Ceramic Collar

We have a double-bore ceramic tube. We break off 15 mm of it and run two fresh springs through the two bores. We coat the springs with silicone and move them in and out until the silicone penetrates all the way through the bore. We leave to cure. If silicone bonds well to ceramic, and ceramic bonds well to dental cement, we may have an effective insulating collar.

Our two springs are cemented securely in the ceramic tube by silicone. We tug with sufficient force to stretch the springs, but there is no yield in the bond between the ceramic and the steel. We put the ceramic tube in dental cement.


Figure: Two-Bore Ceramic Collar in Dental Cement.

We pull on the springs with pliers. They stretch all the way until nearly straight. The silicone bond within the ceramic tube remains intact. We pull harder and the steel tears out of the silicone. We grab the ceramic with pliers and try to break it out of the dental cement. We crack the ceramic, but the bond between the two materials does not break.