Bone cements

Question 1

Problems of PMMA cements

Answer 1

• non-resorbable
  stabilize fracture but impediment to bone healing
• lack of mechanical properties
• lack of direct contact to bone: encapsulated in fibrous tissue-aseptic loosening
• heating

Question 2

2 types of cements

Answer 2

apatite & brushite

apatite is stronger than brushite 20-50MPa vs 25MPa

Question 3

3 mechanisms for cement resorption

Answer 3

• active(cell-mediated) resorption
• passive(chemical dissolution) resorption
• hydrolysis

Question 4

Properties of a drug carrier

Answer 4

ability to incorporate a drug, retain it in a specific target site and deliver it progressively with time in the surrounding tissues