The purpose of this study is twofold. One is to evaluate the wettability of 4 elastomeric impression materials on tooth and different kinds of filling materials. The other is to identify the effect of topical surfactants sprayed on the surface of each impression. The elastomeric impression materials used in this experimental study were one polyether(Impregum F) and three polyvinyl siloxanes(Provil novo, Zerosil, Imprint). The abutments were prepared for 3/4 crown or onlay on the extracted human first molar. The filling materials used in this study for the duplication of prepared abutment were composite resin, amalgam, and casting metal. Impression was taken by manufacturer´s recommendations and the number of voids on the impression surface was counted. The topical surfactants were Spannex I " and Cohere. The wettability was evaluated by comparing the number of voids between non-treated group and treated groups.
The 1. sults were as follows:
1. Zerosil* showed the least number of voids on the impression surface. The number of voids increased in order of Provil novo, Impregurn F, and Imprint´.
2. Impregum F and Zerosil´ showed the least number of voids on the surface of dental stone master cast. The number is incresed in order of Provil novo and Imprint.
3. When abutment material is tooth, the number of voids on the surface of master cast was smallest compared with that of other abutment materials. The number of voids increased in order of casting metal, amalgam and composite resin.
4. The number of voids on the surface of the dental stone master cast was smallest when Spannex I was used, followed by Cohere treated group and non-treated group.
These results suggest that the difference in wettability caused by the types of rubber base impression materials as well as abutment materials can affect the number of voids. And the use of topical surfactant for rubber base impression materials can improve the wettability of the materials and enhance the accurate master cast which has fewer surface voids.
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