| The increasing awareness of infectious diseases and the recognition of transmission of infectious microorganisms during dental procedures, Patients and medical workers are taking more and more attention to the infection control and prevention in the whole process of diagnosis and treatment. Especially in recent years, serious infectious diseases such as HIV/AIDS, avian flu spread widely, and has resulted in a continuing effort to identify and eliminate possible routes for transmission and cross-contamination of diseases such as hepatitis B, tuberculosis, herpes, and AIDS. In the process of dental restorations, dental impression contacted with the patient’s saliva and blood, could become a medium for the spread of disease. Thus people take more attention to disinfection of dental impression material problem, However, there is not a set of perfect dental impression material in the oral cavity boundary of disinfection solution at home and abroad. Most scholars of dental impression before disinfection method has carried on the thorough research, there are the current clinical use of method is also more, such as: soaking disinfection method, spray disinfection method, directly adding disinfectant harmonic method and ultraviolet disinfection and so on. Immerses disinfection has been recognized by most researchers, because it is a method that bacteria contact with the surface of the stamping die, by adjusting the concentration of the disinfectant and the time, the spread of microbes could be effectively controlled. Therefore, this study aimed at evaluating a kind of new stable chlorine dioxide disinfectant, by observing the impression of bacteria microbial resistance and dimensional stability of impression materials after immersion disinfection, provide reference for clinical application. Objective 1. To evaluate the efficacy of chlorine dioxide on reducing the staphylococcus aureus and streptococcus sanguis which are adhesive on in the alginate impression material surface. 2. To evaluate the efficacy of chlorine dioxide on reducing the staphylococcus aureus and streptococcuss anguis which are adhesive on the silicone rubber impression material surface. 3. To evaluate the effect on impression material dimension stability after immersing disinfection. Methods 1. Putting the same specifications of impression samples into the concentration of 108 cfu/ml of staphylococcus aureus bacteria suspension streptococcus sanguis bacteria suspension, preparing impression material samples adhering bacterium. Bacterium impression specimens were randomly divided into three groups, respectively soaked in 2% glutaric dialdehyde, chlorine dioxide disinfectant and distilled water(control group), after10 minutes they were taken them out and put in neutralizer for 10 minuts, impression specimen are soaked in the phosphate bufferoscillating 20 seconds, 10ml of liquid with a eppendoff were injected on the surface of plate, bacteria liquid evenly coated on the plat surface with a sterile pushrod. 2. Two types of same specifications of impression samples randomly are divided into three groups, soaked in 2% glutaric dialdehyde, chlorine dioxide disinfectant respectively for 10 min, 20 min and 30 min, another group is the blank control group. And then samples are measured under electronic microscope, evaluate the influence of dimensional stability after impression materials are immersed into disinfectant. Results 1. Antibacterial rate of 2% glutaraldehyde to staphylococcus aureus on alginate surface is 99.32±0.80,antibacterial rate of the chlorine dioxide disinfectant group to staphylococcus aureus on alginate surface is 98.64±0.84, there was no statistically significant difference(P>0.05).Antibacterial rate of 2% glutaraldehyde to staphylococcus aureus on silicone rubber surface is 100.00±0.00,antibacterial rate of the chlorine dioxide disinfectant group to staphylococcus aureus on silicone rubber surface is 99.86±0.33, there was no statistically significant difference(P>0.05). 2. Antibacterial rate of 2% glutaraldehyde to streptococcus sanguis on alginate surface is 99.18±0.72, antibacterial rate of the chlorine dioxide disinfectant group to streptococcus sanguis on alginate surface is 97.96±0.85, there was no statistically significant difference(P>0.05).Antibacterial rate of 2% glutaraldehyde to streptococcus sanguis on silicone rubber surface is 99.45±0.66,antibacterial rate of the chlorine dioxide disinfectant group to streptococcus sanguis on silicone rubber surface is 98.91±0.67, there was no statistically significant difference(P>0.05). 3. Its shape of alginate impression after a 10-minute and a 20-minute treatment by 2% glutaraldehyde immersion disinfection was not statistically significant compared with control group(P>0.05), but its shape after soaking 30 minute was statistically significant, compared with control group(P<0.05). 4. Two kinds of impression material soaked in chlorine dioxide disinfectant different time, did not cause obvious impression material size change, after statistical analysis, the results was no statistical differences(P>0.05). 5. Two kinds of impression material soaked in 2% glutaraldehyde and chlorine dioxide, there was no statistical differences at the same time(P>0.05). Conclusion 1. chlorine dioxide disinfectant have good antibacterial effect for the alginate and silicone rubber impression materials with staphylococcus aureus and streptococcus sanguis. 2. Two kinds of disinfectants could not influence the dimensional stability of alginate impression, while the immersing time was the reason for the dimension change. Two kinds of disinfectants and the immersing time both could not influence the dimensional stability of silicone rubber impression material. 3. 2% glutaraldehyde immersion disinfection to alginate impression material within 20 minutes does not affect its dimensional stability, chlorine dioxide disinfectant in 30 minutes did not affect the stability of the size of alginate; Two kinds of disinfectant immerses disinfection do not affect the dimensional stability of silicone rubber impression material. |
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