3D printing of ultra-thin veneers made of lithium disilicate using the LCM method in a digital workflow: A feasibility study.

OBJECTIVE: This article highlights the feasibility of the additive fabrication of ultra-thin veneers made of lithium disilicate using the lithography-based ceramic manufacturing (LCM) method. CLINICAL CONSIDERATIONS: An esthetical appealing restoration of anterior teeth with thin ceramic veneers is considered one of the ultimate challenges in restorative dental prosthetics. These sophisticated restorations can be fabricated in different ways. Both analog and digital subtractive manufacturing processes have been used to date. Either of the methods is highly demanding for the dental technician and dental engineering due to the required low ceramic layer thickness. CONCLUSION: Modern additive manufacturing methods, for example LCM technology, enable the production of ultra-thin lithium disilicate veneers with layer thicknesses of down to 0.2 mm and could therefore represent a viable alternative for this indication in the future. CLINICAL SIGNIFICANCE: Digital technologies can help streamline workflows, make the outcome more predictable and reproducible, and even further optimize therapeutic restorative options such as highly esthetic veneers for anterior teeth. The reduced material thickness allows for a true non-prep solution or minimally invasive preparation.

Digital implant planning and guided implant surgery - workflow and reliability.

Modern oral implantology and implant prosthetics depend on comprehensive diagnostics and precise planning to ensure the desired outcome and meet the patient's and the dentist's expectations. In this context, digital implant planning and guided implant surgery based on three-dimensional radiographic data and the digitised intraoral surfaces can be of excellent service. They provide valuable information and permit stringent backward planning to optimise the implantological and prosthetic result, improving the safety and efficiency of the surgical procedure and rendering the restorative outcome more predictable in terms of function, biology and aesthetics. However, template-guided implant surgery carries its own specific risks in terms of manufacturing inaccuracies and application errors. These possible sources of error must be recognised and carefully considered in order to avoid adverse consequences.

Comparison of adjustable male slings and artificial urinary sphincter in the treatment of male urinary incontinence: a retrospective analysis of patient selection and postoperative continence status.

PURPOSE: To analyze and compare preoperative patient characteristics and postoperative results in men with stress urinary incontinence (SUI) selected for an adjustable male sling system or an artificial urinary sphincter (AUS) in a large, contemporary, multi-institutional patient cohort. METHODS: 658 male patients who underwent implantation between 2010 and 2012 in 13 participating institutions were included in this study (n = 176 adjustable male sling; n = 482 AUS). Preoperative patient characteristics and postoperative outcomes were analyzed. For statistical analysis, the independent T test and Mann-Whitney U test were used. RESULTS: Patients undergoing adjustable male sling implantation were less likely to have a neurological disease (4.5% vs. 8.9%, p = 0.021), a history of urethral stricture (21.6% vs. 33.8%, p = 0.024) or a radiation therapy (22.7% vs. 29.9%, p = 0.020) compared to patients that underwent AUS implantation. Mean pad usage per day (6.87 vs. 5.82; p < 0.00) and the ratio of patients with a prior incontinence surgery were higher in patients selected for an AUS implantation (36.7% vs. 22.7%; p < 0.001). At maximum follow-up, patients that underwent an AUS implantation had a significantly lower mean pad usage during daytime (p < 0.001) and nighttime (p = 0.018). Furthermore, the patients' perception of their continence status was better with a subjective complete dry rate of 57.3% vs. 22.0% (p < 0.001). CONCLUSIONS: Patients selected for an AUS implantation showed a more complex prior history and pathogenesis of urinary incontinence as well as a more severe grade of SUI. Postoperative results reflect a better continence status after AUS implantation, favoring the AUS despite the more complicated patient cohort.

Effects of BDNF Val66Met genotype and schizophrenia familial risk on a neural functional network for cognitive control in humans.

Cognitive control represents an essential neuropsychological characteristic that allows for the rapid adaption of a changing environment by constant re-allocation of cognitive resources. This finely tuned mechanism is impaired in psychiatric disorders such as schizophrenia and contributes to cognitive deficits. Neuroimaging has highlighted the contribution of the anterior cingulate cortex (ACC) and prefrontal regions (PFC) on cognitive control and demonstrated the impact of genetic variation, as well as genetic liability for schizophrenia. In this study, we aimed to examine the influence of the functional single-nucleotide polymorphism (SNP) rs6265 of a plasticity-related neurotrophic factor gene, BDNF (Val66Met), on cognitive control. Strong evidence implicates BDNF Val66Met in neural plasticity in humans. Furthermore, several studies suggest that although the variant is not convincingly associated with schizophrenia risk, it seems to be a modifier of the clinical presentation and course of the disease. In order to clarify the underlying mechanisms using functional magnetic resonance imaging (fMRI), we studied the effects of this SNP on ACC and PFC activation, and the connectivity between these regions in a discovery sample of 85 healthy individuals and sought to replicate this effect in an independent sample of 253 individuals. Additionally, we tested the identified imaging phenotype in relation to schizophrenia familial risk in a sample of 58 unaffected first-degree relatives of schizophrenia patients. We found a significant increase in interregional connectivity between ACC and PFC in the risk-associated BDNF 66Met allele carriers. Furthermore, we replicated this effect in an independent sample and demonstrated its independence of structural confounds, as well as task specificity. A similar coupling increase was detectable in individuals with increased familial risk for schizophrenia. Our results show that a key neural circuit for cognitive control is influenced by a plasticity-related genetic variant, which may render this circuit particular susceptible to genetic and environmental risk factors for schizophrenia.

Histo-anatomic 3D printing of dental structures.

The creation of dental restorations with natural appearance and biomechanics represents a major challenge for the restorative team. The manufacturing-process of high-aesthetic restorations from tooth-coloured restorative materials is currently dominated by manual manufacturing procedures and the outcome is highly dependent on the knowledge and skills of the performing dental technician. On the other hand, due to the simplicity of the manufacturing process, CAD/CAM restorations from different material classes gain more and more acceptance in the daily routine. Multi-layered restorations show significant aesthetic advantages versus monolithic ones, but are difficult to fabricate using digital technologies. The key element for the successful automated digital fabrication of aesthetic anterior restorations seems to be the form of the individual dentine core as defined by dentine enamel junction (DEJ) covered by a more transparent layer of material imitating the enamel layer to create the outer enamel surface (OES). This article describes the possibilities and technologies available for so-called '4D-printing'. It introduces the digital manufacturing process of multilayered anterior teeth using 3D multipart printing, taking the example of manufacturing replicas of extracted intact natural teeth.

Species-conserved reconfigurations of brain network topology induced by ketamine.

Species-conserved (intermediate) phenotypes that can be quantified and compared across species offer important advantages for translational research and drug discovery. Here, we investigate the utility of network science methods to assess the pharmacological alterations of the large-scale architecture of brain networks in rats and humans. In a double-blind, placebo-controlled, cross-over study in humans and a placebo-controlled two-group study in rats, we demonstrate that the application of ketamine leads to a topological reconfiguration of large-scale brain networks towards less-integrated and more-segregated information processing in both the species. As these alterations are opposed to those commonly observed in patients suffering from depression, they might indicate systems-level correlates of the antidepressant effect of ketamine.

Reconstruction of the vertical jaw relation using CAD/CAM.

There can be severe loss of the vertical dimension of occlusion due to chemical, mechanical and traumatic causes. This can give rise to both esthetic and functional problems for the patient. Restoration is possible usually only by redesigning the occlusal surfaces. The prosthetic readjustment of the vertical jaw relation represents a considerable intervention in the stomatognathic system, requiring predictable, minimally invasive methods. Long-term provisional solutions clearly superior to pure splint therapy can be produced by means of new CAD/CAM techniques. They are inserted permanently and only in this way can the patient test the new occlusal situation and the success of treating functional disorders be verified. A further major advantage then becomes apparent when the final restoration is produced. The previously adjusted and tested occlusion is retained and every tooth can be treated and restored individually. Long treatment sessions are thus a thing of the past.

Digital dentistry: an overview of recent developments for CAD/CAM generated restorations.

As in many other industries, production stages are increasingly becoming automated in dental technology. As the price of dental laboratory work has become a major factor in treatment planning and therapy, automation could enable more competitive production in high-wage areas like Western Europe and the USA. Advances in computer technology now enable cost-effective production of individual pieces. Dental restorations produced with computer assistance have become more common in recent years. Most dental companies have access to CAD/CAM procedures, either in the dental practice, the dental laboratory or in the form of production centres. The many benefits associated with CAD/CAM generated dental restorations include: the access to new, almost defect-free, industrially prefabricated and controlled materials; an increase in quality and reproducibility and also data storage commensurate with a standardised chain of production; an improvement in precision and planning, as well as an increase in efficiency. As a result of continual developments in computer hardware and software, new methods of production and new treatment concepts are to be expected, which will enable an additional reduction in costs. Dentists, who will be confronted with these techniques in the future, require certain basic knowledge if they are to benefit from these new procedures. This article gives an overview of CAD/CAM-technologies and systems available for dentistry today.

Role transition from graduate to staff nurse: a qualitative analysis.

The purpose of this study was to describe the initial steps in the role transition of graduate to staff nurse. During the first 3 weeks of an orientation to a clinical unit in an acute care hospital, graduate nurses and their preceptors used feedback sheets to document the learning activities of the graduate nurse, communicate the need for and evaluation of learning experiences, and plan activities to meet the continued needs of graduate nurses. Daily feedback sheets from 27 orientees and preceptors were analyzed using content analysis. A model representing the process and components of role transition was developed. The model was based on five themes which emerged from the data: Real Nurse Work, Guidance, Transitional Processes, Institutional Context, and Interpersonal Dynamics. Analysis of results revealed that the initial transition of a graduate nurse to the role of a staff nurse was a dynamic and interactive process occurring between the graduate nurse and the preceptor. Guided learning led to progress in balancing increasingly complex care within a specific institution. Interpersonal dynamics among staff, preceptors, and graduate nurses affected the process of role transition.

Intravenous vitamin K1 prior to orthotopic heart transplantation: effects in vivo and in vitro.

BACKGROUND: Vitamin K1 is used to reverse warfarin's anticoagulant action. It is unclear whether intravenous vitamin K1 is safe or efficacious prior to urgent cardiac surgery. METHODS: We retrospectively and prospectively examined the effects of preoperative intravenous vitamin K1 in vivo (administered for warfarin reversal immediately before heart transplantation) on intraoperative blood product utilization, hemodynamics and coagulation parameters. We also determined the direct effects of vitamin K1 in vitro on rings of human saphenous vein and internal mammary artery. RESULTS: In the retrospective limb, 29 of 67 patients were administered vitamin K1 preoperatively via slow intravenous infusion. Vitamin K1 administration produced no adverse outcome but did not affect subsequent perioperative use of blood products. In the prospective limb (n = 10), vitamin K1 significantly (P < or = 0.01, Student t-test) altered mean arterial pressure (from 85 +/- 15 to 76 +/- 16 mmHg), systemic vascular resistance (from 1364 +/- 308 to 1078 +/- 252 dyn.s.cm-5), and cardiac index (from 2.3 +/- 0.3 to 2.7 +/- 0.3 L/min/m2) (mean +/- SD). Significant decreases in prothrombin time (19.8 +/- 2.7 to 17.7 +/- 1.8 s) and activated clotting time (164 +/- 26 to 137 +/- 24 s) were observed at 60 min. In vitro vitamin K1 (10(-7) to 10(-4) M) had no effect on the tone of noradrenaline-constricted rings. CONCLUSIONS: Vitamin K1, administered by intravenous infusion prior to heart transplantation, did not alter subsequent perioperative blood product administration. Vitamin K1 rapidly reversed the anticoagulant effect of warfarin and produced modest hemodynamic changes. The decrease in systemic vascular resistance is probably not due to a direct effect of vitamin K1 on vascular smooth muscle.

Immediate postural responses to total nasal obstruction.

Twenty-five nasal breathing adults were radiographically examined before and after their nasal respiratory pattern had been artificially eliminated for a period of 1 hour. Six angular and six linear variables were measured to determine the extent of the postural reflexive behavior of the cranium, mandible, hyoid bone, tongue, and lips. All subjects coped in their own individual way with the environmental impact. The most generalized findings were parting of the lips (p < 0.05), a drop in mandibular position (p < 0.001), and a downward movement of the hyoid bone (p < 0.05). Cranial extension did not reach statistical significance (p = 0.06). The relevance of these findings relative to primate experiments and human clinical research is discussed. If the same postural reactions are maintained over a long-term period, they may be instrumental in influencing the vertical craniofacial growth pattern.

Craniofacial osseointegration of a large midfacial bone-anchored combination maxillofacial prosthesis: a clinical report.

The combination of retentive clips and magnets has been used with favorable results for smaller facial prostheses. This patient's large midfacial defect created the need for an attachment design that would retain an intraoral obturator prosthesis and a large silicone facial prosthesis. The advantages of this design include having an obturator that is separately attached by clips to the framework. This allows the patient more ease in insertion and removal of the prosthesis. It also allows for better oral hygiene. The magnets aid the patient in the proper alignment of the facial prosthesis. The O-ring attachment was not a complicated technique in this patient's treatment. The patient can, without the use of a mirror, snap the rubber matrix O-ring attachment over the patrix attachment on the framework. This resulted in a retentive facial prosthesis, which helped the patient feel more secure. The silicone margins were well adapted to the patient's skin, which allows the use of thin translucent margins and the elimination of the inherent problems associated with the use of adhesives.

A conservative fixed partial denture: a clinical report.

The restoration of a patient's edentulous area with a three-unit fixed partial denture is described. The denture consisted of an etched-metal bonded retainer and metal ceramic pontic with a nonrigid connector in combination with a conventional inlay retainer. The incorporation of a nonrigid connector permitted the use of dissimilar metals and cements with retainers of different retention potentials. This technique provides minimal reduction of tooth structure with supragingival margins for improved periodontal health.

Regioisomeric 5(3)-aminomethyl-3(5)-phenylisoxazoles: synthesis, spectroscopic discrimination, and muscarinic activity.

The regioselective synthesis of isomeric 5(3)-aminomethyl-3(5)-phenyl isoxazoles using different methods is described. Spectroscopic data, especially mass spectrometric fragmentation, were used to identify and characterize the regioisomers. The muscarinic activity of these isoxazoles was assayed on isolated guinea-pig ileum and atria as well as on isolated rabbit vas deferens.

A two-stage impression technique for custom facial prostheses.

A two-stage impression technique that uses polyvinyl siloxane and irreversible hydrocolloid in a custom impression tray is described. The technique records the tissues to be contacted by the facial prosthesis with minimal distortion with the patient in an upright position and facial musculature at rest. The procedure is simple, accurate, and it eliminates some of the shortcomings of other techniques.

Patients who die awaiting heart transplantation.

In the United States, heart donor availability has increasingly failed to keep pace with rising demand. Transplant data were obtained from the United Network for Organ Sharing for 1988, 1989, and 1990 and by survey of 50 heart transplantation centers, which performed 1932 transplantations between 1983 and 1989. According to the United Network for Organ Sharing, 512 patients on the waiting list died in 1988; 527, in 1989; 650, in 1990, and if present trends continue more than 800 will have died in 1991. Similar numbers of patients were inactivated or removed from the list each year. Only 49% of patients (1647 of 3390) on the heart transplant waiting list at some time in 1988 underwent the procedure in that year. For 1989 the figure fell to 42% (1630 of 3915 patients). Survey data revealed a threefold increase in the ratio of the number of patients who died/number of patients who underwent transplantation from 0.07 in 1983 to 0.21 in 1989 and in the ratio (number of patients who died+number of patients who were removed from the list)/number of patients who underwent transplantation from 0.12 in 1983 to 0.38 in 1989. The major causes of death among waiting patients were congestive heart failure (46%) and arrhythmia (29%). From 1983 to 1989, 55% (134 of 243) of those patients with documented urgency status died in the intensive care unit; 45% (109 of 243) died elsewhere. Waiting time for patients dying in the intensive care unit rose from 10.7 days in 1985 to 50.3 days in 1989; patients dying out of the intensive care unit waited 103.7 days in 1985 and 85.6 days in 1989. In conclusion, the number and proportion of potential recipients who die awaiting heart transplantation is increasing every year. Congestive heart failure and arrhythmia are the major causes of death, and similar numbers of patients die in and out of the intensive care unit.

Cyclosporine-associated central neurotoxicity after heart transplantation.

Cyclosporine central neurotoxicity has been described after bone marrow, kidney, and liver transplantation but has not been well documented after heart transplantation. This case illustrates severe reversible neurotoxicity after heart transplantation with characteristic radiographic changes in magnetic resonance imaging.