Investigation of flexural strength and cytotoxicity of acrylic resin copolymers by using different polymerization methods

PURPOSE: The aim of this study was to appraise the some mechanical properties of polymethyl methacrylate based denture base resin polymerized by copolymerization mechanism, and to investigate the cytotoxic effect of these copolymer resins. MATERIALS AND METHODS: 2-hydroxyethyl methacrylate (HEMA) and isobutyl methacrylate (IBMA) were added to monomers of conventional heat polymerized and injection-molded poly methyl methacrylate (PMMA) resin contents of 2%, 3%, and 5% by volume and polymerization was carried out. Three-point bending test was performed to detect flexural strength and the elasticity modulus of the resins. To determine the statistical differences between the study groups, the Kruskall-Wallis test was performed. Then pairwise comparisons were performed between significant groups by Mann-Whitney U test. Agar-overlay test was performed to determine cytotoxic effect of copolymer resins. Chemical analysis was determined by FTIR spectrum. RESULTS: Synthesis of the copolymer was approved by FTIR spectroscopy. Within the conventional heat-polymerized group maximum transverse strength had been seen in the HEMA 2% concentration; however, when the concentration ratio increased, the strength decreased. In the injection-molded group, maximum transverse strength had been seen in the IBMA 2% concentration; also as the concentration ratio increased, the strength decreased. Only IBMA showed no cytotoxic effect at low concentrations when both two polymerization methods applied while HEMA showed cytotoxic effect in the injection-molded resins. CONCLUSION: Within the limitations of this study, it may be concluded that IBMA and HEMA may be used in low concentration and at high temperature to obtain non-cytotoxic and durable copolymer structure.

Hemostatic efficacy of Ankaferd Blood Stopper [R] in a swine bleeding model

The purpose of this study was to show the hemostatic effect of spray, solution and tampon forms of Ankaferd Blood Stopper[R] [ABS], a unique medicinal plant extract historically used as a hemostatic agent in Turkish folklore medicine, in a porcine bleeding model. Two 1-year-old pigs were used as bleeding models for superficial and deep skin lacerations, grade II liver and spleen injuries, grade II saphenous vein injury and grade IV saphenous artery injury. Spray, solution or tampon forms of ABS were applied after continuing bleeding was confirmed. The primary outcome was time to hemostasis. Volume of blood loss was not measured. The pigs were euthanized at the end of the experiment. Spray or direct application of ABS solution resulted in instant control of bleeding in superficial and deep skin lacerations as well as puncture wounds of the liver. A 40-second application of ABS tampon was sufficient to stop bleeding of skin lacerations, while 1.5- and 3.5-min applications were used to control hemorrhage from the saphenous vein and artery, respectively. No rebleeding was observed once hemostasis was achieved. However, repeated applications of ABS solution and tampon were only temporarily effective in the hemostasis of spleen injury. The data showed that ABS was an effective hemostatic agent for superficial and deep skin lacerations and minor/moderate trauma injuries in a porcine bleeding model

Cerebral dural sinus obstruction caused by parasagittal meningioma presenting as pseudotumor cerebri

Acase of thrombosis of the superior sagittal sinus [SSS] and straight sinus caused by a parasagittal meningioma presenting as pseudotumor cerebri [PTC] is presented along with a review of the literature. Tumoral occlusion of the venous sinuses is arare condition but potentially life-threatening and must be kept in mind in the diff e rential diagnosis of PTC