Bond Strength between CAD/CAM PMMA Denture Base Resins and Characterisation Composites

Abstract

Aim: To measure the bond strength between two different CAD/CAM PMMA denture base resins and three different types of gum characterisation composites. Materials and Methods: CAD/CAM single cross-linked (Telio CAD) and double cross-linked (Vivodent CAD) resins were prepared, obtaining a total of 180 bar specimens. Each specimen was prepared according to the manufacturer’s instructions. The specimens were bonded to three different characterisation composites with varying viscosities; Kulzer Pala-creactive (P), Ivoclar SR Nexco (S), Shofu Ceramage (F). All the specimens were then tested using a chevron-notched three-point bond strength test in a universal testing machine to obtain fracture energy release toughness (MPa√m) and bond strength (MPa). The specimens were thermocycled to simulate 6 and 12 months of ageing in vivo. The results were statistically analysed (SPSS). The fractured surfaces of the tested specimens were examined with a scanning electron microscope (SEM) to evaluate the failure modes. Results: Pala-creactive characterisation composites showed the highest overall bond strength (3.49 ± 0.86 MPa) and fracture toughness (1.59 ± 0.34 MPa√m) when bonded to both CAD PMMA denture resins, which were statistically higher than the values obtained when they were bonded to Telio (p < 0.001). The Ceramage composite showed the lowest bond strength (1.05 ± 0.59 MPa) and fracture toughness (0.47 ± 0.4 MPa√m). The dominant mode of failure for all groups was mixed. Conclusion: Single cross-linked PMMA (Telio) showed a higher overall bond strength compared to double cross-linked PMMA when bonded to three different characterisation composites. Telio CAD showed a clear bond strength decrease after 6 and 12 months of artificial ageing, while Vivodent CAD showed a bond strength increase.

Effect of Hygiene Protocols on the Mechanical and Physical Properties of Two 3D-Printed Denture Resins Characterized by Extrinsic Pigmentation as Well as the Mixed Biofilm Formed on the Surface

“…Some studies present the results of the behavior of printed resins after exposure to pigmented solutions, such as coffee and red wine [11,12]. However, literature is scarce regarding the behavior of base resins characterized and exposed to long periods of hygiene protocols [13,14].…”

Determination of the degree of conversion, the diffuse reflectance, and the color stability after different aging processes of gingiva‐colored composite resins

“…Indirect composite resins are defined as laboratory‐type composite materials, 6 prosthetic composites, or characterization composites 7 . These materials are polymerized outside the oral environment employing heat, light, vacuum, and nitrogen atmosphere 8,9 …”

“…2,4 Indirect composite resins are defined as laboratory-type composite materials, 6 prosthetic composites, or characterization composites. 7 These materials are polymerized outside the oral environment employing heat, light, vacuum, and nitrogen atmosphere. 8,9 Similar to other composite materials, they are composed of an oligomer matrix made of resin that is typically based on bisphenol A-glycidyl methacrylate (bis-GMA) or urethane dimethacrylate (UDMA) and silanized inorganic fillers like silicon dioxide (silica), barium, quartz, or zirconia.…”