Adhesion of Denture Characterizing Composites to Heat‐Cured, CAD/CAM and 3D Printed Denture Base Resins

Abstract

Purpose To measure the adhesion of the denture characterizing composite to heat‐cured, CAD/CAM and 3D printed denture base resins. Methods and Materials Two different denture characterizing composites with different viscosities (SR Nexco; high viscosity (SR) and Kulzer Cre‐active; low viscosity (K)) and three denture base resins (Heat cure, CAD‐milled and 3D printed) were investigated. 60 beams (25 × 4 × 3 mm) were fabricated for each denture base resin; 30 were bonded to SR and 30 to K to form a beam 50 × 4 × 3 mm. These were further divided (n = 10/group) to simulate the effects of 0, 6, and 12 months intraorally via thermocycling. The beams were subjected to a 4‐point bend test using the chevron‐notched beam method. Fracture toughness K1C (MPa ·m1/2) and flexural bond strength (MPa) were calculated. All specimens were analyzed for the mode of failure under the light microscope and selected specimens under scanning electron microscope. Results were statistically analyzed using ANOVA (SPSS Ver 25). Results The mean K1C was highest for the SR composite bonded to the heat‐cured denture resin group (0.28 ± 0.11), followed by CAD/CAM (0.18 ± 0.04) and 3D printed groups (0.23 ± 0.16). Differences were not statistically significant (p = 0.268). Within each group, aging showed no statistical significance between the mean K1C and flexural bond strength (p = 0.209). The mean K1C for the K composites bonded to the three different denture bases were significantly lower compared to the SR group (p < 0.001). The mean K1C for the heat‐cured denture resin group was (0.21 ± 0.1), followed by CAD/CAM (0.13 ± 0.04) and 3D printed groups (0.03 ± 0.02). Within each of the K group, aging showed a statistical significance for both the mean K1C and flexural bond strength (p = 0.002). Conclusion The high viscosity SR showed significantly higher K1C and flexural bond strength to the lower viscosity K when bonded to heat‐cured, CAD‐milled and 3D printed denture base resins. Heat‐cured denture base resins produced the highest K1C and flexural bond strength when bonded to two different types of characterizing composites.

Comparison of shear bond strength of CAD/CAM and conventional heat-polymerized acrylic resin denture bases to auto-polymerized and heat-polymerized acrylic resins after aging

“…Regarding the adhesion of CAD/CAM and conventional denture bases to other materials, Choi et al . compared the bond of denture characterizing composites to heat-polymerized and CAD/CAM denture base resins and demonstrated better bond strengths of characterizing composites with CAD/CAM bases under thermocycling ( 37 ). The same authors evaluated the bond strength of acrylic denture teeth ( 27 ) and resilient denture liners ( 16 ); they reported improved bond strengths of these materials to heat-polymerized compared with CAD/CAM denture base.…”

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

“…Various methods are used to measure the strength of the bonds between composites and denture resins on the basis of shear bond strength or micro-tensile bond strength [11][12][13]. The fracture energy method evaluating the fracture toughness is reported to be the most suitable for dental materials due to its focus on debonding stresses and interface [11,14,15]. CAD/CAM systems have several benefits as concerns their production and mechanical properties, such as short working time, strong and long-lasting materials with high-density polymers and highly crosslinked PMMA resin systems, which exhibit different mechanical properties due to their chemical composition.…”

Comparison of Surface Roughness and Color Stability of Different Denture Characterizing Composite Resins: The Effect of Different Surface Treatments

“…The mechanical properties, contour and color of the soft tissue are as important in these prostheses as the shape, color and general appearance of the teeth. 2,3 With the progress of computer-aided design and computeraided manufacturing (CAD-CAM) technology and threedimensional printing, 3D dentures are widely used in the construction of restorations such as removable, complete and hybrid prostheses. 4 Similarly to conventional heat-cured dentures, CAD-CAM and 3D dentures often have a monolithic and flat appearance.…”

“…In recent years, gingiva-colored denture characterizing composite resins have been developed to reconstruct the gingival structure and the character of the mucosa. 2,3 These composite resins which offer an esthetic alternative have improved mechanical properties and very low shrinkage because of the increased filler content. In addition, their shape, color, and texture can be controlled and easily repaired.…”

“…22,23 However, the long-term performance of sealant agents has not been fully reported. Moreover, although the adhesion of denture characterizing composite resins to different denture base resins has been examined, 3 the authors are unaware of studies that evaluated the effect of different surface treatments on the color and surface of denture characterizing composite resins due to long-term use.…”