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Accuracy of wax, autopolymerized, and light-polymerized resin pattern materials
A Iglesias1, J M Powers, H P Pierpont
1University of Texas-Houston Health Science Center, Dental Branch, USA.
Summary
Light-polymerized diacrylate resins offer superior marginal fit for dental restorations compared to wax or autopolymerized acrylic resin. These materials demonstrate better accuracy and are less affected by fabrication technique and storage time.
Area of Science:
- Dental Materials Science
- Prosthodontics
- Biomaterials Engineering
Background:
- Accurate marginal fit of dental restorations is crucial for long-term success.
- Traditional pattern materials like inlay wax and autopolymerized acrylic resin have limitations in achieving optimal marginal integrity.
- Advancements in light-polymerized resins offer potential improvements in pattern fabrication for indirect restorations.
Purpose of the Study:
- To compare the marginal fit of MOD inlay and full-crown patterns.
- To evaluate four different pattern materials: inlay wax, autopolymerized acrylic resin, and two light-polymerized diacrylate resins.
- To assess the influence of fabrication technique (incremental vs. bulk) and time on marginal gap formation.
Main Methods:
- Four pattern materials were tested: Palavit G LC, Triad VLC Burnout Paste (light-polymerized diacrylate resins), inlay wax, and Duralay (autopolymerized acrylic resin).
- Patterns were fabricated using incremental and bulk techniques on standardized stone dies.
- Marginal gaps were measured using a measuring microscope at 1 and 24 hours post-fabrication.
Main Results:
- For MOD inlay patterns, light-polymerized resins and autopolymerized acrylic resin showed smaller marginal gaps than inlay wax.
- For full-crown patterns, light-polymerized resins and inlay wax had smaller gaps than autopolymerized acrylic resin, especially when using the incremental technique.
- Incremental technique generally yielded smaller marginal gaps than the bulk technique for full-crown patterns.
- Patterns fabricated at 1 hour typically exhibited smaller marginal gaps than those measured at 24 hours.
Conclusions:
- Light-polymerized diacrylate resins demonstrated equal or superior marginal fit compared to wax and autopolymerized acrylic resin.
- These resins were less susceptible to variations in placement technique and storage duration.
- All tested pattern materials produced marginal gaps within the clinically acceptable range (7-46 microns).