Marginal Adaptation of Provisional CAD/CAM Restorations Fabricated Using Various Simulated Digital Cement Space...

Area of Science:

• Dental Materials Science
• Biomaterials Engineering
• Digital Dentistry

Background:

• Accurate marginal adaptation is crucial for the longevity and clinical success of provisional dental restorations.
• Computer-aided design/computer-aided manufacturing (CAD/CAM) offers precise fabrication of dental prosthetics.
• The optimal digital cement space for provisional CAD/CAM restorations remains under investigation.

Purpose of the Study:

• To evaluate the impact of varying simulated digital cement space settings on the marginal fit of provisional poly(methyl methacrylate) (PMMA) restorations fabricated using CAD/CAM.
• To determine the ideal cement space for achieving clinically acceptable marginal adaptation in provisional CAD/CAM crowns.

Main Methods:

• Extracted premolar teeth were prepared and scanned to create digital models.
• CAD software was used to design PMMA crown cores with three distinct cement space settings: 20-40 μm, 20-50 μm, and 20-60 μm.
• Marginal gap measurements (vertical marginal discrepancy) were performed using a stereo zoom microscope and analyzed with ANOVA.

Main Results:

• Significant differences in marginal gap values were observed across all three cement space settings (P < .001).
• The 20- to 60-μm cement space setting resulted in the smallest marginal gaps.
• Increasing the cement space generally led to a reduction in the marginal gap size.

Conclusions:

• Larger digital cement space values correlate with smaller marginal gaps in CAD/CAM-fabricated PMMA provisional restorations.
• A cement space setting of 20 to 60 μm demonstrated the most favorable marginal fit.
• These findings provide valuable data for optimizing the digital design of provisional CAD/CAM restorations.