bonecement.com

Biomet Cement and Cementing Systems


Bone Cement

Components

Bone cements consist of two primary components: a powder consisting of copolymers based on the substance polymethyl methacrylate (PMMA), and a liquid monomer, methylmethacrylate (MMA). These two components are mixed at an approximate ratio of 2:1 to form a polymethyl methacrylate cement.

Powder

e.g. pouch

Liquid

e.g. ampoule

Polymer

PMMA

Monomer

MMA

Starter

BPO

Initiator

DmpT

Radiopacifier

ZrO2/BaSO4

Inhibitor

HQ

Antibiotics

  

Colouring agent

  
       

Exposure to light or high temperatures can cause premature polymerization of the liquid component. Hydroquinone therefore is added as a stabiliser or inhibitor to prevent premature polymerization.A starter, di-benzoyl peroxide (BPO), is added to the powder, and an initiator, mostly N,N-dimethyl-p-toluidine (DmpT), is added to the liquid to encourage the polymer and monomer to polymerise at room temperature (cold curing cement).

In order to make the cement radiopaque, a contrast agent is added. Commercially available cements use either zirconium dioxide (ZrO2) or barium sulphate (BaSO4). Zirconium dioxide is one hundred times less soluble than barium sulphate and has less effect on the mechanical properties of the cement.

Chlorophyll is added to Biomet Europe cements, the colour makes the cement more easily visible in the operating room, especially during revision procedures. The powder component in our antibiotic-loaded bone cement additionally contains an antibiotic (such as gentamicin) or a combination of antibiotics (such as gentamicin and clindamycin).