Flexural strength, surface roughness, micro-CT analysis, and microbiological adhesion of a 3D-printed temporary crown material

Abstract

Objective: To evaluate the thermocycling effect of 3D-printed resins on exural strength, surface roughness, microbiological adhesion, and porosity.Materials and methods: Speci cally, 150 bar specimens (8 × 2 × 2 mm) and 100 blocks (8 × 8 × 2 mm) were made and divided among ve groups, according to two factors: "material" (AR: acrylic resin, CR: composite resin, BIS: bis-acryl resin, CAD: CAD/CAM PMMA resin, and PRINT: 3D-printed resin) and "aging" (non-aged and aged -TC). Half of the samples from each group were subjected to thermocycling (10,000 thermocycles; 5-55 °C), and the rest were stored in water (37 ºC) for 24 h. The bars were then subjected to a mini exural strength (σ) test (1 mm/min; 100kgF). All the blocks were subjected to roughness values (Ra, Rq, and Rz). The non-aged blocks were subjected to porosity analysis (micro-CT (n=5)) and fungal adherence (n=10). The data of σ (MPa) and Ra, Rq, and Rz(µm) were statistically analyzed using two-way ANOVA and Tukey's test. Weibull analysis was performed to verify the reliability of the σ data. Fungal adhesion (log CFU/mL) data were analyzed using one-way ANOVA and Tukey's test.Results: For exural strength, ANOVA showed that "material" and "aging" factors were statistically signi cant (p<0.0001). The mean exural strength ranged from 49.87 MPa to 118.23 MPa between the experimental groups. The BIS group (118.23±16.26A) presented higher σ value than the AR group (89.60±9.38BC), whereas the PRINT group (49.87±7.55E) had the lowest mean of the exural strength (Tukey, a=0.05). All groups showed a decrease in σ after thermocycling, except for the PRINT group, which showed signi cantly increased exural strength after aging (PRINTTC:81.33±20.38CD). The Weibull modulus for the CRTC was signi cantly lower than those of the other groups. The AR group showed higher roughness values than the BIS group, regardless of age (p<0.0001). Porosity analyses revealed that the AR (1.369%) and BIS (6.339%) groups presented the highest porosity values among the experimental groups and that the CAD group (0.002%) had the lowest porosity. Cell adhesion was signi cantly different between the CR (6.81) and CAD (6.37) groups (p=0.036).Conclusion: Thermocycling reduced the exural strength of most provisional materials evaluated, except for 3D-printed resin. However, it did not in uence the surface roughness of each material. Moreover, Candida albicans adherence and porosity varied among materials.Clinical relevance: 3D-printed resins are promising materials for clinical applications because they have good mechanical properties and low fungal adhesion.

The flexural strength of 3D-printed provisional restorations fabricated with different resins: a systematic review and meta-analysis

“… Ultraviolet polymerization Digitally produced intermediate materials outperformed traditionally polymerized materials in terms of mechanical characteristics NA [ 31 ] 3-point flexural bend test SLA = 48.9 SLS = 77.3 Acrylic resin = 69.2 Bis-acryl resin = 75 Polymerized with light SLS resin demonstrated positive outcomes, showcasing higher maximum flexural strength Orientation angles and new types of resins were missing. [ 30 ] Universal testing machine Graphy = 329.3 NextDent = 177.8 NA 3D-printed resin crowns might present a viable alternative for fabricating fixed prostheses for primary teeth Study design [ 38 ] 3-point flexural bend test 3DCS = 143 3DOS = 141 CHP = 76 CAP = 88 Polymerization The tested 3D-printed interim resins outperformed the traditional resins A limited number of materials were investigated and tested [ 32 ] 3-point flexural bend test Cosmos Temp = 56.83 Evolux PMMA = 111.76 Structur 2 SC = 87.34 post-polymerized with 3000 flashes of ultraviolet light Although the mechanical qualities of the milled resin were more significant or comparable to those of the bisacrylic resin, the 3D-printed resin was statistically inferior to both the milled and bisacrylic resins Orientation angles were not considered [ 33 ] 3-point flexural bend test 3D printed = 81.33 Acrylic resin = 72.90 Nanofilled composite resin = 34.97 CAD/CAM PMMA resin = 94.63 Bis-acryl composite resin = 91.57. NA Except for 3D-printed resin, thermocycling lowered the flexural strength of most temporary materials NA [ 35 ] 3-point flexural bend test Before accelerated aging (pre-aging), the flexural strength of the A2 group (151 ± 7) was greater (p < 0.05) than that of the other groups.…”

“…Most studies were conducted in South Korea [ 1 , 29 , 30 ] and Brazil [ 31 – 33 ], followed by Saudi Arabia [ 34 , 35 ], China [ 36 ], Turkey [ 37 ], Romania [ 38 ], India [ 39 ], and Germany [ 40 ]. Most studies have employed Digital Light Processing (DLP) [ 30 , 33 , 35 , 38 , 40 ], stereolithography (SLA) [ 32 ], Both DLP and SLA [ 1 , 29 , 34 ], Fused Deposition Modeling (FDM) [ 1 ], and mono-liquid Crystal Display (LCD) [ 36 ], with a variety of printed materials, such as acrylic, composite resin, and methacrylate oligomer-based materials. The layer thickness was 50 μm in most studies [ 30 , 34 , 35 , 40 ], and the wavelength/light intensity varied across studies, with a maximum of 405 nm/13.14 mW/cm 2[ 34 ].…”

Investigation of adhesion status of Candida species to the surface of resin materials produced at different angles with additive manufacturing

“…The average surface roughness value (Ra) was determined by measuring (µm) three regions identified at the center of the sample surface. Measurements were made at a speed of 0.5 mm/sec, with a cut-off measurement length of λc = 0.25 [ 18 ].…”

Visual Versus Digital Color Determination of 3D-Printed Teeth as an Exercise in Dental Students’ Education

“…Espinar et al confirmed that the optical properties of CAD/CAM hybrid 3D-printed restorations depend on thickness and building orientation [10]. Current in vitro studies on CAD/CAM hybrid 3D-printed restorations are mainly limited to static tests evaluating intrinsic material properties, such as material strength [11][12][13][14][15][16][17][18][19][20], resilience [16], fracture toughness [16,19], microhardness [11,21,22], wear [23], surface roughness [18,22,24], and modulus of elasticity [11,17]. No studies are available regarding the color determination of CAD/CAM hybrid 3D-printed teeth.…”