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

Area of Science:

• Dental materials science
• Prosthodontics
• Manufacturing technology

Background:

• Accurate fabrication of dental prosthetics relies on precise wax patterns.
• Traditional handmade techniques may introduce variability in wax pattern dimensions.
• Advancements in digital dentistry offer potential improvements in fabrication precision.

Purpose of the Study:

• To compare the dimensional precision of wax patterns created with Computer-Aided Design/Computer-Aided Manufacturing (CAD/CAM) versus traditional handmade methods.
• To evaluate key parameters influencing prosthetic accuracy, including thickness and cement gap.
• To determine if CAD/CAM technology offers superior accuracy for dental wax patterns.

Main Methods:

• Twelve wax patterns were fabricated: six by hand and six using CAD/CAM technology (3 Shape software) on a mandibular molar preparation.
• Nano-computed tomography (nano-CT) was employed for high-resolution scanning of all patterns.
• Key dimensional parameters including buccal thickness, occlusal thickness, and associated cement gaps were measured and statistically analyzed.

Main Results:

• CAD/CAM-fabricated wax patterns demonstrated statistically significant improvements in precision.
• Occlusal thickness was notably reduced in CAD/CAM patterns (26 ± 2 mm) compared to handmade (72 ± 5 mm, P < 0.01).
• Buccal thickness was more consistent with CAD/CAM (24 ± 3 mm) than handmade patterns (33 ± 4 mm, P < 0.01), while cement gaps remained comparable.

Conclusions:

• CAD/CAM technology significantly enhances the precision of wax pattern fabrication for dental prosthetics.
• This digital approach reduces dimensional variability compared to traditional handmade techniques.
• CAD/CAM ensures maintained fit quality while improving overall fabrication accuracy.