•Translucency and crystallography of four highly translucent zirconia were assessed.•The effect of Al2O3-sandblasting on zirconia was investigated.•Translucency and crystallography of the zirconia ...grades differed significantly.•Al2O3-sandblasting resulted in a similar surface roughness for all zirconia grades.•Al2O3-sandblasting altered the phase composition and residual stress.
To assess the influence of alumina sandblasting on four highly translucent dental zirconia grades.
Fully sintered zirconia disk-shaped specimens (15-mm diameter; 0.5-mm thickness) of four highly translucent yttria partially stabilized zirconia (Y-PSZ) grades (KATANA HT, KATANA STML, KATANA UTML, Kuraray Noritake; Zpex Smile, Tosoh) were sandblasted with 50-μm alumina (Al2O3) sand (Kulzer) or left ‘as-sintered’ (control) (n=5). For each zirconia grade, the translucency was measured using a colorimeter. Surface roughness was assessed using 3D confocal laser microscopy, upon which the zirconia grades were statistically compared for surface roughness using a Kruskal–Wallis test (n=10). X-ray diffraction (XRD) with Rietveld analysis was used to assess the zirconia-phase composition. Micro-Raman spectroscopy was used to assess the potentially induced residual stress.
The translucency of KATANA UTML was the highest (36.7±1.8), whereas that of KATANA HT was the lowest (29.5±0.9). The ‘Al2O3-sandblasted’ and ‘as-sintered’ zirconia revealed comparable surface-roughness Sa values. Regarding zirconia-phase composition, XRD with Rietveld analysis revealed that the ‘as-sintered’ KATANA UTML contained the highest amount of cubic zirconia (c-ZrO2) phase (71wt%), while KATANA HT had the lowest amount of c-ZrO2 phase (41wt%). KATANA STML and Zpex Smile had a comparable zirconia-phase composition (60wt% c-ZrO2 phase). After Al2O3-sandblasting, a significant amount (over 25wt%) of rhombohedral zirconia (r-ZrO2) phase was detected for all highly translucent zirconia grades.
Al2O3-sandblasting did not affect the surface roughness of the three highly translucent Y-PSZ zirconia grades, but it changed its phase composition.
Background: Surface roughness of dental implants impacts the survival of adult periodontal stem cells and rate of differentiation. This research was conducted to test how human periodontal ligament ...stem cells behaved on yttria stabilized tetragonal zirconia polycrystals and polyetheretherketone (PEEK) discs with different surface topographies.
Methods: Discs roughening was prepared by sandblasting. Stem cells were cultivated on zirconia discs with a polished surface, PEEK discs with a polished surface, sandblasted zirconia discs and sandblasted PEEK discs. Cells viability was assessed after 24, 48, 72 hours. Scanning electron microscopy was used to examine the adherence and attachment of cells. Osteoblastic differentiation capacity was studied by checking the mineralization clusters development through alizarin red S staining and alkaline phosphatase assay. ANOVA and the Tukey post hoc test were used for the statistical analysis.
Results: Polished PEEK discs showed lower cell viability, whereas roughened sandblasted zirconia and PEEK discs showed the highest proliferation rates and cell viability percent. The osteogenic differentiation was enhanced for rough surfaces in comparison to polished surfaces. Sandblasted zirconia and PEEK discs showed a markedly increased mineralized nodule development and ALP enzyme activity compared to the polished surface and control.
Conclusions: Micro- topographies creation on the PEEK implant surface enhances stem cell attachment, viability, and osteogenic differentiation.
Water repellency is often generated by taking advantage of surface textures and low surface energy coatings such as the one afforded by long perfluorinated side‐chains polymers. However, new ...regulations are phasing out these polymers because of their related health and safety hazard concerns. This is a particular challenge for water‐repellent fabrics as consumers expect safer products with stable performance and new functionalities. In this work, an approach is developed that allows for iCVD deposition of durable, conformal short fluorinated polymers stabilized with a crosslinking agent. As a result, high hydrophobicity and low liquid adhesion are achieved simultaneously while maintaining initial substrate breathability. It is explained why this polymeric coating—1H,1H‐perfluorooctyl methacrylate co divinylbenzene—exhibits remarkable hydrophobic properties amidst a wide range of other possible candidates. In order to further enhance the dynamic water repellency performance, the chemical treatment is combined with physical texturing—obtained through microsandblasting, a process particularly suitable for fabrics—thus making this combined approach a suitable candidate to meet the industrial needs. This work paves the way for the development of environmentally friendly, highly repellent coatings for large volume production and the application of roll‐to‐roll coating techniques, and multifunctionalization of fabrics and wearable devices.
Initiated chemical vapor deposition (iCVD) of conformal short fluorinated polymers stabilized with a crosslinking agent is successfully carried out with 1H,1H‐perfluorooctyl methacrylate crosslinked with divinylbenzene. The ultrathin, grafted, and multifunctionalization aspect of iCVD leads to breathable, low material usage, durable, and EPA acceptable liquid repellent coatings particularly suited for substrates as diverse as fabrics, paper, and nanotextured silicon.
Titanium Grade 4 (G4) is the most commonly used material for dental implants due to its excellent biocompatibility and mechanical properties. However, titanium implants require a rough surface that ...can increase the biomechanical potential of implant–bone contact and affect protein adsorption speed. In this work, the effect of sandblasting of the Ti G4 surface on the long-term corrosion resistance in artificial saliva of pH = 7.4 at 37 °C was studied. The X-ray diffraction (XRD) single-{hkl} sin2ψ method was used to measure the sandblasted Ti residual stress. In vitro corrosion resistance tests were conducted for 21 days using the open circuit potential method, polarization curves, and electrochemical impedance spectroscopy. Using the Kelvin scanning probe, the electron work function was determined. Analysis of the obtained results showed an improvement in the corrosion resistance of the sandblasted Ti G4 compared to Ti with the machine surface. The increase in corrosion resistance was related to the residual compressive stress of 324.7 MPa present in the sandblasted Ti surface. Sandblasting caused plastic deformation of the Ti surface, which resulted in the improvement in mechanical properties, as evidenced by the increase in the hardness of the sandblasted Ti compared to Ti with the machine surface.
Highlights • We assess the rough polished, Al2 O3 or tribochemical silica sandblasted zirconia. • These surface treatments improve the aging resistance of Y-TZP zirconia. • Ce-TZP/Al2 O3 zirconia are ...not affected by low-temperature degradation. • Surface treatments slightly decrease the aging resistance of Y-TZP/Al2 O3 zirconia.
The purpose of this study was to determine the effect of one-wall elimination of the abutment and also the surface treatment of the abutment on the retention of cement-retained, implant-supported ...zirconium oxide copings.
In this experimental study, four straight abutments were connected to four implant analogs (DIO, UF, Busan, Korea) with 35 Ncm torque. They are mounted vertically in resin blocks. Abutments were prepared as following groups: A) abutment was used in its intact standard form as a control group. B) 4 mm of the flat wall was removed to produce an abutment with 3 walls. C) The abutment surface was abraded with 50 µm AL2O3 powder. D) 4 mm of a flat wall of the abutment was removed, then the abutment surface was abraded with 50 µm AL2O3 airborne particle.10 zirconium oxide copings were made. Samples were cemented with temp bond NE to abutments. The retention of copings was measured before and after incubation using the universal testing machine. T-test, one-way ANOVA, and Post Hoc Tukey Test were used for statistical analysis of data.
In all groups, retention was decreased after thermocycling (
≤0.001). 3 wall abutments had less retention than the control group before thermocycling. A significant difference was detected between 3 wall abutments and 4 walls of sandblasted abutments before thermocycling. After thermocycling, no difference in retention was seen between groups.
Thermocycling significantly reduces the retention of implant-supported ceramic copings. Sandblasting abutments with 50 µm AL2O3 air-borne particles did not increase the retention of ziconium oxide copings which were cemented with temp bond NE. One wall elimination of abutment decreased the retention of zirconia copings.
Retention, crown, abutment, zirconia coping, sandblasting.
This paper presents a study on evaluation of seismic performance of shear-deficient beam column joints (BCJs) strengthened by ultra-high performance fiber reinforced concrete (UHPFRC). Normal ...concrete BCJs having deficiencies in resisting the seismic action were cast, strengthened with a thin layer of UHPFRC, and tested under seismic loading. Two different methods were used for strengthening the normal concrete BCJ specimens consisted of: i) sandblasting the normal concrete substrate surface of BCJs and in-situ casting of a 30 mm thick UHPFRC jacket and ii) bonding 30 mm thick prefabricated UHPFRC plates to seismically deficient BCJ using epoxy resins and special fillers. The performance of UHPFRC jacketing in strengthening the seismically deficient BCJs was experimentally evaluated under reverse cyclic loading using displacement control approach keeping column axial load constant at 150 kN. The analysis of test results showed that the first method of strengthening was highly effective in terms of shear capacity, deformation capacity, stiffness characteristics and energy dissipation capacity, as compared to the second method.
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