This study was performed to investigate the effect of vent on the marginal discrepancy of PFM base metal castings. Eighteen identical wax patterns of a maxillary 3 unit anterior bridge were fabricated. Nine cases out of them were vented with $\phi$2.5...
This study was performed to investigate the effect of vent on the marginal discrepancy of PFM base metal castings. Eighteen identical wax patterns of a maxillary 3 unit anterior bridge were fabricated. Nine cases out of them were vented with $\phi$2.5mm sprue wax, for direct comparison as to the marginal discrepancy of the castings with the other non vented 9 ones. The mean value of marginal discrepancies of the vented castings was $85.02{\pm}25.57{\mu}m$, and that of the non vented was $163.21{\pm}69.88{\mu}m$ respectively. Statistical analysis revealed that marginal discrepancy of the vented casting was significantly reduced(p<0.05).