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Purpose: The purpose of this study was to determine the marginal discrepancy and
retention of silver-palladium crowns cemented with zinc phosphate (Phosphacap) and
glass-ionomer cement (Fuji Cap 1) using different seating forces on preparations with
various margin designs. Materials and Methods: Crown preparations with three finish
lines—chamfer, shoulder, and shoulder with a 45-degree bevel—were sequentially
prepared on a dentoform premolar. A metal die for each of the three finish lines was
constructed. Complete metal crowns were fabricated for each metal die using a silverpalladium
alloy. Three different seating forces—25, 100, and 300 N—were used to load
the crowns until initial set of the cement. The marginal discrepancy was calculated by
measuring the change in crown height before and after cementation using a digimatic
indicator. Retention was determined by measuring the tensile strength using the Lloyd
universal testing machine. Results: The higher seating forces produced better crown
seating but had no significant effect on crown retention. The shoulder and shoulder with
bevel finish lines provided better crown retention than the chamfer. Glass-ionomer
cement provided greater crown retention than zinc phosphate cement. No significant
correlation between marginal seating and crown retention was revealed using a Pearson
analysis. Conclusion: Marginal seal was not influenced by either margin design or type of
luting cement, but was improved with higher seating force. Crown retention was affected
by the margin finish line and the luting agent.
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