Effects Of Adding Nano-silver Base Inorganic Antibacterial Agent And Denture Cleaners On Antibacterial And Mechanical Property Of Room Curing Polymethylmethacrylate Material

As a linking science between the Stomatology and Materialogy,Scie-nce of Dental Materials has developed rapidly in recent years.Newmaterials and new technology come out and develop new directions ofStomatology. Roomtemperature curing polymethylmethacrylate (PMMA)is a kind of dental restoration,it’s mainly used in rebasing of completedenturere,orthodontic appliance,Maxillofacial guide,etc.It is not onlyconvenient and efficient but also nontoxic and nonirritating, in addition,itis very cheap.the nano silver has been proved that it exhibits antibacterialproperty to a variety of pathogenic microorganisms in oral cavity.Ourpreliminary research found that adding2%Nano-silver base inorganicantibacterial agent in room temperature curing PMMA can improve theantimicrobial properties of materials.To be a kind of effective method of cleaning denture, it must exhibitgood antibacterial property. Candida albicans is the major pathogenicbacteria to lead denture stomatitis.The specific properties of PMMAlike porosity,irregularity and water absorption,as well as theincreasing of surface roughness caused by long time using,promotedeposition of pathogenic bacteria on its surface. Therefore,toremove candida albicans plays an important role in prevention andtreatment of denture stomatitis.Bending strength is one of mainmechanical properties of denture base, an effective antibacterial methodshould not only have good antibacterial effects, but also keep the bendingstrength of denture base well. In choosing method to clean denture, most of the patients tend to usemechanical brushing,a few patients have used denture cleansers.Thefollowing methods were used to against C.albicans on room curingPMMA:1)2%Nano-silver base inorganic antibacterial agent was added;2)immersed in4frequently-used denture cleaners(Polident,Y-Kelin,Victoria-C,Protefix);3)Mechanical brushing.Antibacterial rates of thespecimes were detected by film method.According to the process modeabove,the specimes underwent accelerated aging process for14days inthe imitated oral environment.Bending strength were detected onelectronic universal testing machine.The main experimental results are as follows:1.Mechanical brushing could make Candida albicans reduce, butthe bending strength of room curing PMMA would be influenced bybrushing for a long time.2.Using denture cleaners also have antibacterial effect.Polidentexhibited the best antibacterial property in four cleansers，the antibacterialproperties of three others were so and so, the combination ofmechanical and chemical methods seemed to be the better choice fordenture cleaning. The bending strength of four cleansers did not have thesignificance change.3.The antibacterial rate to C.albicans of all methods was different,itinfluenced by many infactors,such as individual difference and themethod people used was accurate or not.4.The method of adding2%Nano-silver base inorganicantibacterial agent exhibited the best antibacterial property.And thebending strength of nano-silver base room curing PMMA kept well.this method was more convenient and would be used more widelyand have wonderful further.