Preparation And Properties Of Poly (Ether Ether Ketone) Bioactivite Dental Composite

Poly(ether ether ketone)(PEEK), a semicrystalline high performance thermoplastic, hasexceptional mechanical properties, biocompatibility, resistance to chemical and radiationdamage, compatibility with various kinds of reinforcing agents and high-temperaturestability.The excellent characteristics make PEEK used as spine cases. In dentistry, littleattention was devoted to PEEK, mainly due to (1) the poor bonding property to dentalmaterials （adhesive or resin cement），(2) without radio opaque. Acid etching, laser treatmentand plasma techniques are often used to modify engineering plastics’ surface for improvingbonding property, however, they are difficult to be applied in clinical practice due to thetechnological uncertainty. In addition, dental implantation develops quick these years, implantmaterial should be with great bioactivity. Little study has been carried out on the developingPEEK dental material, our work enhancing the bonding property, radio opaque property andbioactivity, make it more suitable for dental application.First, we prepared a series of PEEK/BGF composites with different BGF content anddifferent BGF particle size. As a widely used material in dentistry, the biocompatibility andbiological safety of barium-containing glass filler (BGF) have been proved by variousexperiment and long-term clinical application. Compounding BGF with PEEK is a physicalprocess that would not change any chemical structure of PEEK. In consequence, the properbiocompatibility of PEEK-BGF composites is foreseeable. It could be seen that the additionof BGF enhanced modulus, strength and hardness of the composites compared with purePEEK. The barium-containing glass (BGF) reinforcement and pretreatment methods effects toshear bonding strength (SBS) of PEEK to resin cement were investigated. The shear bondstrengths were dramatically increased by BGF reinforcement. In addition, the X-ray opaqueproperty is also enhanced,20%of BGF containing fulfill the demand of clinic demand.Although the BGF reinforcement could great reduce the coefficient of friction, wear rate is not improved.Second, various amounts of PEEK/BGF/GF composites were prepared by twin screw,and BGF particles are well dispersed in PEEK matrix, which are confirmed by the SEMresults. In previous report, PEEK composites had been associated with load-bearing implantmaterials. The inorganic particle reinforcement would greatly improve the mechanicalbehavior of PEEK and significantly decrease the thermal expansion coefficient, makingPEEK more suitable for dental application. Various inorganic materials have been used asreinforcing components and have made up the bulk component of the composites and resincement, such as silica, zinc oxide, and so on. In addition to reinforcing fillers, barium andstrontium are often incorporated to silicon oxide particles, which can add x-ray opacity tofacilitate radiological monitoring of PEEK composites in vivo. Glass fiber is one of the mostcommon reinforcing filler, it can give the material a high strength, modulus，low wear rate. Sodifferent ratios of glass fiber and BGF was introduced into the PEEK to prepare ternarycomposite materials. The results show that the ternary composite with high modulus andstrength, the glass itself has a high rigidity and wear resistance, ternary composites still has alow coefficient of friction. The results show that the ternary composite with high modulus andstrength, the glass itself has a high rigidity and wear resistance, high BGF and low glass fibershows the best wear performance.Hydroxyapatite/PEEK composites were prepared by twin screw, the introduction ofHydroxyapatite do not enhanced bioactivity of the composite. By the linkage of silanecoupling agent, light cured coating was formed on poly(ether ether ketone)/barium-containing glass filler (PEEK-BGF) composite surface. The coating was composed ofbioactive nano hydroxyapatite (nHA) and methacrylate light cure resin. SEM and XPS wereused to analyze the topography and elements distribution feature of the sample surface, andthe bonding strength was tested by the universal testing machine. Rat osteoblasts cells werecultured on the material surface. The total protein concentration test and alkaline phosphatase(ALP) assay of osteoblasts were performed to examine the bioactivity of new type light curednano hydroxyapatite/polymethacrylate（nHA/PMMA）hybrid coating. The results showed thatthe nHA hybrid coating could form a rough morphology on the composite surface. With theincrease of nHA content, the bioactivity of the coating is enhanced.