Modified Dental Composite for Bone Repair

Osteoporosis causes a decrease in bone density, along with deterioration of the bone’s microarchitecture at a faster rate than normal. This leads to increased risk of fractures, referred to as osteoporotic fractures which often occur in the spine. With age, the risk of fractures increases, due to reduction in bone mineral density as well as the increased rate of falls among the elderly. Bones weakened from metastatic cancer can also break or fracture. The fracture might happen with a fall or injury, but a weak bone can also break during everyday activities. Sudden pain in the middle of the back, for instance, is a common symptom of a bone in the spine breaking and collapsing from cancer(1).

 

One of the current treatments for osteoporotic fractures is vertebroplasty. Vertebroplasty is a procedure in which bone cement is injected into the fractured vertebrae for repair and stabilisation.

 

Polymethyl methacrylate (PMMA) is at present the most commonly used bone cement. However, there are several problems with using PMMA such as the mismatch of mechanical properties with that of surrounding bone. As well as the release of cytotoxic monomers and the high heat polymerisation of the material, resulting in reduced integration with the fractured bone. Numerous efforts have been made to develop bone composites with antibacterial properties and remineralising potential, however none of the experimental formulations to date have been ideal. Therefore, it is a necessity to improve bioactive, remineralising bone composites with anti-cancer properties.

 

Our bone composite consists of Monocalcium phosphate (MCPM) and polylysine (PLS). MCPM encourage remineralisation to allow for interaction with bone and PLS can inhibit bacteriophage development(2), due to its cationic nature (3).

 

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