Polymethylmethacrylate bone cements and additives: A review of the literature

Table 1 Exothermic activity of polymethylmethacrylate mixed with nano-MgO (12.8 nm) vs polymethylmethacrylate control[25]

	1 s	1 min	2 min	10 min	107 min
PMMA (°C)	44.98	45.82	50.10	52.5	47.85
PMMA and nano-MgO (°C)	39.65	40.36	46.99	48.85	44.10

PMMA: Polymethylmethacrylate.

Table 2 Diametral tensile strength of polymethylmethacrylate and MMA:AA: MA co-polymer mixtures[47]

PMMA	MMA:AA:AMA	MMA:AA:AMA	Tensile strength
quantity (g)	quantity (g)	ratio	(Mpa)
20	0	-	31.3 ± 9.0
19	1	80:20:10	39.3 ± 3.0
17	3	80:20:10	36.2 ± 4.7
19	1	70:30:10	33.1 ± 4.2
17	3	70:30:10	26.6 ± 6.1

PMMA: Polymethylmethacrylate.

Table 3 Summary of polymethylmethacrylate bone cement additives

Additive	Summary
Gentamicin	Reduces post-operative infection rates. Powdered format (2/60 g or 2/40 g) shows no significant impact on mechanical strength, however increased gentamicin concentration decreases mechanical strength
Vitamin E	Improves cement cytocompatibility and reduces peak temperature. 10% vitamin E concentration does not significantly affect mechanical strength. Increasing concentrations associated with increased setting time and decreased mechanical strength
Polymer MMA:AA:AMA	Reduces bone cement shrinkage and improves fracture toughness. 80:20:10 significantly improves mechanical strength vs control
NanoMgO and NanoBaSO4	Improves osteoblast adhesion, nanoMgO (12.8 nm) minimizes tissue necrosis and nanoBaSO4 (100 nm) improves mechanical strength
Barium sulfate	Allows radiological identification of cement. 10% concentration is not associated with significant decrease in mechanical strength vs control. As concentration increases, mechanical strength decreases
Chitosan nanoparticles	In vitro studies show significant antibacterial activity against S. aureus and S. epidermidis with no significant difference in cytoxicity and mechanical strength vs control PMMA
Silver nanoparticles	AgNP (1%) has strong and continued antibacterial activity (against A. baumannii, P. aeruginosa, P. mirabilis and S. aureus) but with reduction in mechanical strength. Nanosilver (5-50 nm) has antibacterial activity against S. epidermidis, MRSE and MRSA with no significant difference in cytotoxicity vs control

PMMA: Polymethylmethacrylate; MRSE: Methicillin-resistant S. epidermidis; MRSA: Methicillin-resistant S. aureus.