Color-Stable Formulations for 3D-Photoprintable Dental Materials

Area of Science:

• Dental Materials Science
• Additive Manufacturing
• Polymer Chemistry

Background:

• Color stability is critical for dental restorative materials to achieve accurate shade matching.
• Discoloration in photoresist-based additive manufacturing presents a significant challenge for aesthetic dental applications.
• The precise causes of discoloration and effective mitigation strategies in 3D printing dental resins require further elucidation.

Purpose of the Study:

• To investigate the intrinsic causes of discoloration in materials intended for 3D printing dental applications.
• To evaluate the influence of material composition and storage conditions on discoloration.
• To develop and validate methods for minimizing or preventing discoloration in dental 3D printing resins.

Main Methods:

• Thin-film samples (1200 µm) of various compositions were prepared.
• Samples were stored under controlled, differing environmental conditions.
• UV-Vis absorption spectra were measured at regular intervals to quantify color changes.

Main Results:

• Both the formulation composition and storage conditions significantly affect the discoloration of dental 3D printing materials.
• The use of photoinitiators with sterically hindered benzoyl groups and the addition of stabilizers reduced discoloration intensity.
• Incorporating cumene hydroperoxide (CHP) as an oxidizing agent led to materials exhibiting excellent color stability.

Conclusions:

• Material composition and storage environment are key factors governing color stability in dental 3D printing resins.
• Strategic selection of photoinitiators and inclusion of stabilizers can mitigate discoloration.
• The addition of cumene hydroperoxide offers a promising approach for achieving long-term color stability in dental additive manufacturing materials.