Effects of Sintering Shrinkage on the Marginal and Internal Fit of
CAD/CAM-fabricated Zirconia Frameworks
9 Unit Bridge (#6 - 14)
Messial & Lingual Margin Open on #13
Problem
Even thickness of continuous copings (#12 & 11) produced good fitting. Five unit bridge (#6 & 10) with small pontic (P3) produced good fitting too. But entire bridge with large pontic area (P1 & P2) failed to seat positive with mesial sides (A & B) open and distal sides (C & D) tight.
Reason
Marginal gaps on the pontic side were significantly larger than those on the non-pontic side. When the distance between abutments become larger the discrepancy between the pontic and non-pontic sides also become larger.
