Study On The Influence Of Nano-Ag/TiO₂Base Inorganic Antibacterial Agents On Antibacterial And Mechanical Property Of Room Curing Polymethylmethacrylate Material

Polymethyl methacrylate material is an important member of dentalProsthodontics materials,according to the curing method dividing into theheating-curing, room-curing,and photo-curing three types.The room-curing PMMAmaterials used very widely because simple operation,excellent physical and chemicalproperties,and excellent biocompatibility.When it applied to relining of completedenture and removable partial denture,appliance activities,cementing parts ofprecision attachment, also require materials in the oral environment for a longtime,leading to flora easily, cause caries and dental stomatitis finally,in order toprevent above diseases thereby antibacterial problem has become the key point.Nano-Ag/TiO₂base inorganic antibacterial agent is a new type of compositenano inorganic antibacterial agent,by combing TiO₂photocatalytic and Ag+antibacterial effect,with or without UV all have antibacterial activity,but with UVantibacterial activity enhancement.So far has not been reported research thatnano-Ag/TiO₂base inorganic antibacterial agent join into room-curing PMMAmaterials endowed it antibacterial properties,so join the antibacterial agent into theroom-curing PMMA material in order to give it antibacterial activity and does noteffect the mechanical properties, so as to provide theoretical basis for joining intoroom-curing PMMA material.This experiment using ball milling method,mixing nano antibacterial agent androom-curing PMMA powder effectively,Candida albicans and Streptococcus mutansas antibacterial testing selected bacteria.First detection of nano-Ag/TiO₂baseinorganic minimum bactericidal by broth dilution method,then according to itdetermination of specimen with different concentration,then detection of antibacterialrate by film method and adhesion of different concentrations of antibacterial agents.Finally detection of bending strength,impact strength and elastic modulus ofdifferent concentration,comparing and analysising the effect of mechanical propertiesof room-curing PMMA with nano-Ag/TiO₂base inorganic antibacterial agent.This experiment concluded that contenting different concentration of nano–Ag/TiO₂base inorganic antibacterial agent showed certain antibacterial in vitro teston Candida albicans and Streptococcus mutans,and enhancement the antibacterial ratein the UV conditions. In the UV conditions when the content of antibacterial agent ismore than1%in the room-curing,has a bactericidal effect against Candidaalbicans;and when the content of antibacterial agent is more than1.5%in theroom-curing,has a bactericidal effect against Streptococcus mutans.But has no effectto adhesion of two types bacteria on the surface of different concentrations ofantibacterial agents.When the content of antibacterial agent is more than2%in theroom-curing,the mechanical properties of sample contenting different concentrationswill be declined.So with the UV conditions to reduce the effect of the mechanicalproperties of room-curing PMMA materials join into nano–Ag/TiO₂base inorganicantibacterial agent.In all,nano-Ag/TiO₂base inorganic antibacterial agent join intoroom-curing PMMA materials to prevent caries and dental stomatitis is effect.