Bioactivity and successful bone formation in silicon-substituted hydroxyapatite bone grafts were investigated by using scanning electron microscopy and electron dispersive x-ray spectroscopy. Areas of bone formation have been detected in scanning electron microscopy; and. arranged lamellar collagen has been observed. 20. https://www.roneverhart.com/Modern-Rectangular-Keyed-Entry-Pocket-Door-Emtek-2113/