Retentive properties and film thickness of 18 luting agents and systems.

: In the past, retention of castings depended on mechanical interlocking or adhesion to enamel and dentin by means of chelation in the case of some cements. Some new luting agents adhere to metal and tooth structure. The era of bonded casts for crowns and bridges has arrived through a combination of dentin primers and luting agents that bond to enamel, dentin, and precious and nonprecious metals. For a few systems, the retentive forces (in an otherwise nonretentive experimental design) more often than not exceeded tooth strength.