Aim: This study used a photoelastic analysis to evaluate the passive
fit of titanium cast laser welding frameworks before and after spark
erosion procedure. Methods: A stainless steel cast was used in order to
reproduce a human mandible. Five Multi-Unit abutment analogs were
attached to this cast and 6 frameworks were produced in commercial pure
titanium. The cast was molded and a photoelastic matrix was produced
incorporating 5 dental implants with Multi-Unit abutments. All samples
were subjected to a laser welding. The precision of adjustments within
a range of 0.5 μm was evaluated under microscope observation. The
best fitted framework was selected and subjected to a photoelastic
analysis (Group I). The tightening of the screws was in 3 predetermined
sequences (1,2,3,4,5/ 5,4,3,2,1/ 3,2,4,1,5). Then the same framework
was subjected to a refinement by spark erosion technique (Group II) and
evaluated by photoelastic analysis. Results: The sequence (3,2,4,1,5)
achieved better results in both groups. A larger number of fringes were
observed around the median implants in all sequences in both groups.
Conclusions : The titanium cast laser welded frameworks processes
associated with spark erosion procedure improves significantly the
marginal framework adaptation and is effective for its passive fit
