Dynamic and static moduli of elasticity of resin-based materials.

OBJECTIVES: The purpose of this study was to assess and compare the elastic moduli of 34 resin-based materials using a dynamic and a static method. The effect of water storage was also studied up to 6 months. METHODS: Five samples of each material were prepared according to ISO-4049. The dynamic moduli were first determined non-destructively from the fundamental period of the vibrating specimen, then the static moduli were determined by a three-point bending test. The percentages of fillers by weight were determined by ashing in air at 900 degrees C. RESULTS: Low values were obtained with flowable composites as well as with two packable resin composites. Correlations were found between the static and the dynamic modulus of elasticity (r = 0.94; p = 0.0001) as well as between the weight percentage of fillers and the moduli of elasticity (r = 0.82; p < 0.05 for static modulus and r = 0.90; p < 0.05 for the dynamic modulus) both at 24h. Water storage significantly affected both static and dynamic moduli of elasticity (ANOVA two factors; p < 0.05). SIGNIFICANCE: The low moduli of the flowable composites do not allow their use in posterior cavities under high stress. However, this does not exclude their use for minimally-invasive Class I cavities when the opposing tooth is stabilized to a large amount on the natural enamel.The Grindosonic method is very useful and simple for determining the dynamic moduli although it gives higher values than the static one. The elastic modulus evolution of resin-based materials after water storage is unpredictable since different patterns were observed as a function of time.     

Incidence of coronary artery by-pass graft following percutaneous transluminal coronary angioplasty

Two hundred fifty eight patients had percutaneous transluminal coronary angioplasty. Of those, 48 cases underwent surgical revascularization for unsuccessful angioplasty. Sex was not a risk factor. Timely surgical revascularization reversed acute ischemia and/or myocardial infarction or limited the size of the infarction in 32 of the 48 patients or 67%. Revascularization procedures were performed in six out of forty-eight patients who had previous aortocoronary by-pass surgery and attempted PTCA, none had any complications. Death occurred in one out of forty-eight patients, or 2%. Femoral-femoral by-pass devices, in addition to intra-aortic balloon devices, should be available in the cardiac catheterization laboratory. Patients with multi-vessel disease are at greater risk of angioplasty and surgery. Sixteen out of 23 patients (70%) who had emergency revascularization procedures had multi-vessel disease. In one patient with borderline renal function, emergency surgery after PTCA with a large amount of renograffin dye injected caused renal failure and led to permanent dialysis.     

Results of flexor-to-extensor and extensor brevis tendon transfer for correction of the crossover second toe deformity

Between 1990 and 1995, 38 patients (42 feet) underwent repair for crossover toe deformity, 31 (35 feet) of whom returned for final examination at an average of 51.6 months (range, 24-81 months). Causes included trauma, iatrogenic, and unknown. Presenting complaints included dorsal pain with either metatarsalgia or joint pain, isolated metatarsophalangeal (MP) joint pain, metatarsalgia, painful plantar callus, metatarsalgia and joint pain, and painful dorsal callus. All patients were treated with one of two operative techniques, either the flexor-to-extensor tendon transfer or the extensor brevis tendon transfer. Choice of procedure depended on the stage of preoperative deformity. Twenty-four patients were completely satisfied with the surgical correction, 6 were satisfied with reservations, and 1 was dissatisfied. The average postoperative AOFAS score for all patients was 85 points (range, 54-100 points), which correlated strongly with patient satisfaction. Twenty-two patients stated that they had no postoperative pain, 8 reported some pain, and 1 had frequent pain at the corrected toe. In 30 feet, there was no recurrence; three patients had mild residual crossover toe deformity, and two patients had recurrent deformity, although all MP joints were stable. Follow-up radiographs demonstrated substantial reduction in MP joint angles in both the AP (from 7 degrees to -1 degree) and lateral (from 45 degrees to 25 degrees) projections. This article reviews the surgical technique of both procedures, proposes specific indications for each, and presents outcomes. Based on our findings, the extensor brevis tendon transfer is appropriate for stage 1, stage 2, and flexible stage 3 deformities. Flexor-to-extensor tendon transfer is appropriate for rigid stage 3 and stage 4 deformities and for all patients with a symptomatic neuroma of the second web space (where the extensor brevis transfer is not possible). Stiffness of the MP joint is a potential problem with the flexor-to-extensor tendon transfer.     

Chlorhexidine spray as an adjunct in the control of dental biofilm in children with special needs

The aim of this study was to evaluate the clinical effectiveness of .12% chlorhexidine applied via spray and the acceptance. A total of 26 individuals with mental health issues, aged 7–14, were included into two groups: placebo (control, n = 13) and chlorhexidine (experimental, n = 13). Both groups received two daily applications of spray during 2 months. The periodontal conditions were evaluated by the simplified oral hygiene index (OHI‐S) and gingival index (GI). The evaluation of acceptance of the application method (spray) was assessed by questionnaire. Data were analyzed with nonparametric tests, with a significance level of 5%. Regarding the OHI‐S index, only the experimental group showed significant change during the evaluations (p < 0.001). Regarding the GI, both groups showed significant changes during the evaluations. The method of application was well accepted by patients and caregivers, and .12% chlorhexidine solution applied via spray significantly reduced the rates of dental and gingival biofilm.     

The Various Applications of 3D Printing in Cardiovascular Diseases

Purpose of Review

To highlight the various applications of 3D printing in cardiovascular disease and discuss its limitations and future direction.

Recent Findings

Use of handheld 3D printed models of cardiovascular structures has emerged as a facile modality in procedural and surgical planning as well as education and communication.

Summary

Three-dimensional (3D) printing is a novel imaging modality which involves creating patient-specific models of cardiovascular structures. As percutaneous and surgical therapies evolve, spatial recognition of complex cardiovascular anatomic relationships by cardiologists and cardiovascular surgeons is imperative. Handheld 3D printed models of cardiovascular structures provide a facile and intuitive road map for procedural and surgical planning, complementing conventional imaging modalities. Moreover, 3D printed models are efficacious educational and communication tools. This review highlights the various applications of 3D printing in cardiovascular diseases and discusses its limitations and future directions.

     

Receptor for advanced glycation endproduct modulators: a new therapeutic target in Alzheimer’s disease

Introduction: Reduction in the deposition of amyloid β (Aβ) has been the primary target for Alzheimer’s disease (AD) therapeutics recently, but in clinical trials this approach has generally been unsuccessful. A common feature of AD pathology is a complex inflammatory component that could be a target for treatment. One feature of this inflammation has been the involvement of the receptor for advanced glycation endproducts (RAGE), whose ligands include advanced glycation-endproduct-modified proteins as well as lipids and Aβ, which are found at elevated levels in AD brains.

Areas covered: In this article, the authors describe the key features of RAGE and how it could have a role in AD pathogenesis. They also summarize experimental animal and clinical data that demonstrate the therapeutic effect of RAGE inhibition and consider what these findings mean for human disease.

Expert opinion: RAGE has multiple ligands, including Aβ, that are increased in AD brains. Inhibiting RAGE-ligand interactions without activating receptor signaling can reduce multiple pathological pathways relevant for AD. Several RAGE inhibitors and modulators are now being tested as therapeutics for AD. Recent Phase II studies have established the good safety and tolerability of TTP448 with some evidence of positive benefit at lower dose. This suggests that further studies are required.     

Optimal duration of therapy for catheter-related Staphylococcus aureus bacteremia: a study of 55 cases and review.

Over the last two decades, the optimal duration of therapy for catheter-related Staphylococcus aureus bacteremia has become the subject of controversy. A review of the literature revealed an occasional association between relapse of the infection and a short course of therapy (less than 10 days of iv antibiotic therapy). From records kept between 1983 and 1989 at the University of Florida's affiliated hospitals, we identified 55 patients with catheter-related S. aureus bacteremia. Nine patients (16%) developed acute early complications (e.g., endocarditis or osteomyelitis) while receiving antibiotics. The results of multivariate analysis showed that an early complicated course was characterized by fever and/or bacteremia that persisted for greater than 3 days after catheter removal (P = .02). The remaining 46 patients were followed up for at least 3 months. During follow-up, three of the 18 patients treated for less than 10 days with iv antibiotics developed relapsing septicemia, whereas none of the 28 patients treated for a longer period developed this condition (P = .05). Fever and/or bacteremia that persists for greater than 3 days after catheter removal and initiation of antibiotic therapy suggests an acutely complicated course requiring prolonged treatment. The duration of iv antibiotic therapy in uncomplicated cases should not be less than 10 days but need not be greater than 2 weeks.