Experimental Study On Ceramic-filled Plastic Material Of Orthodontic Bracket

Experimental study on ceramic-filled plastic material of orthodontic bracketObjectiveBracket is an important part of the fixed appliance, the orthodontic force contribute to the teeth by brackets. In clinic, the brackets need to be favourable mechanical function, esthetic, high performation, hygien and comfortable. The early bracket is plastic bracket, this bracket is made by PC, a thermoplasticity polymer whose characters are nonfixform,insipidity, nonsmell, asepsisand and hyaloid. But the plastic brackets can not stay a long time in clinic for its discoloration, hign friability, disrupt easily with stress and hypo-intensity in stickiness. These years, as the development of the stomatology materials, the study and exploitation for the plastic bracket became active. This experiment intend to study the reshaping of the PC, and choose inorganic slurry such as porcelain cement, antioxidant, toughening agent and coupling agent, then to increase the rigidity, ducktility and antioxygen voltilism of the PC. At that time, the disadvantages of the plastic bracket can be solved and the clinic demands can be satisfied.Materials and MethodsThe preparation of the ceramic composite grain power: miscebene the PC, porcelain cement, coupling agent, toughening agent, and auxiliaries in the hign speed mixer, then add the mixed materials to the TSE-30 type ambi-screw forcer to carry out liquating and extruding. After draw stick, cool down and cut grain, we can get the grain power of the ceramic composite.Formulating of recipe about the choice of the coupling agent: select three coupling agents such as the KH550, KH560, NDZ201 as contrast to run the experiments no. 1 to 6.Formulating of recipe about the choice of the toughening agent: select three toughening agents such as the KT-15, KT-17 and 2330 as contrast to run the experiments no. 7 to 21. Formulating of recipe about the choice of the porcelain cement dosage: in order to study the influence of the dosage of the ceramic power to the composite efficiency, the experiment no. 22 to 37 were carried out.The preparation of the standard specimen: according to the country defined unity standard, we can get the efficiency test standard specimen by putting the reshaping power into the WG-100 type injection machine. Then the determination of the melt flow rate and the test of the mechanics efficiency were carried out.ResultsTreat the surface of the porcelain cement with the silane coupling agent, whose effect in enhancing the efficiency of the PC composite is surpass the titanic-oate coupling agent. The optimization of the silane coupling agent is KH560; whose proper dosage is 0.9%.Add the toughening agents KT-15, KT-17and 2330 separately into the PC composite, after comparation, the result is the toughening agent can raise the impact strength and fragmentation extensibility of the PC composite obviously, besides, with the increasement of the KT-17 dosage, both the impact strength and fragmentation extensibility present an upgrade tendency. while the tensile strength and the bending strength just expenses partly. In a word,the mechanics effect of the KT-17 is better than the KT-15 and 2330, and the liquate index number decrease parum. When the addition of the KT-17 is 5%, the every efficiency of the PC composite is excellent.As an enhancement material, the porcelain can raise the mechanics efficiency of the ceramic enhanced PC composite efficaciously. When the porcelain cement addition is 15%, the mechanics efficiency of the PC composite is the best.ConclusionsThe PC composite prepared with KH560 as coupling agent, KT-17 as toughening agent and the porcelain cement as furniture possess favourable combined efficiency. The bracket materials made by the ceramic enhancement PC composite can satisfy the desire of the mechanical function of the brackets.