Preliminary Study Of Effect Of Fungal Growth On Silicone Elastomer Containing Antifungal Agents

Silicone elastomer is the regular material in maxillofacial prosthetics,. Maxillofacial prosthesis and obturator usually are made by silicone elastomer.SY-1 two-component room temperature vulcanizing silicone elastomer (RTV'S) is a new type of maxillofacial prosthetic elastomer developed in the Fourth Military Medical University. In order to resolve aging problem induced by Candida albicans (during the wearing period of time of silicone elastomer) and to prolong its clinical time, antifungal agents were added into silicone elastomer materirals.The antimicrobial effect of the silicone elastmer was examined in this study. First,antifungal agents were added into Silicone elastomer materials respectively by the ratio of 0.5,1,1.5,2 W/W agent/material , then the antimicrobial effect of the silicone elastmer was examined by in vitro bacteria culture and the most probable number counting.Secondly,antifungal agents were added at concentrations from 0% to 2%,and subsequently,antibacterial effect of the material in the control ,saliva and serum group were examined through monitoring the pH of the growth medium.Effects of Candida albicans on silicon elastomer with antifungal agents were examined. Finally, the mechanical properties changes of silicone elastomer impregnated with Conval pag-40 and AntimTM-AM were compared.The following outcomes have been determined.1. The pieces with two different antifungal agents showed significantly anti-fungal ability.There were significant differences among the antifungal effect of the two agents.Conval pag - 40 containing 1.5% showed a significantly greater antifungal effect than AntimTM-AM.The antibacterial ratios of silicone elastomer impregnated with Conval pag-40 with 2% was beyond 80%.2. Each group of antifungal agents showed an inhibitory effect on the acid production and /or the growth of C.albicans.These inhibitory effects consisted of a delay in the onset of rapid pH decline, a decrease in the rate of pH change as well as an increase in minimum pH.There were significant differences among the antifungal effect of the two agents with 1.5% and 2%. Conval pag-40 showed a significantly greater antifungal effect than AntimTM-AM.3. In the primarily study, the effect of antifungal agents to mechanical properties of SY-1 silicone elastomer, tensile strength(MPa), elongation at break (%),tear strength(kN/m), permanent deformation rate(3 minutes)and Shore-A hardness were investigated.With the increase of the antifungal agents, the Shore A hardness and permanent deformation increased,the tensile strength,the elongation at break and the tear strength decreased.