In vitro degradation of a biodegradable polylactic acid/magnesium composite as potential bone augmentation material in the presence of titanium and PEEK dental implants.

OBJECTIVE: The aim of this study was to assess the degradation behavior by measuring the H2 release of a biodegradable composite consisting of a polylactic acid matrix reinforced with 30% wt. spherical magnesium microparticles (PLA/Mg) as potential bone augmentation material in combination with dental implants of either titanium or polyetheretherketone (PEEK) in order to evaluate the potential influence of the titanium dental implants on the corrosion behavior of the Mg particles within the PLA matrix.

METHODS: Three PEEK dental implants and three titanium dental implants were put into a central perforation of six PLA/Mg-discs. These samples were incubated at 37°C for 30days in McCoy's 5A modified medium and the H2 release was evaluated.

RESULTS: Between day 7 and day 16 the average H2 release per cm2 of the surface of the PLA/Mg-samples in combination with the titanium implants was significantly higher than that of the sample group combined with the implants of PEEK (3.1±0.4ml vs. 2.8±0.4ml). This significant difference disappeared afterwards, whereas the H2 release was highest at day 30 and amounted 3.5±0.7ml/cm2 for the group with the titanium implants and 3.2±0.8ml/cm2 for the group with the PEEK implants.

SIGNIFICANCE: Regarding the similar values of the degradation depending H2 release of the two implant material groups, the co-implantation of a PLA/Mg composite is not only possible with new metal-free implant materials such as PEEK, but also with conventional implants of titanium.