“
“ObjectivesThe goal of the present study was to develop a theoretical analysis of errors in implant position, which can occur owing to minute registration errors of a reference marker in a cone beam computed tomography volume when inserting an implant with
a surgical stent.\n\nMaterial and methodsA virtual dental-arch model was created using anatomic data derived from the literature. Basic trigonometry was used to compute effects of defined minute registration errors of only voxel size. The errors occurring at the implant’s neck and apex both in horizontal as in Compound C vertical direction were computed for mean 95%-confidence intervals of jaw width and length and typical implant lengths (8, 10 and 12mm).\n\nResultsLargest errors occur in vertical direction for larger voxel sizes and for greater
arch dimensions. For a 10mm implant in the frontal region, these can amount to a mean of 0.716mm (range: 0.201-1.533mm). Horizontal errors at the neck are negligible, with a mean overall deviation of 0.009mm (range: 0.001-0.034mm). Errors increase with distance to the registration marker and voxel size and are affected by implant length.\n\nConclusionOur study shows that minute and realistic errors occurring in the automated registration of a reference object have an impact on the implant’s position and angulation. These errors occur in the fundamental initial step in the long planning chain; thus, they are critical INCB028050 and should be made aware to users of these systems.”
“We investigated whether administration of estradiol to male mice augments mobilization of bone marrow-derived
endothelial progenitor cells (EPC) and incorporation into foci of neovascularization after hind-limb ischemia, thereby contributing to blood flow restoration. Mice were randomized and implanted with placebo pellets or pellets containing low-dose estradiol (0.39 mg) or high-dose estradiol (1.7 mg). Hind-limb ischemia was induced by unilateral resection of the left femoral artery 1 week after pellet implantation, DMH1 then EPC mobilization and functional recovery was evaluated. EPC recruitment was assessed in mice transplanted with bone marrow from transgenic donors expressing beta-galactosidase driven by the Tie-2 promoter. EPC culture assay performed 2 weeks after pellet implantation revealed a significantly greater (p < 0.05) number of circulating EPCs in the high-dose estradiol group than in the low-dose estradiol and placebo groups. At 3 and 4 weeks after induction of hind-limb ischemia, perfusion was significantly greater (p < 0.05) in high-dose estradiol mice than in mice implanted with the low-dose estradiol or placebo pellets.