Comparison of the Polishability of 3D Printed Denture Base Materials

Objectives: The surface characteristics of removable dental prostheses are critical in biofilm accumulation and cleansability. Surface roughness can increase the retention of pathogenic microorganisms and decrease surface cleansability, thus emphasizing the importance of surface smoothness. This research aims to determine if 3D printed denture materials, using different additive manufacturing techniques, can achieve the same level of polishability as conventionally created resin denture materials.
Methods: To obtain a clinically predictable method of polishing for 3D printed denture materials, three different 3D printing technologies, along with conventional lab fabricated PMMA auto cured resin, were utilized to create ten cylindrical samples in which five of each type were polished using the Pala Polishing one-step system or the Miltex course and fine pumice with Acryluster polishing system. The printing technologies used for manufacturing the samples include Stereolithography (SLS), Digital Light Processing (DLP), and Continuous Liquid Interface Printing (CLIP) using the Formlabs USA Form3B, SprintRay Pro Desktop Dental 3D printer, and Carbon M2d printer. Each 3D printer used denture base resin from the same manufacture (DENTCA) and the samples printed were identically sized cylinders. After polishing, the surface roughness and surface gloss of each sample were measured and analyzed.
Results: Preliminary data suggests that 3D printed denture materials can achieve a higher level of polishability when compared to conventionally fabricated resin denture materials when polished with the Pala Polish Cream system versus the conventional pumice system.
Conclusions: Due to the scarcity of research on the polishability of 3D printed materials despite the growing trend and convenience of digitally manufactured products, this research’s intent is to provide and equip the dental community with polishing protocols. It is paramount that as dentistry and materials advance, so do the polishing techniques, ultimately refining and enhancing patient care.