Comparing 3D-Milled Wax Patterns to Hand Crafted Wax Patterns - An In-vitro Study

This study aimed to evaluate and compare the precision of wax patterns fabricated using traditional handmade techniques versus advanced Computer-Aided Design/Computer-Aided Manufacturing (CAD/CAM) technology, focusing on key dimensional parameters relevant to prosthetic accuracy.

A total of 12 wax patterns were prepared, with six using traditional handmade methods and six using CAD/CAM technology using 3 Shape software on an extracted mandibular molar crown preparation. The nano-CT was used for the scanning the samples. The patterns were assessed for buccal thickness, buccal cement gap, occlusal thickness, occlusal cement gap, functional cusp thickness, and functional cusp cement gap using high-resolution imaging techniques. Data normality was tested and was statistically analysed.

CAD/CAM-fabricated wax patterns exhibited statistically significant improvements in precision for several key parameters. Specifically, the mean occlusal thickness of CAD/CAM patterns (26 ± 2 mm) was notably reduced compared to handmade patterns (72 ± 5 mm, P < 0.01). Additionally, CAD/CAM patterns demonstrated a more consistent buccal thickness (24 ± 3 mm) compared to handmade patterns (33 ± 4 mm, P < 0.01). Cement gap measurements were comparable between both methods, indicating that fit quality is maintained across fabrication techniques.

The study demonstrated that CAD/CAM technology offers superior precision in wax pattern fabrication compared to traditional methods, with significant reductions in dimensional variability.