437
However , implants made of these materials are usually much stiffer than natural bones , leading to stress shielding - a major source for bone resorption and eventual failure of such implants .
 application: implants; concept or principle: materials; machanical property: stress shielding; application: source; concept or principle: bone resorption; concept or principle: failure; application: implants
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: manufacturing standard, machanical property, manufacturing process, material, engineering feature, process parameter, machine or equipment, application, process characterization, enabling technology, biomedical, concept or principle 
Text: {0} 
Answer:
 application: implants; concept or principle: materials; machanical property: stress shielding; application: source; concept or principle: bone resorption; concept or principle: failure; application: implants