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Optimizing Photoinitiator Concentration in 3D-Printed Resins for Provisional Dental Restorations
Emanuela Gaviolli1, Fabricio Mezzomo Collares1, Gabriela de Souza Balbinot1
1Dental Materials Laboratory, School of Dentistry, Federal University of Rio Grande do Sul, Porto Alegre, RS, Brazil.
Brazilian Dental Journal
|November 26, 2025
Summary
This study found that 3% TPO in 3D-printed dental resins improved mechanical properties and conversion but caused color changes. The 1% TPO resin, post-cured for 30 minutes, showed balanced results for provisional restorations.
Area of Science:
- Biomaterials Science
- Dental Materials Science
- Polymer Chemistry
Background:
- 3D-printed resins are increasingly used for provisional dental restorations.
- Optimizing photoinitiator concentration is crucial for resin performance.
Purpose of the Study:
- To evaluate the impact of varying TPO photoinitiator concentrations on the mechanical, physicochemical, and biological properties of 3D-printed resins.
- To determine the optimal TPO concentration for 3D-printed provisional dental restorative materials.
Main Methods:
- Resin formulations with 1%, 2%, and 3% TPO were prepared using UDMA, TEGDMA, BHT, and BaSil.
- Specimens were 3D printed using SLA/LCD technology and post-processed via ultrasonication and UV curing (10 or 30 min).
- Evaluated properties included degree of conversion, flexural strength/modulus, Knoop microhardness, solvent softening, color stability, and cytotoxicity.
Main Results:
- Higher TPO concentration (3%) significantly improved flexural strength and modulus, with 10 min post-curing.
- Degree of conversion showed no significant difference between 1% and 3% TPO groups.
- All groups experienced hardness reduction after solvent exposure; post-curing time affected hardness in the 1% TPO group.
- Cytotoxicity was not significantly different across groups.
- 1% TPO with 30 min post-curing exhibited clinically acceptable color stability, while 3% TPO showed significant color change after aging.
Conclusions:
- 3% TPO concentration enhances mechanical properties and degree of conversion in 3D-printed resins but leads to significant color instability.
- 1% TPO concentration with 30 minutes of post-curing offers a promising balance of mechanical properties, acceptable color stability, and low cytotoxicity for provisional dental restorations.
