Effect of disunfection of acrylic resin custom trays on adhesive property of polyvinyl siloxane impression material adhesive systems

ABSTRACT

The bond strength for elastomeric materials to prevent detachment of the impression from the custom tray is important. The effect of disinfection procedure of custom trays with freshly prepared 1213 iodophor and 10% sodium hypochlorite disinfectants on the tensile bond strength of polyvinyl siloxane impression adhesive/ systems were evaluated. Thirty autopolymerizing resin plates were made in silicone mold. Before, the resin became rubbery, a metal nut with retentive threads was embedded so that an eye bolt could be thread into it for attachment during tensile testing. The specimens were stored in ambient air for 24 hours before testing. Ten specimens were exposed to freshly prepared 1213 iodophor and additional 10 resin specimens were exposed to freshly made 10% sodium hypochlorite disinfectant solution. The specimens were stored in sealed plastic bags for 24 hours. The remaining 10 specimens served as control. After application of adhesive, addition reaction silicone impression material was injected over the tray specimens. The force necessary to separate the impression from the tray material was recorded using Instron Universal Load Testing Machine. The results indicated that the use of iodophor and sodium hypochlorite disinfectant solutions reduced the bond strength of impression adhesive system to autopolymerizing resin tray compared to control [iodophor = .38 MPa, sodium hypochlorite= .49 MPa, control .52MPa]. It is therefore suggested to perforate the tray at the construction stage and disinfected in the laboratory to overcome the reduced bond strength of polyvinyl adhesive / system to tray material: