Parallelism of abutment teeth on fixed partial dentures.

A total of 100 working dies for fixed partial denture (FPD) abutments were prepared to fit 50 three-unit fixed-fixed conventional FPDs. For each FPD, the axial convergence angles between the mesial and distal axial walls of the abutment teeth were measured. For all FPDs, there were no statistically significant differences between the mesial and distal convergence angles of abutment teeth measured, regardless of their location within the oral cavity. The distal convergence angle of posterior FPD abutments was the highest angle, while the lowest was recorded for the mesial convergence angle of the anterior FPD abutments.