Tensile Bond Strength Between The Tray Material And Impression Material: An In Vitro Study

OBJECTIVE To compare the tensile bond strength after different trays were bonded with additional silicone material or alginate impression material and the time-dependent bond strength of two tray material to an additional silicone. To find the optimal way and time for the maximum bond strength.METHODS ?the self-cured acrylic tray was fabricated. The samples were divided into four groups: non-adhesive group: Adhesive group, perforation group, adding mesh group. The bond strength was measured in a universal testing machine.? with the same kind of acrylic tray. The samples were divided into six groups: non-adhesive group, adhesive group, saliva-contaminated group, perforation group, roughened surface group, perforation adding adhesive group. The bond strength was measured(Dthe A-adhesive was applied to surface of the light-cured tray and self-cured acrylic tray and was allowed to dry for 1,3,7,15,30,60 minutes and 16 hours. The changes of bond strength were observed.RESELTS (2)Significant difference of tensile bond strength was found among four groups (P<0.01) ; Multiple Comparison showed significant difference between four Groups respectively (p<0.01).(2)significant difference of bond strength was found among six groups. ( P<0.01) there are no significant difference between adhesive group and perforation group. ( P>0.05 ) significant difference was found between adhesive group and other groups. (.P<0.05 ) (3) the type of tray material, adhesive drying time, and their interaction demonstrated significant effects on tensile bond strength. CONCLUSIONS (1)adding mesh in custom tray is a new way to increase the bond strength effectively. (2) the saliva contamination can reduce tensile bond strength significantly, but roughened surface can increase it. (3) There is the highest bond strength in 15min group.