These findings are expected to be highly important and useful when TiNb alloys are considered as materials for hip/knee articular joint implants.
  The objectives of this study were to compare the in vitro, laboratory aging, fracture strength, failure mode and reparability of molars restored with lithium disilicate inlays and overlays in conjunction with or without immediate dentin sealing (IDS).
 
  Forty extracted, sound human molars were selected and divided into four groups 1) Inlays with IDS; 2) Inlays without IDS; 3) Overlays with IDS; 4) Overlays without IDS. Standard MOD preparations were made (3mm wide, 5mm deep) and in groups 2 and 4, all the cusps were reduced by 2mm. Directly following tooth preparation, IDS was applied in specimens belonging to groups 1 and 3. The indirect restorations were luted with a heated composite. The restored teeth were subsequently challenged during aging (1.2 million cycles) and thermocycling loading (8000 cycles, 5-55 degrees C). Subsequently, the fracture strength was tested by a load to failure test at 45°. A failure analysis was performed using light- and scanning electron microscopy. The results were analyzed ay preparation improve overall fracture strength. Inlays with IDS and overlays without IDS didn't differ in fracture strength. Both inlays and overlays are strong enough to withstand physiological chewing forces.A facile procedure has been devised to develop a novel dentin bonding system containing poly (acrylic acid)-grafted-silanized fumed silica particles as reinforcing filler, with high stability of nanoparticle dispersion and enhanced bond strength and mechanical properties. In the first step, the silanization of fumed silica nanoparticles was performed in the following conditions (i) ethanol-water solution with a pH of 5 and (ii) cyclohexane with a pH of 9 using trimethoxysilylpropyl methacrylate (γ-MPS) as a reactive silane coupling agent. FTIR and TGA analyses confirmed the presence of silane in the resultant structure and enhanced dispersion stability of modified particles was proved by a separation analyzer and also zeta potential analyses. In the second step, free radical polymerization of acrylic acid monomers in the presence of silanized nanoparticles was carried out and poly (acrylic acid) -grafted- silanized fumed silica were acquired. The flexural strength and fracture toughness of the adhesive contaiated into the dentin tubules proved by the SEM micrographs in microtensile bond strength test.This study aimed to evaluate the influence of loading frequency on the fatigue mechanical behavior of adhesively cemented polymer-infiltrated ceramic-network (PICN) and lithium disilicate (LD) simplified monolithic restorations. Thirty (30) disc-shaped specimens (Ø = 10 mm; thickness = 1.0 mm) of each ceramic material (PICN - Enamic, Vita Zahnfabrik or LD - IPS e.max CAD, Ivoclar Vivadent) were produced and adhesively cemented onto dentin analogue discs made of fiber and epoxy resin material (Ø = 10 mm; thickness = 2.0 mm). PICN and LD cemented assemblies were randomly allocated into 2 groups (n = 15) according to the loading frequency used for the fatigue testing (20 Hz or 2 Hz), composing the PICN_20, PICN_2, LD_20 and LD_2 testing groups. Fatigue tests were run using the step-stress approach (initial load = 200 N; step-size = 100 N; 10,000 cycles per step) and the collected data (fatigue failure load - FFL and number of cycles for failure - CFF) were analyzed by survival tests (Kaplan Meier and Mantel-Cox) and Weibull analysis. Fractographic analysis of failed specimens were also performed. No statistically significant differences were detected in relation to FFL and CFF between the groups within the same ceramic material (PICN_20 1127 N/102,667 cycles = PICN_2 1120 N/102,000 cycles; LD_20 980 N/88,000 cycles = LD_2 900 N/80,000 cycles). All failures were radial cracks in the cementation surface. Therefore, the use of a 20 Hz loading frequency shows to be a viable alternative to accelerate cyclic fatigue tests without affecting the fatigue mechanical behavior and the failure pattern of simplified restorations made of lithium disilicate glass ceramic or polymer infiltrated ceramic network bonded to the dentin analogue.This in situ/in vivo study aimed to evaluate the effects of erosion on the surface microhardness, substance loss, and surface roughness of CAD/CAM restorative materials and human enamel. This study used a 2-treatment (14 days each) crossover design with 8 healthy volunteers. Each volunteer wore an intraoral appliance containing 3 CAD/CAM restorative material specimens [IPS e.max CAD, Lava Ultimate CAD/CAM Restorative, and a poly (methyl methacrylate) (PMMA) block for CAD/CAM] and 1 human enamel specimen. The specimens were subjected to in vivo erosion cycles by rinsing with 150 ml of cola drink (4 × 5 min/day) for 14 days. The surface microhardness, substance loss, and surface roughness of the specimens were measured at baseline (T1), day 7 (T2) and day 14 (T3). The data were statistically analyzed using repeated measures ANOVA and Tukey's test (α = 0.05). After erosion, significant increases in substance loss and surface roughness were observed for enamel, though the surface roughness and substance profile of the tested restorative materials remained unchanged.  https://www.selleckchem.com/products/oicr-9429.html  Erosion significantly decreased the surface microhardness of all materials. For IPS e.max and Lava Ultimate, a significantly higher percentage of surface microhardness loss (%SMHl) was found at T3 than at T2, while no significant difference was found between T2 and T3 for enamel and the PMMA block. In conclusion, CAD/CAM restorative materials showed smaller changes in surface roughness and the surface profile than human enamel after in situ/in vivo erosion. However, CAD/CAM restorative materials and human enamel showed similar changes in surface microhardness after in situ/in vivo erosion.We measured wear and creep in conventional tibial inserts retrieved after total knee arthroplasty by using Raman spectroscopy. The Raman spectra of thirteen tibial inserts retrieved after total knee arthroplasty with a mean in vivo time of 34.3 months were confocally measured along their bearing subsurface, and then from bearing surface to backside after cutting. The amounts of creep, wear, and wear rate in the medial and lateral load zone were computed from the full-width at half-maximum of a selected Raman band as a characteristic parameter related to strain. In all retrievals, the strain was higher than that of pristine samples at the bearing subsurface, and we observed a correlation between full-width at half-maximum and body weight/body mass index in both load zones. The amount of total penetration, creep, and wear were 0.27 ± 0.21, 0.082 ± 0.031, 0.19 ± 0.18 mm in the medial load zone and 0.22 ± 0.18, 0.080 ± 0.040, 0.14 ± 0.14 mm in the lateral load zone, respectively. The amount of wear in both load zones was strongly correlated with the in vivo time.