Effect of Expiration Date on Flexural Strength of 3D-Printed Interim Resin Material

Natalia Jakacki, BS; Tyler McCluskey; Ramtin Sadid-Zadeh, DDS, MS; Chin-Chun Peng, DDS, MSD; Rui LI, DDS, PhD

The aim of this study was to evaluate the effect of expiration date and thermocycling on flexural strength of 3D-printed interim resin material. 

In the rapidly evolving field of 3D-printing, the quality and durability of printed materials play an essential role in their clinical applications. The use of 3D-printed interim resin restorations are increasing due to the expansion of intraoral scanners, simple dental computer-aided design (CAD) software, and improved 3D-printing speeds. Interim restorations have many functions ranging from the protection and healing of periodontal tissue to the testing of esthetics or occlusal schemes. These types of restorations usually have a limited life span in prosthetic therapy, however; certain situations can be associated with long-term use. It is important to understand how proper handling techniques of 3D-printed materials can have an effect on their mechanical properties. The effect of expiration date on the flexural strength of 3D-printed resin is an important factor to consider. It is common for dentists to  have unused expired 3D-printable resin material in their office. Should this material be discarded or can it be used past the expiration date? This study evaluated the effect of expiration date on flexural strength of 3D-printed interim resin material. Half of the tested specimens were thermocycled in order to simulate the aging process of the material.