All ETDs from UAB

Advisory Committee Chair

Daniel A Givan

Advisory Committee Members

Daniel A Givan

Chin-Chuan Fu

Amjad Javed

Nathaniel C Lawson

Wenchou Wu

Document Type

Thesis

Date of Award

2023

Abstract

Digitalization of the design and manufacturing of complete dentures streamlines the clinical and laboratory processes and provides increased efficiency and enhanced denture quality.[1, 2] The two most common CAD/CAM techniques for denture base manufacturing are additive (3D-printing) and subtractive (milling) manufacturing. Milled denture bases have been proven to be comparable in their physical and mechanical properties to conventional heat-polymerized denture bases,[3-6] and in many studies found to be superior to 3D-printed denture bases.[7-13] However, 3D-printing offers many advantages over milling that appeal to both clinicians and dental technicians related to investment and operational costs, maintenance, speed of manufacturing, diversity of available material, and more. Studies investigating 3D-printed denture resins have yielded mixed results. Although many have shown inferior properties to milled and conventional, some have reported comparable results to conventional,[14-16] while others have reported superior properties over both milled and conventional.[16-19] Objective: The objective of this study is to determine if modern 3D-printed denture base materials can serve as a viable alternative to conventional and milled materials through in vitro comparison of flexural strength, fracture toughness, translucency, and stain-resistance of 3D-printed denture base material to milled and conventional heat-polymerized material (control). Materials and Methods: A total of 150 specimens from three 3D-printed denture base material (Dentca Denture Base II, Dentsply Lucitone Digital Print, and Stratasys TrueDent Resin), one milled (I.V. Ivotion Base Milled Denture), and one conventional heat-polymerized (Dentsply Lucitone 199) denture base material were prepared for flexural strength, fracture toughness, translucency, and stain-resistance testing according to ISO protocol 20795-1:2013[20] (n=10/group). Results: 3D-printed material TRDN had the highest flexural strength (FS) value at 82.39 MPa of the group followed by L199, DNTC, IVNB, LPRT in descending order. Their FS values were 73.80, 69.32, 61.80, 47.77 MPa respectively. Fracture toughness (FT) was dominated by two products: L199 & LPRT at 2.03 & 2.01 MPa.m1/2 respectively, which were not significantly different from each other. IVNB was slightly less at 1.87 while the two remaining 3D-printed material, TRDN & DNTC, had the lowest FT values at 0.58 & 0.54 MPa.m1/2 respectively. 60% of specimens exhibited crack-arrest. LPRT & IVNB were the most comparable in translucency to conventional material (12.8% and 20.4% < L199). DNTC was the most translucent material (1.69x > L199), while TRDN was the least translucent (63.3% < L199). DNTC stained the most compared to conventional (1.3x > L199). IVNB was comparable in stain-resistance (6% < staining L199) and not significantly different from it. TRDN stained less than conventional and IVNB (%33 < L199), while LPRT had the most stain-resistance (48.4% < staining L199). Conclusions: 3D-printed denture base materials are evolving rapidly and exhibit notable variations in their properties from one brand and product to another. This is potentially due to differences in printing technologies and product composition rather than manufacturing technique. Both 3D-printed LPRT and TRDN exhibited promising mechanical properties though not always on par with conventional. Therefore, further research is necessary before these materials can be recommended for clinical use. Milled material continue to be a proven alternative to conventional material. Conventional denture resins remain the gold standard for denture base material. Keywords: Denture Base, CAD/CAM, Milled Denture, 3D Printed, Flexural Strength, Fracture Toughness, Color Stability

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