Study On The Preparation And Properties Of Flurine-containing Hydrophobic Film Coating On Denture Base

Tooth loss by various causes is a common disease in the dental field. Complete denture and removable partial denture are the main methods of the repair of tooth loss. As an integral part of the denture, denture base is used to repair soft tissue loss and to conduct and distribute Jaw force to the remaining alveolar crest. PMMA is currently an common material of denture base. After wearing the denture, microorganisms, especially species which are involved in caries, periodontal disease and denture stomatitis, will be conglutinate to the denture's coarse surface and create bacterial plasue. After that, bacterial plasue keeps growing and be calcified to dental deposits . This will cause neopathies such as Inflammation of oral mucosa, caries and alveolysis.In order to restrain the bacterial plasue's aggradation on the denture base surface, common measures are used, including physical methods, chemical methods, base surface treatments and adding antibacterial agent into the base. These methods are helpful to restrain or sterilizing bacillis. However, these methods mentioned above have their shortages, which makes discovering and seeking a new method that have sound cleaning and antibacterial effect, is still the directions for the future researches. Researches show that materials with high hydrophobicity have the ability of self-cleaning. Many studies indicate that astilboides tabularis have Slightly rough surface, and the fractal structures that formed by micro structures and nanostructures could make the surface super hydrophobic. This research uses the multiple hybrid approach in Sol-gel method, gains a stable fluorine-containing hydrophobic Silicone hybrid coating, and cover the coating onto the denture base, to improve its self-cleaning ability and anti-pollution ability. In the experimentation, TEOS is putted into Solvent ethylene glycol ether. On the certain temperature, use acid as catalyzer to hydrolyze for 15 hours . Then , put the ether containing siloxane-based three-dimethylsiloxane,ageing and get silicone hybrid precursor sol. Next, introduce Fluorine-containing compounds into precursor that produced from Sol-gel,we can gain a stable fluorine- containing hydrophobic Silicone hybrid film coating.Cover the organic precursors and hybrid fluorinated silicone film coating onto the substrate, use SEM to observe their surface, and use infrared spectroscopy to test their structures and performances. Use UV spectrophotometer to evaluate their retias'transparences. In the same time, select 8 types of liquid, including distilled water, normal saline, Artificial saliva, Coca cola, Pepsi, red wine and Dry red wine l . Put 4μl drops of each type of the liquid to the center of the organic precursors and hybrid fluorinated silicone coating's surface. Measure the contact angles and collect contact angles'pictures.Observing through unaided eyes, organic precursors and the new fluorine-containing hydrophobic coating are both transparent, smooth and without unusual things at the edges. Observing through the SEM, the surfaces are smooth, with no chap or tuber, but with sound properties. The infrared spectrometer test confirmed that the Hydrolytic condensation of Ether-based trimethoxysilane and TEOS is sufficient, and 1H,1H,2H,2H- 17 perfluoroalkyl alkyl silane Trimethyl oxygen has been successfully introduced into the precursor . The New fluorine- containing hydrophobic coating is clear and transparent. In the UV spectrophotometer testing, visible light can get through effectively, and there is no big aggregation in the Hybrid film, and it does not affect the denture base's simulation of color. Contact angle measuring instrument is used to measure the contact angle of 8 liquid contact with the hydrophobic fluorine-containing organic silicon hybrid film and with the general denture base surface. Statistical Analysis shows that there is a dramatic height difference for each type of liquid(P<0.001).In this research, the stable fluorinated alkanes is introduced into the crosslinked network structure that created by TEOS和GPTMS Sol-gel, and hydrolysis condensation creates film structure with good performance. After that, the coat is spreaded on the general denture base surface. The testing result shows that the contact angles between fluorine-containing hydrophobic coatings and different types of liquid are bigger than these between control group of denture bases and liquid. This result will highly improve bases'self-cleaning and anti-dirty abilities. The thickness that hydrophobic self-cleaning coating covered on the base surface is just between 10～30 micron, having slight impact on the base's general mechanical properties. Additionally, the coating is transparent, which means it will not affect the base's simulation of color, but can block the air holes and cranny that created in the curing process of conventional plastic base, and can also cover the polishing dead zones, such as O-space and outreach gap, to decrease bacterial attachment possibility . Furthermore, the base will be given certain self-cleaning and antisepsis ability, which means the material's aging resistance performance will be improved.Conclusions:①the hybrid organic silicon precursor created by Sol-gel method can react completely with various components of the fluorine-containing hydrophobic coating, to create space cross linked structures.②the fluorine-containing hydrophobic coating have good surface performance. The retia has no aggregation, is clear and transparent.③the contact angles between the fluorine-containing hydrophobic coating and various types of liquid are bigger than that between the control group of base resin film and that liquid. And the coating's hydrophobic ability with pigment-rich regular drinks is evidently stronger than denture base resin, which illustrates that the fluorine-containing hydrophobic film coating have sound anti-dirty ability.