PurposeTo evaluate and compare the mechanical properties (flexural strength and surface hardness) of different materials and technologies for denture base fabrication. The study emphasized the digital technologies of computer‐aided design/computer‐aided manufacturing (CAD/CAM) and three‐dimensional (3D) printing.Materials and MethodsA total of 160 rectangular specimens were fabricated from three conventional heat‐polymerized (ProBase Hot, Paladon 65, and Interacryl Hot), three CAD/CAM produced (IvoBase CAD, Interdent CC disc PMMA, and Polident CAD/CAM disc), one 3D‐printed (NextDent Base), and one polyamide material (Vertex ThermoSens) for denture base fabrication. The flexural strength test was the three‐point flexure test, while hardness testing was conducted using the Brinell method. The data were analyzed using descriptive and analytical statistics (α = 0.05).ResultsDuring flexural testing, the IvoBase CAD and Vertex ThermoSens specimens did not fracture during loading. The flexural strength values of the other groups ranged from 71.7 ± 7.4 MPa to 111.9 ± 4.3 MPa. The surface hardness values ranged from 67.13 ± 10.64 MPa to 145.66 ± 2.22 MPa. There were significant differences between the tested materials for both flexural strength and surface hardness. There were also differences between some materials with the same polymerization type. CAD/CAM and polyamide materials had the highest flexural strength values. Two groups of CAD/CAM materials had the highest surface hardness values, while a third, along with the polyamide material, had the lowest. The 3D‐printed materials had the lowest flexural strength values.ConclusionsGenerally, CAD/CAM materials show better mechanical properties than heat‐polymerized and 3D‐printed acrylics do. Nevertheless, a material's polymerization type is no guarantee of its optimal mechanical properties.

The PAD and EndoActivator system were more successful in reducing the root canal infection than the diode laser and NaOCl syringe irrigation alone.

Highly porous hydroxyapatite (Ca(10)(PO(4))(6)·(OH)(2), HA) was prepared through hydrothermal transformation of aragonitic cuttlefish bones (Sepia officinalis L. Adriatic Sea) in the temperature range from 140 to 220°C for 20 min to 48 h. The phase composition of converted hydroxyapatite was examined by quantitative X-ray diffraction (XRD) using Rietveld structure refinement and Fourier transform infrared spectroscopy (FTIR). Johnson-Mehl-Avrami (JMA) approach was used to follow the kinetics and mechanism of transformation. Diffusion controlled one dimensional growth of HA, predominantly along the a-axis, could be defined. FTIR spectroscopy determined B-type substitutions of CO(3) (2-) groups. The morphology and microstructure of converted HA was examined by scanning electron microscopy. The general architecture of cuttlefish bones was preserved after hydrothermal treatment and the cuttlefish bones retained its form with the same channel size (~80 × 300 μm). The formation of dandelion-like HA spheres with diameter from 3 to 8 μm were observed on the surface of lamellae, which further transformed into various radially oriented nanoplates and nanorods with an average diameter of about 200-300 nm and an average length of about 8-10 μm.

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Objectives to determine the mechanical properties of hybrid and high-viscosity glass ionomer cements. Compressive strength and hardness of three glass ionomer cements (GIC) were measured: Ketac ™ Universal Aplicap ™, EQUIA Fil® and EQUIA FORTE Fil®, and the SEM sample analysis were performed. Materials and Methods The samples for measuring the compressive strength were prepared using silicone molds with standard dimensions of 6 mm x 4 mm and stored in deionized water for five days, while the samples for hardness measurement were prepared using Teflon molds with a cylindrical opening in the middle, dimensions 2 mm in height and 5 mm in width. For each material, one sample was made (n = 1) and stored in deionized water at 37ºC for 25 days. A representative sample of each material was analyzed using SEM. For the comparison of obtained values, the ANOVA test was used, while Tukey test was used for the multiple comparison. Results There were no significant differences between the compressive strength of the three tested materials (p <0.05). The hardness values were: 157 HV0,2 for Ketac ™ Universal Aplicap ™, 47 HV0,2 for EQUIA Fil® and 39 HV0,2 for EQUIA FORTE Fil®, respectively, and were significantly different, implying that Ketac ™ Universal Aplicap ™ has much higher hardness values than the other materials tested. SEM sample analysis revealed similar fracture modes of the tested materials. Conclusion It was concluded that there were no statistically significant differences in compressive strength and fracture modes between the tested materials, while Ketac ™ Universal Aplicap ™ hardness results were significantly higher than the ones measured for EQUIA Fil® and EQUIA FORTE Fil®.