More recently, the development of bone mineral substitutes promises better integration into the osseous matrix as well as providing similar mechanical properties to the bone.
The most commonly used mineral substitutes for bone defect and trauma applications as implant coatings and defect fillers are thermally processed hydroxyapatite (HA) and tricalcium phosphate.
The most commonly used synthetic mineral substitutes for bone defect and trauma applications as implant coatings and defect fillers are hydroxyapatite cements, which have already undergone comprehensive animal testing and have also established themselves in many surgical procedures on human patients[ 18- 39].
These three minerals substitute in part for enstatite, albite (NaAlSi3O8, requiring three moles of silicon for one mole of sodium), and orthoclase feldspar (KAlSi3O8, requiring three moles of silicon for one mole of potassium), respectively.
A preliminary study of the possibility of using quartz powder (QP) as mineral admixture substituting Portland cement (PC) to resist elevated temperature and thermal shock was carried out.
Mineral bone substitutes have been in widespread clinical use for a number of years.
So drillers started adding dense minerals and substituting oil for water.
Animal manures and composts have shown in several trials to increase nutrient availability and to partly substitute mineral fertilizers (Goyal et al. 1999).
One of the possibilities in avoiding these problems, while keeping the advantages of oil-based muds, is to substitute mineral oils with biodegradable vegetable oils.
Such enriched composts partly substitute mineral fertilizer requirements (Adamtey et al. 2009), improve soil organic matter stocks, augument soil quality and most importantly prevent loss of nutrient N through volatilization (DeLaune et al. 2004; Steiner et al. 2010).
