[Physical properties of resins for veneer crown. (Part 2) Bending strength and retention force of opaque resins (author's transl)].

The retention force of 9 kinds of resins for veneer crown, physical properties and retention force of 7 kinds of opaque resins were determined. Retention force and their physical properties were closely related on resins for veneer crown, that is stronger and more tough resins have larger retention force. The opaque resins containing larger quantity of filler and hydrophilic monomers showed extra-ordinary young's modulus afteter drying. But young's modulus and strength decreased after immersed in water and thermal cycling and the retention force also decreased to the smallest level after immersed in water and thermal cycling. The hydrohobic opaque resins that have good coupling effect to filler showed large retention force even after immersed in water and thermal cycling in spite of large filler content. The opaque resins containing MMA with scanty filler showed large elongation and breaking strength and their retention force were also large after immersed in water and thermal cycling.