical variables such as stage, gender, comorbidity, treatment, and response were obtained. Fisher's exact test or Chi-square test was used to evaluate the association between two categorical variables. Wilcoxon rank sum test or Kruskal-Wallis test was used to evaluate the difference in a continuous variable between or among patient groups. Kaplan-Meier method was used to estimate overall survival and progression free survival for the pts who received CAR-T infusion. Statistical software SAS 9.4 (SAS, Cary, NC) and S-Plus 8.2 (TIBCO Software Inc., Palo Alto, CA) were used for all the analyses. Results: Data from 153 pts were included. High-risk features, defined as the presence of high-risk cytogenetics, extramedullary disease, or R-ISS stage III, were present in 125 (81.7%), and 84 (54.9%) were penta-refractory. CAR-T cells were infused successfully in 86 (56.2%) pts, including 5 who were infused via EAP. Of the 67 pts who did not get infused, 26 (38.2%) died prior to apheresis, 8 (11.9%) were PAD, 10 (14.9%) were treated with a bispecific agent due to lack of available manufacturing slots, and 3 (4.5%) had true manufacturing failures. Of the 8 patients that were PAD, 2 died due to progression of disease, 4 died from complications of inpatient bridging chemo, and 2 died from complications from lymphodepleting chemo. For all pts with manufacturing failures, their apheresis had a low dose, with 2 out of 3 having PCD3 &amp;lt; 5%. The mean absolute lymphocyte count (ALC) at apheresis was significantly higher in the EAP group (n=5) compared with the non-EAP group, but significantly lower in the manufacturing failures group (n=3) compared with the successful CAR-T manufacturing (n=86) group (Table 1). For the overall cohort of pts receiving CAR-T (n=86), the median progression-free (PFS) and overall survival (OS) rates were 11.7 and 18.8 months, respectively (Figure 1). Conclusion: The PFS and OS for all pts, including those who received their CAR-T through EAP, were excellent. ALC at the time of apheresis was a predictor of true manufacturing failure. Surprisingly, pts successfully treated on EAP had an increased ALC compared with those receiving SOC. Further comparative studies of pts with barriers to CAR-T are needed to identify other variables that increase adverse outcomes so that these can be addressed. Hopefully, with a better understanding of the barriers patients have, we can ensure that more pts get access to this efficacious treatment.

Current status data with two competing risks and time-dependent missing failure types

In competing risks data, in practice, there may be lack of information or uncertainty about the true failure type, termed as ‘missing failure type’, for some subjects. We consider a general pattern of missing failure type in which we observe, if not the true failure type, a set of possible failure types containing the true one. In this work, we focus on both parametric and non-parametric estimation based on current status data with two competing risks and the above-mentioned missing failure type. Here, the missing probabilities are assumed to be time-dependent, that is, dependent on both failure and monitoring time points, in addition to being dependent on the true failure type. This makes the missing mechanism non-ignorable. We carry out maximum likelihood estimation and obtain the asymptotic properties of the estimators. Simulation studies are conducted to investigate the finite sample properties of the estimators. Finally, the methods are illustrated through a data set on hearing loss.

P‐175: AI‐based Multimodal Architecture for Video Anomaly Detection in Large OLED Panel Manufacturing

This paper proposes an AI‐based multimodal architecture for anomaly detection in a video footage of a smart carrier which is used for monitoring alignment status, grinding of rollers and vibration of a carrier for manufacturing line of OLED (Organic Light Emitting Diodes) panels. The proposed multimodal architecture has a two‐stream structure. The first stream extracts a candidate anomaly region in image frames sampled from the video by DL‐based segmentation. Thereafter, the candidate region is determined whether it is a true failure or not by comparing the region with a reference image which was previously obtained in a normal setup status. The second stream calculates a dense optical flow with sparse areas using consecutive video frames. By observing change between (n)th, reference, (n‐3)th and (n‐7)th images, it is determined with sound analysis whether the smart carrier experiences vibration during movement. The overall detection rate of three anomalies is 97%, and processing takes only 40% of total video time.

Ti/RuO2-IrO2 anodic electrochemical oxidation composting leachate biochemical effluent: Response surface optimization and failure mechanism

In this work, the electrolytic process conditions for the electrochemical oxidation (EO) of composting leachate biochemical effluent (CLBE) were optimized via the response surface methodology (RSM). Meanwhile, a comparative study had been done on the failure characteristics of Ti/RuO2–IrO2 anodes in a single electrolyte solution system (H2SO4 and NaCl) and real wastewater (CLBE) by accelerated life tests, respectively. The RSM optimization results showed that the COD, NH3–N and TN removal rates were 50.53%, 100% and 95.61% at 30 min, respectively, with a desirability value of 0.993. In parallel, the electrochemical and material characterizations were carried out on the electrodes before and after failure, by which the failure mechanism of Ti/RuO2–IrO2 anodes was clarified. On the whole, the true failure in the H2SO4 solution was attributed to coating dissolution and Ti substrate oxidation. In contrast, the electrode exhibited “apparent failure” due to the “bubble effect” in both NaCl and CLBE solutions, and the “effective roughness” formed compensated for the loss of activity caused by the absence of the coating. Besides, additional dissolution of the Ti substrate occurred in the CLBE solution due to the current edge effect and the presence of organic matter. This paper takes the actual wastewater as the research object and reveals its electrode failure mechanism, which provides a theoretical basis and reference for the subsequent optimization of the actual electrode service life.

The Generalized Mohr-Coulomb Failure Criterion

With the construction of supertall buildings such as high earth dams, the linear envelope of the Mohr-Coulomb (M-C) failure criterion fitted to lower confined pressure would significantly underestimate the loading capacity of foundations, causing a huge increase in the amount of earthwork. Given that the M-C criterion has dominated in the stability analysis of geotechnical structures, it is proposed in this study that the M-C criterion remain invariant in form but the cohesion c and the frictional factor f be related to the coefficient of intermediate principal stress b, called the Generalized Mohr-Coulomb (GMC) criterion. In other words, c and f are both functions of b, written as c(b) and f(b). In the simplest way, the GMC criterion for soils, a true three-dimensional failure criterion, can be established by using a piece of conventional triaxial apparatus. The GMC has a non-smooth strength surface like its conventional version. However, we prove from true triaxial tests and the characteristic theory of stress tensors that the failure surfaces in the stress space should be non-smooth per se for b = 0 or 1. Comparisons with other prominent failure criteria indicate that the GMC fits the test data best.

Image-aided physical and compression characterisation of expanded polystyrene geofoam

The present study focuses on an advanced and accurate characterisation of the compressive behaviour of expanded polystyrene (EPS) geofoam with the aid of imaging techniques. To this end, four types of EPS geofoam with nominal densities varying from 15 kg/m3 to 30 kg/m3 are used. Initially, a detailed physical characterisation is carried out including image-based microstructural quantification (cell size, void fraction, population density), homogeneity using ultrasonic pulse velocity and apparent density. Insights into the compression behaviour of the geofoams, including true strains and failure patterns, are further gathered through full-field strain behaviour in the block using two-dimensional image correlation analysis. For the first time, the effect of nominal densities on the Poisson's ratio of geofoam is also studied through image analysis. The study reveals that compressive response is significantly influenced by homogeneity, which is manifested by the changes in microstructure and apparent density of the geofoam. Furthermore, the image analysis provides insights into the development of failure patterns and strain localisation and their dependency on density, comprehending the geofoam's complex behaviour. Predictions of compressive response based on apparent density and non-destructive tests are developed. The study further recommends safety factors for determining permissible and yield stresses based on statistical analysis.

Fatigue testing on bitumen binder using different column specimen shapes

The use of cylindrical column specimens to characterise the fatigue degradation of bituminous materials is useful to unify existing fatigue testing methods at different length scales (i.e., asphalt binder, mastic and mortar). However, these specimens commonly fail at the interface between the test material and the steel holders. To overcome this difficulty, this study investigates the fatigue characterisation of four binders using four different notched column geometries. The benefit of these geometries is that they induce failure at the center of the specimen. Finite element simulations were used to determine correction factors to account for the influence of the specimens' shape. Curves of the fatigue life as a function of the applied effective strain were successfully obtained for the different binders. The results show that the use of these notched geometries ensures true cohesive failure within the specimen and is an effective method to characterise fatigue damage in asphalt binders.

Impact of G29179T mutation on two commercial PCR assays for SARS-CoV-2 detection

Nucleic acid amplification test (NAAT) is the gold standard for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) detection. However, genetic mutations in the virus can affect the result. Cycle threshold (Ct) values of N genes and their association with mutations using SARS-CoV-2 positive specimens diagnosed by the Xpert Xpress SARS-CoV-2 were examined in this study. In total, 196 nasopharyngeal swab specimens were tested for SARS-CoV-2 infection using the Xpert Xpress SARS-CoV-2, and 34 were positive. WGS was performed for four outlier samples with increased ΔCt identified by Scatterplot analysis as well as seven control samples without increased ΔCt in the Xpert Xpress SARS-CoV-2. The presence of the G29179T mutation was identified as a cause of increased ΔCt. PCR using the Allplex™ SARS-CoV-2 Assay did not show a similar increase in ΔCt. Previous reports focusing on N-gene mutations and their effects on SARS-CoV-2 testing including the Xpert Xpress SARS-CoV-2 were also summarized. While a single mutation that impacts one target of a multiplex NAAT is not a true detection failure, mutation compromising NAAT target region can cause confusion of the results and render the assay susceptible to diagnostic failure.

Proof testing to improve the reliability and lifetime of ceramic dental prostheses.

Ceramic dental prostheses exhibit increasing failure rates with service time. In particular, veneered crowns and bridges are susceptible to chipping and other fracture modes of failure. The purpose of this manuscript is to introduce a computational methodology and associated software that can predict the time-dependent probability of failure for ceramic prostheses and subsequently design proof test protocols to significantly enhance their reliabilities and lifetimes. Transient reliability and corresponding proof testing theories are introduced. These theories are coded in the Ceramic Analysis and Reliability Evaluation of Structures (CARES/Life) code. This software will be used to demonstrate the predictive capability of the theory as well as its use in designing proof test protocols to significantly improve the reliability (survival probability) and lifetime for dental prostheses. A three-unit fixed dental prosthesis (FDP) with zirconia core (ZirCAD) and veneering ceramic (ZirPress) are used to compare the predicted probabilities of failure to general clinical results. In addition, the capability to use proof testing to significantly improve the performance (reliability and lifetime) for this restoration is demonstrated. The probability of failure, Pf, after five years without proof testing is predicted to be 0.337. This compares to clinical studies showing the failure rate to be between 0.2 and 0.23 after 5 years. After 10 years, reference 18 found the clinical failure rate for similar bridges (but not the same) to be up to 0.28 compared to the predicted Pf of 0.38. The difference may be due to the analysis applying the load at an inclination of 75° which is more critical than vertical loading. In addition, clinical studies often report a simple survival rate instead of using Kaplan-Meier analysis to properly account for late enrollees. Therefore, true clinical failure rates may be higher than reported and may more closely match the predictions of this manuscript. The effectiveness of proof testing increases with selecting materials less susceptible to slow crack growth (higher SCG exponent, N). For example, proof testing the ZirPress glass-veneered bridges with N=43.4 analyzed in this manuscript at 400N bite force for 1s which induces a failure rate during proof testing of 0.31, reduces the Pf of bridges not proof tested from 0.45 to an attenuated-proof-tested probability of failure Pfa of 0.21 after 20 years of usage. If another material is selected with improved resistance to SCG of N=60 and the same loading conditions, the failure rate for the proof tested bridges after 20 years of service drops to 2 in 10,000 from 2.4 in 100 had they been not proof tested. The failure rate during proof testing for this material would be 5.1 in 100. Proof testing a material with absolutely no susceptibility to SCG at the same service load (in this case 285N, not even the 400N load used above) results in 0 % failure rate and is of course independent of time. The transient reliability and proof test theory presented in this paper and associated computational software CARES/Life were successful in predicting the performance of ceramic dental restorations when compared to clinical data. Well-designed proof test protocols combined with proper material selection can significantly enhance the reliabilities and lifetimes of ceramic prostheses. This proof test capability can be a translational technology if properly applied to dental restorations.

On the seismic stability of soil slopes containing dual weak layers: true failure load assessment by finite-element limit-analysis

On the seismic stability of soil slopes containing dual weak layers: true failure load assessment by finite-element limit-analysis

Birth anthropometry among three Asian racial groups in Singapore: proposed new growth charts

ObjectiveWe analysed birth anthropometry of babies of Chinese, Malay and Indian ancestry living in Singapore with an aim to develop gestational age (GA) and gender-specific birth anthropometry charts and compare...

P056Oral contraceptive adherence and pregnancy rates in estetrol/drospirenone pooled phase 3 trials

<h3>Objectives</h3> To assess the relationship of adherence and pregnancy in participants using an estetrol and drospirenone combined oral contraceptive. <h3>Methods</h3> We pooled data from two parallel, multicenter, open-label, phase 3 trials (US/Canada and Europe/Russia) that enrolled healthy participants aged 16–50 to receive estetrol 15 mg/drospirenone 3 mg in a 24/4 regimen for up to 13 cycles. We limited this efficacy analysis to participants aged 16–35 at screening. Participants reported adherence using paper diaries. We assessed the relationship between number of missed pills and pregnancies in at-risk cycles (≥1 confirmed intercourse and no other contraceptive use) and when pregnancies occurred during product use with test for trend and chi-square analyses as appropriate. <h3>Results</h3> Among 3,027 participants in this analysis, 31 on-treatment pregnancies occurred during 26,455 at-risk cycles of use for an overall Pearl Index of 1.52 (95% CI, 1.04–2.16). Pregnancies occurred in 0.09%, 0.25%, 0.83%, and 1.6% of cycles in which participants reported missing 0 (n=25,613 cycles), 1 (n=405 cycles), 2 (n=121 cycles) and >2 (n=314 cycles) active pills, respectively (p<0.0001). Pregnancy rates ranged from 0-0.21% per cycle with no significant trend by cycle (p=0.45). About half (48.4%) of all pregnancies occurred in the first four cycles, with pregnancies occurring in 0.17% of cycles vs. 0.08% during cycles 5–8 and 0.10% in cycles 9–13 (p=0.07). <h3>Conclusions</h3> Pregnancy occurs more frequently when combined oral contraceptive users report missing pills and exceeds 1% only when >2 pills are missed. A 0.09% pregnancy risk among users reporting no missed pills likely approximates a true method failure rate.