Study On Bacteriostatic Effecacy And Dismensinal Accuracy Of Alginate Impression Masterials

There emerged 40 kinds of viruses never seen before in recent 30 years due to the environmental evolution. In recent 10 years, the latest flu greatly hurt the human being health. Since 1970s, the disinfecting method of dental impression materials has drawn a lot of attentions from foreign scientists who did the corresponding researches. But the scientists draw different or even contrary conclusions. So far, there is not a complete set of generally accepted disinfecting method for the dental impression materials in the world. The most popular disinfecting method, immersing disinfection, will make the alginate impression deformed and damage the detail of impression surface. The application of the method is limited due to its complicated operation and erosion. Furthermore, the emission of disinfector will do potentially harm to human being body. In order to seek an effective disinfecting method, the first part of this paper concentrated on the antibacterial effect against usual oral bacteria based on putting disinfector into impression materials, the rest part of the paper concentrated on the comparison between traditional disinfecting method and my method based on putting disinfector into impression materials and dental stoneThe results are showed below:1. Appling different concentrations of bromogeramine as disinfector, observe the antibacterial effect of impression materials mixed with different concentrations of bromogeramine With increasing the concentration (0.05%, 0.1%, 0.2% and 0.4%) of, bromogeramine the inhibition zone increases. However, the inhibition zone shows no variety when the concentration increases above 0.4%. None of the concentration above shows effect against pseudomonas aeruginosa.2. Appling different concentrations of as disinfector, compare the dimensional accuracy of the following three groups: mixture of bromogeramine with alginate impression, mixture of bromogeramine with dental stone and traditional impression material of glutaraldehyde. The results are shown below:â‘ there is no remarkable duplicate difference (P>0.05) between different concentrations of alginate impression material and comparison group;â‘¡there is no remarkable duplicate difference (P>0.05) between different concentrations of dental stone;â‘¢there is no remarkable duplicate difference (P>0.05) between different concentrations of alginate impression material and dental stone impression material;â‘£As for the immersing group, with immersing time increasing, mesiodistal and buccolingual width of single crown will gradually decrease while occlusogingival height will gradually increase. And there is no remarkable difference (P>0.05) between immersing group and comparison group within immersing time of 35min. However, for the immersing group of 45 min and 16h, there is remarkable duplicate difference (P<0.05) between comparison group and immersing group.Conclusion:1. The certain concentrations (0.05%,0.1%,0.2%,0.4%) of bromogeramine show antibacterial effect against usual dental bacteria besides the pseudomonas aeruginosa. Better antibacterial effect was shown by increasing concentrations till 0.4%.2. There is no remarkable difference of dimensional accuracy between two kinds of mixtures, which are made by mixing alginate impression and dental stone with certain concentrations (0.05%,0.1%,0.2%,0.4%) of bromogeramine. However, the deformation will increase with longer immersing in 2% glutaraldehyde There is statistics difference shown after 45minutes of immersing. It is not suitable for long time of immersing alginate.