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“Purpose: This study sought to determine whether the mechanical properties of titanium dental implants changed after exposure to bacteria. Materials and Methods: Two strains of bacteria (Streptococcus sanguinis and Lactobacillus salivarius) were used in the study. The adhesive properties of the two strains were investigated as follows. Titanium implants were placed in bacteria broth, seeded with the two bacteria strains, Dibutyryl-cAMP and left in the broth for I or 3 months. Another group of titanium implants was immersed in artificial saliva at 37 degrees C for 3 months. Ten implants in each
group were tested in 37 C artificial saliva to evaluate their mechanical flexural strength and fatigue life. Results: The bacterial cultures grew quickly on titanium surfaces. After 1 month of bacteria culture in vitro, the bacteria had produced corrosion pits on the titanium surfaces. After 3 months of bacterial culture, a 7% decrease in the flexural strength of the implant samples and a decrease of 15% in the number of cycles to failure by fatigue were seen versus implants not exposed to bacteria. Conclusions: These results
demonstrate that, in physiologic conditions in vitro, bacteria selleck products have the capacity to produce a pitting corrosion phenomenon on exposed titanium surfaces, leading to a significant deterioration in the mechanical properties of the implant. It is therefore logical to conclude that bacteria may produce corrosion that reduces the useful life of dental implants. INT J ORAL MAXILLOFAC IMPLANTS 2012;27:64-68″
“In vivo imaging of engraftment and immunorejection of transplanted islets is critical for further clinical
development, with (1)H MR imaging of superparamagnetic iron oxide-labeled cells being the current premier modality. Using perfluorocarbon nanoparticles, we present here a strategy for non-invasive imaging of cells using other modalities. To this end, human cadaveric islets were labeled with rhodamine-perfluorooctylbromide (PFOB) EPZ5676 nanoparticles, rhodamine-perfluoropolyether (PFPE) nanoparticles or Feridex (R) as control and tested in vitro for cell viability and c-peptide secretion for 1 week. (19)F MRI, computed tomography (CT) and ultrasound (US) imaging was performed on labeled cell phantoms and on cells following transplantation beneath the kidney capsule of mice and rabbits. PFOB and PFPE-labeling did not reduce human islet viability or glucose responsiveness as compared with unlabeled cells or SPIO-labeled cells. PFOB-and PFPE-labeled islets were effectively fluorinated for visualization by (19)F MRI. PFOB-labeled islets were acoustically reflective for detection by US imaging and became sufficiently brominated to become radiopaque allowing visualization with CT.