The objective of this study was to determine whether clinically significant ocular trauma can be induced by a survivable isolated primary blast using a live animal model. Both eyes of 18 Dutch Belted rabbits were exposed to various survivable low-level blast overpressures in a large-scale shock tube simulating a primary blast similar to an improvised explosive device. Eyes of the blast-exposed rabbits (as well as five control rabbits) were thoroughly examined before and after blast to detect changes. Clinically significant changes in corneal thickness arose immediately after blast and were sustained through 48 h, suggesting possible disruption of endothelial function. Retinal thickness (RT) increased with increasing specific impulse immediately after exposure. Intraocular pressure (IOP) was inversely correlated with the specific impulse of the blast wave. These findings clearly indicate that survivable primary blast causes ocular injuries with likely visual functional sequelae of clinical and military relevance.

No abstract

Background: Ridge preservation is performed by placing a biocompatible product, following tooth extraction, to maintain bone volume. However, current ridge preservation therapies do not always maintain the volume required for future implant placement. Variations in surgical technique and material selection contribute to determining clinical outcomes. The wide variety of grafting materials available and conflicting efficacy reports make selecting the appropriate graft materials challenging. To investigate how different commercially available ridge preservation products might perform clinically: Helistat (collagen control) (Material 1), OsteoGen Plug (Material 2), Bio-Oss Collagen (Material 3), and J-Bone (native bone) (Material 4) were evaluated.Methods: These products underwent field emission scanning electron microscopy, microcomputed tomography, helium pycnometry, and infrared spectra analysis. Human osteosarcomas were incubated on products and proliferation was monitored with CCK-8 and visualized with confocal microscopy. Scaffold osteoconductivity was evaluated through the cellular production of proteins osteocalcin, osteonectin, and osteopontin.Results: Results indicated that products varied in porosity and pore interconnectivity. Although Material 3 was chemically similar to Material 4, Material 2 demonstrated significantly better biocompatibility. Functionally, Material 1 and Material 2 elicited higher osteonectin release than Material 3 and Material 4 which suggests the latter products suppress endogenous osteonectin secretion. Furthermore, osteopontin secretion was minimal for all products, while osteocalcin was elevated. This seems to suggest that high levels of mineralization might be deleterious for bone regeneration. Conclusions: Although all products are marketed as effective preservation products, the results demonstrated high variability in physical, chemical, and biological effects; however, this study suggests a product with higher ratio of collagen

No abstract