Strong, impact resistant rubberized-urethane doesn't shrink or distort and grips the tooth tightly. Virtually eliminates fractures and debonding. Grinds and powders during trimming without softening or distorting. Tough and resilient, it is impact and fracture resistant. It greatly reduces breakage and cementation failures and grinds without softening or gumming up. Its self-cure with fast light cure option.