Steroids such as prednisone, cortisone or hydrocortisone are members of a class of hormones called glucocorticoids. Their most important long term use side effects as they relate to implants and grafting are the following:
1- Inhibition of bone formation
2- Suppression of calcium absorption
4- Delayed wound healing and
5- Increased risk of infection
This means that long term use of glucocorticoids can adversely affect the mineralization of a bone graft and postoperative healing including a higher risk of infection.
Patients taking long term glucocorticoids should consult with their physician before undergoing bone grafting or implant surgery.
Good luck! Dr. Carlos Boudet
Steroid isolation , depending on context, is the isolation of chemical matter required for chemical structure elucidation, derivitzation or degradation chemistry, biological testing, and other research needs (generally milligrams to grams, but often more  or the isolation of "analytical quantities" of the substance of interest (where the focus is on identifying and quantifying the substance (for example, in biological tissue or fluid). The amount isolated depends on the analytical method, but is generally less than one microgram.  [ page needed ] The methods of isolation to achieve the two scales of product are distinct, but include extraction , precipitation, adsorption , chromatography , and crystallization . In both cases, the isolated substance is purified to chemical homogeneity; combined separation and analytical methods, such as LC-MS , are chosen to be "orthogonal"—achieving their separations based on distinct modes of interaction between substance and isolating matrix—to detect a single species in the pure sample. Structure determination refers to the methods to determine the chemical structure of an isolated pure steroid, using an evolving array of chemical and physical methods which have included NMR and small-molecule crystallography .  : 10–19 Methods of analysis overlap both of the above areas, emphasizing analytical methods to determining if a steroid is present in a mixture and determining its quantity. 
Cholesterol - Cholesterol is a major precursor of cholesterol ester, bile acids, and steroid hormones and is a component of plasma membranes. It is a necessary component of all cell membranes. It is the precursor to all steroid hormone (including estrogen , testosterone , cortisol , and vitamin D ). It is the leading organic molecule in the brain and is needed for brain function. However, too much cholesterol in the bloodstream can be unhealthy, it builds up in the artery wall and can lead to the signs and symptoms of coronary heart disease.