Method: One poly vinyl ether silicone, one polyether, and 8 polyvinyl siloxane IPs were examined. For water CA on IP, a flat slab was made of the light body version of each of these materials. A calibrated drop of water was dropped on the slab and a video recording and CA measurement at 1s intervals was made with a goniometer. For IP on tooth, bovine enamel and dentin was flattened to 600 grit and maintained wet. Then the surface was wiped immediately before dropping the drop of IP. A calibrated drop of IP was placed on the tooth surface through a mixing tip and fine delivery tip. The CA was recorded as previously described. Data were analyzed at 5s, 30s and 60s after the drop was created. 3Way ANOVA was run.
Result: CAs decreased over the time of measurement. CAs were similar on enamel and dentin for each material. By 60s the CA of water on the set material was lower than that of IP on tooth. 30s CA of IP on tooth ranged 55o-100o, and water on IP 21o-115o.
Conclusion: No one material was uniquely better set or unset. This method can record an adaptation “contact angle” immediately after mixing.
Keywords: Contact angle, Dental materials and Impression materials
See more of: Dental Materials 7: Polymer-based Materials-Physical Properties and Performance