Impression trays are often checked intraorally and border molded before the impression procedure. Contamination by saliva, as a result, is likely to affect the ability of tray surface to retain the impression material.
The purpose of this study is to investigate and compare the bonding strength of polysulfide adhesive to tray resin and border molding materials and, to evaluate the effects of saliva contamination on each.
The 135 resin tray specimens were made with dimensions of 1×1×1㎝ and were divided them into 3 groups according to their materials (Q, C, and I group)
Each group was subdivided according to saliva contamination.
Groups Q1, Q2, Q3 : applied adhesive without saliva contamination.
Groups C1, C2, C3 : applied adhesive after drying for 15 seconds after saliva contamination
Groups I1, I2, I3 : applied adhesive without drying after saliva contaminationn.
Tensile tests were performed with a Universal Testing Machine.
Results are as follows;
In the noncontaminated subgroup, there was no significant difference in bonding strength each of three groups.
In the tray resin group, the bonding strength, according to the degree of saliva contamination, significantly decreased in the following order: Q1, Q2, and Q3 group.
The C1, C2 and I1, I2 groups showed a significantly higher bonding strength as compared with the C3, I3 groups.
Impression compound and Impregum F showed the same high degree of bonding to polysulfide impression materials as did the Quicky resin material.
The above results suggest that saliva contaminated custom trays should be properly rinsed and air dried before tray adhesive is applied.
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