The accuracy comparison of 3D-printed post and core using castable resin and castable wax resin.

PURPOSE: The purpose of this research was to compare the accuracy of three-dimensionally (3D) printed post and core fabricated with two different materials: reinforced wax and castable resin. MATERIALS AND METHODS: Fifteen extracted single root central incisors were selected. Root canal treatment and tooth preparation for crown were performed on all teeth. Eleven millimeters post space was created with standardized prefabricated fiber post drill. Polyvinylsiloxane impression material was used for root canal impressions. Each impression was then 3D scanned using an extraoral scanner and cast posts and cores were designed using 3Shape software. The digitally designed post and cores were 3D printed with two different materials: castable wax resin and castable resin. The castable resin patterns were scanned before and after complete polymerization. The wax patterns were also scanned. Digital volumetric measurement using Geomagic® Control X™ software was performed to determine accuracy.

RESULTS: The printed post and core had reduced volume (16.09 ± 3.839 mm3 ) compared to the digital design (17.828 ± 3.904, p < 0.05). Before complete polymerization, the accuracy of 3D printed resin pattern (16.464 ± 3.017) was found to be superior to post and core printed with wax (16.193 ± 3.018, p < 0.05). However, no volume difference was found between completely polymerized resin (16.09 ± 3.839) and wax (16.044 ± 3.834, p = 1).

CONCLUSION: 3D printed post and core showed significant volume shrinkage from the digital files used to create them. However, different materials had no effect on the accuracy of 3D printed post and core.