Effect Of Addition Of Ag-embedded Nano-TiO₂ Antibacterial Agents On The Antibacterial Activity And Mechanical Properties Of The Alginate Impression Materials

Background: Today,in the 21 stcentury,Both in our country and abroad,In orthodontics,producing all kinds of maxillofacial or oral soft tissue and teeth models work,has been also cannot leave the use of dental impression material.Because of the advantage of the good liquidity,high plasticity,easy to use,the price is low and so on,alginate membrane materials is the most widely used in domestic.Dental impression material,however,were important factors can cause medical cross infection,some scholars study found that alginate membrane material has a retention and adsorption of the virus.Thus in modulus perfusion of the entire process,it is easy to cause between doctors and patients and the background mechanic mutual infection and spread of the virus.As a result,the preparation of high antibacterial properties of alginate membrane materials,reduce the occurrence of cross infection,has become the focus of many researchers.In recent years,In our country,some scholars consider adding antibacterial agent into the alginate impression materials in order to improve the antibacterial properties of impression material,due to the advantages of inorganic antibacterial agent itself,most of scholars try to add nano inorganic antibacterial agent in the material,But tied silver antibacterial agent combined with titanium dioxide photocatalytic antibacterial agent to join alginate impression materials in the literature at home and abroad are rare.Objective: This experiment will nano titanium dioxide antibacterial agent carrying silver（Ag-TiO₂）antibacterial agent added into the alginate impression materials,research the alginate impression material the antibacterial effect of oral some conditional pathogenic bacteria and some common physical properties under the condition of antibacterial itself will have corresponding change,to provide experimental basis for the application of materials in the future.Methods:1.In for（50 + 5）% relative humidity,under the condition of room temperature（23 + 2）℃,the temperature will be silver nano TiO₂ by mass fraction 0%,0.5%,1.0%,1.5%,2.0%,2.5%,3.0%,3.5% in alginate film printing materials,then preparation of candida albicans infection with all the samples,thermostatic cultivation by film thick stick method 45 min.Through experiments to detect join antibacterial antibacterial rate of alginate impression materials whether has antibacterial effect and the influence of adding amount of antibacterial effect2.Determination of fixed time: will a diameter of 30 mm,16 mm high metal mold on a piece of glass board,according to the different proportion of titanium oxide antibacterial silver nanoparticles add alginate impression material,fill in the mold,then every 10 seconds with a diameter of 6 mm,100 mm high organic glass rod test time,record from mixing to organic glass and sample with each time.3.The determination of deformation recovery: Concentration of specimens,according to the above points and eight groups,On the universal mechanical testing machine to test its height 30 seconds after 20% deformation（lasts 5 seconds）deformation recovery value.4.Compressive strain measurement: Concentration of specimens,according to the above points and eight groups.On the universal mechanical testing machine test,will produce a compressional stress loading by 0.01 N/was（for 30 seconds）increased to 0.1 N/was 30 seconds（keep）,20 mm alginate membrane material compressive strain.Results:1.The experimental results show that the experimental group compared with control group were statistically significant（p < 0.05）Within a certain range,with the increase of antibacterial dosage,alginate impression material antibacterial rate showed atrend of rising.And when the silver nano TiO₂ antibacterial agent adding amount was 2.0%,the sample of candida albicans antibacterial rate of more than 99%.2.With Ag-TiO₂ antibacterial agent,with the increase of adding amount of new antibacterial alginate impression material physical properties and the control group had no statistical difference（p > 0.05）,adding antibacterial silver nanoparticles on alginate impression materials have no obvious effect on physical performance.Conclusion:1.Add the silver nano TiO₂ antibacterial agent of alginate impression material-with the role of candida albicans,and the best adding proportion of 2.0% antibacterial agent.2.Add the titanium dioxide antibacterial silver nanoparticles alginate impression material itself have no obvious effect on physical performance.