Wear testing of composite, gold, porcelain, and enamel opposing a removable cobalt-chromium partial denture alloy.

PURPOSE: Eighty percent of all removable partial denture (RPD) frameworks are fabricated from cobalt-chromium (Co-Cr) alloys. The advantages of this material include low density and high modulus of elasticity, hardness, and strength. Hardness is of particular concern when related to excessive wear of natural teeth or restorative materials. The purpose of this study was to compare the differences in localized wear among enamel, composite, gold, and porcelain by a Co-Cr alloy RPD. MATERIALS AND METHODS: Thirty-two polished specimens were prepared and positioned in an acrylic-filled custom fixture for testing. Upon optical examination, the highly polished surfaces of the specimens were scratch-free. They were mounted into a water bath fixture and subjected to 250,000 cycles in a wear simulator equipped with a conical Co-Cr stylus specially fabricated to produce localized wear. A posttest was generated, and the profiles were fitted and evaluated using software. The total volume loss and depth of the wear facet on each specimen were analyzed using ANOVA and Fisher's PLSD test. RESULTS: Volume loss (mm3) was as follows: composite, 0.110; gold, 0.021; enamel, 0.008; porcelain, 0.006. The maximum depths (microm) were: composite, 92; gold, 22; enamel, 13; porcelain, 17. Resin composite had significantly higher values (p < 0.0001) of volumetric loss and maximum depth than the other materials. No significant differences were detected among volumetric loss and maximum depth values for gold, enamel, and porcelain. CONCLUSIONS: Significant differences for mean wear volume loss and maximum depth were found between composite and gold, enamel, and porcelain. Enamel proved to be wear resistant to the Co-Cr alloy. CLINICAL IMPLICATIONS: porcelain and gold appear to be good options for occlusal surfaces opposing a Co-Cr alloy; however, the test composite was not found to be a recommended option.

Disseminated intravascular coagulopathy: manifestations after a routine dental extraction.

Clinical signs and symptoms of acute disseminated intravascular coagulopathy (DIC) include bleeding from body orifices, such as the nose, mouth, or ear, bleeding from an intravenous (IV) site, areas of ecchymosis, or blood in the urine or stool. The underlying disease triggering DIC usually determines the clinical presentation. However, patients with chronic DIC (compensated DIC) may possess subclinical signs and symptoms, and the bleeding disorder may only be identified through laboratory findings. In this compensated form, the triggering factor is exposed slowly and in small amounts (seen in malignancies and vasculitis), allowing replenishing of the augmented factors by the liver, adequate reticuloendothelial clearance of fibrin degradation products, and increased production of platelets, which prevent secondary fibrinolysis and the signs of bleeding. 1,4 We report a case of an 82-year-old male who presented to the emergency room 24 hours after a routine dental extraction with bleeding from the tooth socket, severe hypotension, and presence of ecchymosis on his chest. Clinical and radiographic exam revealed multiple thoracic and abdominal aortic aneurysms, as well as infrarenal and iliac aneurysms, continuous oral hemorrhage, and a unique presentation rarely documented in the literature: a bleeding tooth socket as the initial clinical sign and presentation of DIC.