Background: Wax patterns are fabricated with wax using particular waxing instruments in conventional techniques. The present study was conducted to compare marginal and internal fit of metal copings cast from wax patterns fabricated by CAD/CAM and conventional wax up techniques.

Materials & Methods: 30 standardized brass dies were randomly divided into 2 groups according to the wax-patterns fabrication method. Group I comprised CAD/CAM technique and group II conventional method. Each group comprised of 15 dies.

Results: Marginal gap in group I was 145.2 µm and in group II was 72.6 µm, absolute marginal discrepancy in group I was 215.7 µm and in group II was 90.4 µm, internal gap axial in group I was 82.4 µm and in group II was 61.2 µm, internal gap occlusal in group I was 192.4 µm and in group II was 120.5 µm and internal gap total in group I was 112.6 µm in group II was 74.2 µm. The difference between both groups was significant (P< 0.05).

Conclusion: Conventional method of wax-pattern fabrication produced copings with significantly better marginal and internal fit than CAD/CAM (machine-milled) technique.