Evaluation of the flexural mechanical properties of various thermoplastic denture base polymers.

This study evaluated the flexural mechanical properties of various thermoplastic denture base polymers (six polyamides, four acrylic resins, polyester, polypropylene, and polycarbonate) by three different testing conditions; specimens were tested in water bath at 37°C (Wet/Water, by ISO 20795-1), or in ambient air (Wet/Air) after being immersed in distilled water for 50 h, or after desiccation for 7 days (Dry/Air). The mean ultimate flexural strength (UFS) and flexural modulus (FM) for most products ranged from 27 to 61 MPa and from 611 to 1,783 MPa respectively, which failed to meet the minimum requirements of the international standard, except for polycarbonate (89 and 2,245 MPa). The mean UFS and FM values were ranked Dry/Air>Wet/Air>Wet/Water (p<0.05). In conclusion, the flexural mechanical properties of denture base polymers varied with the products and were significantly affected by the testing medium (air or water) and specimen conditions (wet or dry).

The Limitations of Thrombectomy with Solitaire™ AB as First-line Treatment in Acute Ischemic Stroke: A Single Center Experience.

OBJECTIVE: A self-expanding retrievable intracranial stent, such as Solitaire AB, is useful for mechanical thrombectomy, producing novel results in the treatment of acute ischemic stroke. On the other hand, difficult situations can arise after a thrombectomy when using as in first-line treatment. METHODS: This was a retrospective, single-center study of 23 patients with an acute ischemic stroke attributable to a large artery occlusion within the first eight hours from symptom onset. The occlusion sites were the T segment in five patients, proximal middle cerebral artery in six patients, distal middle cerebral artery in three patients, vertebral and/or basilar artery in five patients, proximal internal cerebral artery in one patient and tandem in three patients. All patients underwent a mechanical thrombectomy using the Solitaire™ stent system as the first-line treatment but required additional procedures due to the unsatisfactory results of a thrombectomy. RESULTS: Only six patients achieved complete recanalization by a thrombectomy using the Solitaire. Permanent stent deployment after the thrombectomy was performed in ten patients. Stent and balloon angioplasty was performed after a stent-based thrombectomy in six patients. Balloon angioplasty after thrombectomy was performed in one patient. CONCLUSION: Mechanical thrombectomy with the Solitaire™ stent as a first-line treatment can produce unfortunate results that will require additional procedures.

Correlation in the mechanical properties of acrylic denture base resins.

The aim of the present study was to measure various mechanical properties of acrylic denture base resins, including flexural modulus, flexural strength, fracture toughness, Barcol and Vickers hardness and their related properties, and to investigate correlations between different mechanical properties. Resin specimens were prepared according to manufacturers' recommended instructions. The mechanical properties were measured under specified standards. Data from the mechanical tests were examined using correlation tests. In general, the mean results for mechanical properties of each specimen group were differently ranked depending on the tested mechanical property. The flexural modulus value showed strong or reasonable positive correlation with those of proportional limit, flexural strength, and surface hardness. In contrast, fracture toughness revealed strong negative correlations with the flexural parameters and hardness values. Results of correlation tests for the different parameters can be used for estimation of mechanical performance of acrylic denture bases in clinical situation and for quality control purposes.

Cavernous hemangioma occurred between the trapezius and splenius capitis muscle.

Hemangiomas are the most common benign tumor of soft tissue. They are frequently seen on the trunk and extremities. In addition, most of them exist at the skin and subcutaneous layer, but fewer than 1% does in the intramuscular layer. For the diagnostic images of the intramuscular cavernous hemangioma, ultrasound (US), computed tomography (CT) and magnetic resonance imaging (MRI) are used currently. Multiple therapeutic methods are used, but surgical excision is considered as the most ideal treatment. We describe the recurred cavernous hemangioma occurred between the trapezius and splenius capitis muscle. The mass was well demarcated but scattered and infiltrated into the adjacent muscle layer, therefore, extensive resection was unavoidable. When determining a treatment regime for the hemangioma, it is essential to consider the size of the mass, cosmetic and functional aspects of the patient.

Usefulness of SPAIR Image, Fracture Line and the Adjacent Discs Change on Magnetic Resonance Image in the Acute Osteoporotic Compression Fracture.

OBJECTIVE: Osteoporotic compression fracture is an increasing issue in this community and its diagnosis depends on the magnetic resonance images (MRI). Although T1- and T2-weighted images (T1WI and T2WI) have high sensitivity and specificity, the fat suppression technique gives more clear delineation of this abnormalities. Accordingly, we re-evaluated its exact sensitivity and specificity for the imaging diagnosis of osteoporotic compression fractures in our cases. For additional information about the osteoporotic compression fractures, we evaluate the fracture lines, fluid sign and adjacent discs change on the MRI. METHODS: Retrospectively, total 85 patients who had been diagnosed with acute osteoporotic compression fracture were enrolled. They all had been underwent MRI including T1WI, T2WI and T2-Spectral Adiabatic Inversion Recovery (SPAIR) sequence. RESULTS: In this study, the incidence of high signal intensity on T2-SPAIR image was very high (0.9917). The fluid sign was seen in 56.7% on the SPAIR image. The fracture lines were more observed on the T2WI than T1WI (p=0.0062). The adjacent discs change on T2WI and T2-SPAIR image were higher than T1WI (p<0.001). CONCLUSION: For the acute osteoporotic compression fracture, T2-SPAIR image is the most specific sequence of the all sequences. The fluid sign is another suggestive finding when considered other studies. T2WI is more useful to find the fracture line than T1WI. Abnormal signal intensity on the adjacent discs may provide additional information for the acute osteoporotic compression fractures.

Comparative adaptation accuracy of acrylic denture bases evaluated by two different methods.

This study examined the adaptation accuracy of acrylic denture base processed using fluid-resin (PERform), injection-moldings (SR-Ivocap, Success, Mak Press), and two compression-molding techniques. The adaptation accuracy was measured primarily by the posterior border gaps at the mid-palatal area using a microscope and subsequently by weighing of the weight of the impression material between the denture base and master cast using hand-mixed and automixed silicone. The correlation between the data measured using these two test methods was examined. The PERform and Mak Press produced significantly smaller maximum palatal gap dimensions than the other groups (p<0.05). Mak Press also showed a significantly smaller weight of automixed silicone material than the other groups (p<0.05), while SR-Ivocap and Success showed similar adaptation accuracy to the compression-molding denture. The correlationship between the magnitude of the posterior border gap and the weight of the silicone impression materials was affected by either the material or mixing variables.