A Feasible and Innovative Method of Investing Wax Pattern for Removable Partial Dentures: An In Vitro Study

Area of Science:

• Dentistry
• Materials Science
• Biomedical Engineering

Background:

• Removable partial dentures (RPDs) are crucial dental prostheses for replacing missing teeth.
• RPDs offer an alternative to fixed bridges and implant-supported restorations.
• Current RPD fabrication involves traditional investment casting methods.

Purpose of the Study:

• To introduce a simple, effective, and cost-efficient method for investing RPD wax patterns.
• To investigate the precision of a novel RPD fabrication technique using a paper ring.
• To compare the novel method with traditional ringless investment casting.

Main Methods:

• A novel technique using a laminated paper ring for investing RPD wax patterns was developed.
• The precision of the cast framework was validated through in vitro investigation.
• A comparison was made between the novel method and traditional investment casting using 30 samples (15 per group).

Main Results:

• The innovative wax pattern investment method showed a statistically significant higher mean geometric orientation (9.23 ± 0.42 mm) compared to traditional casting (8.90 ± 0.37 mm).
• The novel method also demonstrated a statistically significant lower mean dimensional accuracy (0.28 ± 0.03 mm) than traditional casting (0.31 ± 0.05 mm).
• The study achieved high statistical power (0.999) for both parameters, indicating reliable results.

Conclusions:

• The innovative paper ring method eliminates the need for commercial plastic rings, reducing RPD manufacturing costs and time.
• This technique provides acceptable marginal accuracy for RPDs.
• Challenges in preparing the paper ring post-investment may impact final prosthesis quality, requiring further refinement.