Title: 0917 - Layered Double Hydroxides in Poly Methyl Methacrylate Based Materials


Bana Abdulmohsen (Presenter)
School of Dental Sciences, Newcastle University

Mark Franks, Barts and the London School of Medicine and Dentistry QMUL, London,
Corwin Hine, Barts and the London School of Medicine and Dentistry QMUL, London,
Mangala Patel, Barts and the London School of Medicine and Dentistry QMUL, London,


Objectives: To investigate the effects on water absorption/desorption properties, of incorporating Layered Double Hydroxides (LDH), into cold and heat cured Polymethyl methacrylate(PMMA) based resins. These systems have been developed for use as fluoride batteries for dental applications, since it has been shown that LDH can absorb and release fluoride ions repeatedly, from the environment.

Methods: LDH was incorporated (10%) into cold and heat cured PMMA materials and compared with those containing no LDH (control groups). Twenty discs (15×1mm2) were prepared (n=5each group) and weighed. Each specimen was immersed in 15ml deionised water (DW), weighed at regular intervals until equilibrated, and then removed from DW, placed at 23°C and weighed at regular intervals until equilibrated. The percentage equilibrium water uptake/loss, %solubility and diffusion coefficients (D) for uptake/loss processes were calculated. A nonparametric statistical test was used at a significant level of 0.05.

Results: The addition of 10%LDH in both cold and heat cured PMMA resins showed a significant increase in all water absorption/desorption parameters, apart from the cold cured PMMA system with respect to %solubility, which showed no significant difference to the unloaded system (Table 1).

Conclusions: Incorporation of 10%LDH in the two PMMA systems enhanced their water absorption/desorption characteristics. This enhanced uptake will potentially aid the release of fluoride ions (cariostatic action) once the PMMA systems have been charged with fluoride. Cold cured PMMA system with 10%LDH showed no significant increase in %solubility compared with the control.


Materials Cold cured PMMA-control Cold cured PMMA+10%LDH Heat cured PMMA-control Heat cured PMMA+10%LDH
Equilibrium uptake(%) 1.48±0.01 1.92±0.06 2.52±0.04 4.08±0.20
Equilibrium loss(%) 1.49±0.02 1.94±0.04 2.49±0.05 4.02±0.18
Solubility(%) 0.03±0.03 0.06±0.03 0.03±0.02 0.10±0.02
D-absorption×10-13(m2.sec-1) 7.46±0.57 6.33±0.20 5.67±0.27 3.76±0.47
D-desorption×10-13(m2.sec-1) 4.58±0.13 5.36±0.37 3.62±0.25 3.76±0.20

Disclosure Statement:
The submitter must disclose the names of the organizations with which any author have a relationship, the nature of the relationship, and the clinical or research area involved. The following is submitted: None