Surface Modification Of Expanded Polytetrafluoroethylene Membrane By Oxygen Plasma Immersion Ion Implantation And Its Antibacterial Adhesion Efficiency

Expanded polytetrafluoroethylene(ePTFE)is widely used to improve new attachment in GTR and bone augmentation in GBR. It is important for physical , chemical properties of barrier membranes in GTR and GBR. If the soft tissue flap is not tightly closed, ePTFE membrane maybe exposed to the oral environment, and bacterial adhering in materials may induce membrane related infection. The current method to overcome this shortage is to coat antibiotics in the surface of membranes, but it is unsatisfactory for releasing time and maintenance time of antibiotics. If ePTFE membrane has its own anti-adhesion ability of bacteria, it is a good news for GTR. Plasma immersion ion implantation (PIII) has been used to modify the surface of ePTFE membrane. The bacterial adhesion to the modified ePTFE was studied quantitatively. Oxygen gas was bled into the chamber, rf power was introduced to plasma discharge chamber to generate the oxygen plasma. In order to investigate the effects of PIII treatment, different sets of instrumental parameters were used. The modified ePTFE samples were investigated by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy and horizontal attenuated total fourier transform infrared spectroscopy (HATR-FTIR), and measured by the sessile drop method for static contact angles. The bacterial adhesion efficiency of staphylococcus aureus and streptococcus mutans to the modified ePTFE was studied quantitatively, and the accumulation of in vitro S. mutans biofilm on the modified ePTFE was investigated.The results indicated that:1. The morphological difference is observed of modified ePTFE. It revealed that PIII changed surface morphology, hydrophobicity and surface energy. More oxygen-containing, rougher, and more hydrophobicity surface were produced on ePTFE after long pulse, C-O and C=O is observed by XPS and HATR-FTIR, and C =O as the main oxygen-containing functional groups2. It manifested that long pulse PIII treated ePTFE significantly reduced the bacterial adhesion in vitro. There is no difference between short pulse PIII treated and blank gruops. The bacterial adhesion efficiency of the different ePTFE were different.3. After fluorescence-labeling, less bacteria in long pulse PIII ePTFE, and more bacteria in short pulse PIII ePTFE and virgin samples.Conclusions:The morphological difference is observed on modified ePTFE. It revealed that PIII changed surface morphology, property, hydrophobicity and surface energy of ePTFE. More oxygen-containing, rougher, and more hydrophobicity surface were produced on ePTFE after long pulse. A typical rough surface of colliculus and lower surface energy were also observed. It can reduce bacteria adherence and prevent to form biofilm.