First of all bone cement is absolutely different from any pmma tissue filler injections :-
Bone cements are supplied as a two-component system, consisting of a powder and a liquid, which are mixed and delivered to the implant site during the surgical procedure. The powder portion contains approximately 90% by weight polymer (PMMA) beads, the remainder is typically composed of benzoyl peroxide (BPO, free-radical initiator) and barium sulfate (BaSO 4 ) or zirconium dioxide (ZrO 2 ), both of which are radiopacifiers. The liquid portion contains three basic components: MMA (approximately 97 % by volume) monomer, N,N-dimethyl-p-toluidine (DMPT, free-radical activator), and hydroquinone (HQ, free-radical scavenger).
So with this conc. it has been used as we know in orthopedic surgery and dentistry.
So the only way if we need a harder pmma graft ---> the beads has to be closer to each other i.e. a higher conc. .
That was the reason why they made the highest conc. for pmma as a tissue filler 30% only and not higher than this - e.g. 40-45% pmma will be used for reconstruction of bone defect (e.g. frontal bone) :-
NewPlastic®, was developed in Porto Alegra, Brazil by Dr. Almir M. Nacul. Dr. Nacul is in clinical practice and is recognized as the inventor of Bioplasty (soft tissue augmentation with fillers) and has authored a medical textbook and many articles on soft tissue augmentation with PMMA. NewPlastic is the commercial name for a series of PMMA, products with microspheres of 40 to 60 microns, in different concentrations. These products are currently available as 2%, 10% and 30% concentrations of PMMA in a vehicle of 98% 90% and 70% methylcellulose, respectively. Dr. Nacul is also developing a 40-45% concentration for specific reconstructive applications where a denser implant is desired.
www.facialwasting.org/products.htm
As we know after few weeks post-pmma injection ---> our body will produce new collagen (i.e. scar tissues surrounding each bead) and the texture of the connections between these multiple scar tissues will be very important in determining the firmness of pmma graft .
So lets think about it this way e.g. 45% pmma conc. will give you a hard pmma-graft like a bone after few weeks i.e. the small multiple scar tissues forming around each bead are connected and fixed to each other so firmly like one piece and forming almost one big hard scar capsular tissue. So that means the connections and the bindings between these multiple small scar tissues are very important and the degree of firmness of the graft will depend on the texture of these connected fibrous tissues.
In regard of the other conc.\'s (2%,10@ and 30%) as a dermal filler will they become harder after a long period ?? I.e. will the connections and the bindings between the multiple small scar tissues surrounding the beads change in their texture and become harder later on and become almost like the 40-45% ?? The answer imo is NO ; the maturity and the end-stage of scar tissue formation is usually between 6-12 months in adults.
If you ask anyone who had penile pmma he will tell you the pmma feels softer in flaccid and firmer in erect and that is what my penile pmma (30% metacrill) still feels like after almost 4 years (actually this coming Oct. will be my 4th anniversary) and it had never changed or become harder.