Laminated veneer lumber (LVL) and laminated veneer board (LVB) panels from jabon wood (Neolamarckia cadamba) were impregnated with fire retardation substances, namely diammonium phosphate (DAP) and ...sodium silicate (SS). Prior to testing, the boards were conditioned in relative humidity (RH) of 65% and a temperature of 25 °C. The moisture content (MC), bending strength tests in flat wise position, and bonding tests were conducted in accordance with the Japanese Agricultural Standard (JAS:2008). Density tests and hardness tests were conducted in accordance with ASTM D143 standard (2003) in 50 mm x 50 mm. Thickness-swell shrinkage tests were conducted in accordance with the standard BS EN 317:1993, and fire resistance was tested under PS 1-19 standard. The use of 20% DAP and SS solution on jabon wood using impregnation methods affected some of the properties of the panels, especially the moisture content, density, and bonding strength of LVL and LVB compared to the control panels. Both DAP and SS impregnation increased the density. The treatments showed promise for resisting fire, as well as increasing the moisture content and increasing the density compared to the control.
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The plastic film of the new plastic film reinforced pliable decorative veneer (PRPDSV) is used as a flexible reinforcement material and an adhesive material. It has good water resistance, ...impermeability, simple preparation and finishing processes, and no formaldehyde release. However, warpage phenomenon during hot pressing has been a bottleneck problem restricting its industrial development. In order to solve this problem solve, the study proposed a concave, and convex molds method, established an elastic–plastic FEA model of hot pressing processes of the PRPDSV using concave and convex molds with static/general static solution module in the nonlinear ABAQUS, and researched the effect on the performances of the PRPDSV from the parameters of temperature, pressure, and mold curvature radius theoretically and verified experimentally. Analysis results showed that the surface forming temperature had a great effect on warpage control for PRPDSV. The higher the temperature is, the smaller the curvature radius of the corresponding mold will be and the better the warpage will be. The curvature radius of the molds had a significant effect on the warpage control. Under the conditions with the same hot pressing parameters, the smaller the curvature radius is, and the better control on the warpage for the PRPDSV will be.
Modified polyethylene film and decorative veneer hot‐pressing curved surface molding assembly (1‐ Concave die, 2‐ Anti‐sticking plate, 3‐ PE film layer, 4‐ Decorative veneer layer, 5‐ Terrace die).
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Background:
Partial laminate veneers (PLV) have been accepted widely among both clinicians and patients with their favorable specifications, such as conservativeness, superior esthetics, bond ...strength and durability, for three decades. Various esthetic and functional impairments spreading in a wide range may be restored with veneers instead of full contour crowns.
Objective:
Although advantages, partial laminate veneers are not free from complications and various factors can influence the service duration of these restorations.
Methods:
An electronic Pubmed/Medline and Google Academic search was conducted without time restriction, providing information on porcelain laminate veneer’s failure rate and survival. Assessment of the identified studies was performed by two independent reviewers. Clinical service durations and various types of failures were evaluated.
Results:
Debonding, fracture, discoloration of the porcelain; staining or disintegration of tooth-porcelain margin; hypersensitivity, secondary caries, pulp necrosis and the periodontal responses were the more frequently studied failures. The mean CFR was found as 8,22% per study. Enamel substrate, incisal overlapping and lithium disilicate veneers presented lower failure rates in comparison with dentine substrate, non-overlapping and feldspathic veneers.
Conclusion:
PLV’s have high survival rates. The overall survival of PLV restorations can be affected by several prognostic variables.
Commercially available resin cements consist of various filler sizes, filler content and monomers, and it is unclear which of these factors have the greatest effect on the color stability of laminate ...veneers.
To evaluate the color stability of lithium disilicate-reinforced laminate veneers inserted with three commercial resin cements with various filler sizes/contents and monomers upon accelerated aging.
Veneers were fabricated and cemented on resin abutments using three commercially available resin cements comprised of two different monomers and varying filler sizes/contents: 1) triethylene glycol dimethacrylate, TEGDMA (RelyX™ Veneer = 0.6 µm/66 %, Calibra® Esthetic Light Cure =1.2 µm/65 %); and 2) urethane dimethacrylate, UDMA (Variolink Esthetic LC = 0.1 µm/38 %). A total of 60 specimens were fabricated (n = 20 for each cement). The relative number of particles (N) and relative surface area (A) were calculated for each filler size/content. Color coordinates (L*, a*, b*) were measured, and color change (ΔE00) was calculated after cementation and following aging at 150, 300, 450, and 600 h using xenon light. Differences in color coordinates and color change were determined using repeated measures ANOVA followed by Tukey's post hoc test (α = .05). A post-hoc power analysis was performed to confirm reliability of the results.
Based on a post-hoc power analysis of a repeated measures ANOVA with two between-factors and 1 within-factor, we had 89 % power to detect a difference of effect by cement type, 10 % power to detect a difference by shade, and 100 % power to detect a difference of effect by aging. The UDMA-based cement (0.1 µm/38 %) was least affected by aging, despite having the largest number of particles (N = 1010) and largest particle surface area (A = 7.02). The TEGDMA-based cements exhibited a significant color change, with 0.6 µm/66 % (A = 2.03, N = 8.12) producing a larger ΔE00 than 1.2 µm/65 % (A = 1.00, N = 1.00).
Among the commercial cements tested, UDMA-based resin (0.1 µm/38 %) provided better color stability than TEGDMA-based resin cements. The color change after aging was affected by the relative surface area and relative number of particles for the TEGDMA-based resin cement (0.6 µm/66 % and 1.2 µm/65 %), with a larger surface area and a higher relative number of particles, accelerated color change with aging. The present study demonstrates a novel approach to determine color stability for any resin cement with particulate filler.
The dental practitioner should be selective in choosing a commercial light cure cementation product for laminate veneers, as UDMA containing resin cement is more resistant to color changes over time than TEGDMA, regardless of the filler size/content.
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The development of thin-type bamboo bundle laminated veneer lumber (T-BLVL) represents a significant advancement in environmentally friendly and sustainable building materials. However, the ...application of T-BLVL is still hindered by poor dimensional stability and low mechanical strength. In this study, the delignified thin-type bamboo bundle laminated veneer lumber (D-T-BLVL) was prepared through the partial delignification of bamboo bundles and the synergistic effects of phenolic resin (PF). These effects included gluing, strengthening, and waterproofing. D-T-BLVL exhibited high strength, dimensional stability, and a remarkable thickness of only 5 mm. After the removal of 26 % lignin, the porosity of bamboo bundles increased by 117 % compared with natural bamboo bundles, facilitating enhanced PF infiltration. D-T-BLVL exhibited a bending strength of 281.84 MPa, representing an 83.75 % increase over that of T-BLVL (153.38 MPa). Additionally, the water absorption thickness expansion rate of D-T-BLVL (3.37 %) was only approximately 1/4 times that of T-BLVL (13.30 %). The development of D-T-BLVL provides valuable guidance for developing wind turbines, infrastructures, and other advanced technologies.
•Partial delignification (26 %) enlarged internal pores (117 %) of bamboo bundle.•Permeability of bamboo bundles increased by 20 times via delignification.•PF played a triple synergistic role as glue, strengthen, and waterproof in D-T-BLVL.•D-T-BLVL has a higher strength and dimensional stability than T-BLVL.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Laminated veneer lumber (LVL) and modified grain orientation of LVL (LVB) are composite products made from veneer that are predicted to replace construction timber. The purpose of this study was to ...determine the physical and mechanical properties of LVL and LVB of mahoni (Swietenia macrophylla), manglid (Manglietia glauca), and gmelina (Gmelina moluccana) and to compare their characteristics. The results showed that the physical and mechanical properties of LVL and LVB generally meet the standards for use in construction. Differences in the properties of LVL and LVB occurred in the properties of hardness and screw tests, while the other properties were similar. The parallel fiber direction was better in terms of adhesive strength, while the compaction density was slightly higher than LVL. The LVL flexural strength was better than LVB in flat and edge test directions. This difference correlates with the adhesive strength in the shear strength test due to the different orientation of the fiber directions.
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This case report presents a new technique for sectional veneer fabrication and diastema restoration with a prefabricated composite veneer. For the purpose of diastema restoration, a prefabricated ...sectional veneer provides the same benefits of a traditional ceramic sectional veneer (highly esthetic restoration with no need for tooth preparation) but involves a less technically demanding and time-consuming clinical procedure and a less delicate restoration with a reduced risk of accidental breakage and post-bonding crack formation. The technique presented in this case report bridges the gap between a direct and indirect technique for diastema restoration and introduces a new treatment option to close anterior spacing with a highly esthetic sectional veneer in a predictable and timely manner.
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•Multifunctional superhydrophobic wood is obtained by a facile and effective method.•The durability of superhydrophobic coatings is highly improved by using of dopamine.•Resistance to ...chemical and mechanical damages are obtained in Cu coatings.•Antibacterial activities of wood samples are studied by bacteriostatic ring method.
Wood veneer had been widely used in interior decoration or fitment, but its application was still limited due to deformation after absorbing water and bacterial erosion. In this paper, a Cu coating owned superhydrophobic and antibacterial capabilities on wood veneer was fabricated by a facile and valid method. The wood veneer with superhydrophobic and antibacterial properties was prepared by self-polymerization of dopamine, chemical deposition of Cu nanoparticles, and hydrophobic modification using fluorosilane. The water contact angle and sliding angle of obtained Cu coating reached 155.7° and 4°, respectively. Meanwhile, the as-prepared coating showed resistance to acid or base solutions with different pH values, different temperatures aging and mechanical damages, and also displayed a good self-cleaning ability. In addition, the modified wood exhibited outstanding antibacterial activities towards Escherichia coli and Staphylococcus aureus. This work supplied a novel way to endow the superhydrophobic and antibacterial properties on wood veneer, and promote its multifunction application.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Frontal darkened teeth have shown to be one of the most challenging treatments for esthetic dentistry in recent years. This case report, along with a 30-month follow-up, describes the application of ...a partial ceramic veneer, restricted to the mid-cervical third region, made in the upper left central incisor darkened by trauma. The procedure consisted of maintenance of the entire incisal face, as well as esthetic and morphological rehabilitation of the smile line with veneers and ultra-thin partial ceramic veneers. The planning process was thoroughly elaborated by photographs, study models, a virtual smile designed, diagnostic waxing, and reproduction in the patient's mouth through mock-up. Following, dental home bleaching, esthetic gingival contouring, and minimally invasive tooth preparation were performed. Two types of glass ceramics (lithium disilicate and feldspathic) were used in different regions due to the peculiar characteristics of resistance, finishing, and polishing. According to the present case report, preparing a cervical partial ceramic veneer is an innovative, viable, and safe approach to maintaining the incisal portion of the tooth preserved and setting a detailed tooth morphology/color. The application of partial ceramic veneer provides incisal edge preservation and simplifies the reproduction of the adjacent tooth characteristics, avoiding multiple esthetic appointments.
The purpose of this in vitro study was to evaluate the influence of thermodynamic loading on the durability and fracture resistance behavior of occlusal veneers fabricated from different biomedical ...dental CAD/CAM materials.
The occlusal surfaces of 64 extracted premolars were prepared in the enamel layer and restored with occlusal veneers with a fissure/cusp thickness of 0.5/0.8mm made from four different dental CAD/CAM materials: group LD lithium disilicate (e.max CAD), group LS zirconia-reinforced lithium silicate (Vita Suprinity), group PI polymer-infiltrated ceramic (Vita Enamic), and group PM polymethylmethacrylate PMMA (Telio CAD). The prepared teeth were etched with phosphoric acid. The occlusal veneers were then bonded using an adhesive luting system (Multilink Primer A/B and Multilink Automix luting resin). Half of the specimens were subjected to thermodynamic loading in a chewing simulator (1.2 million cycles at 98N). All specimens were quasi-statically loaded until fracture. The statistical analysis was made using the t-test and one-way ANOVA followed by the Tukey HSD test (α = 0.05).
All aged specimens survived the thermodynamic loading. Thermodynamic loading significantly raised the fracture resistance in groups LS, PI, and PM (P < 0.03). Occlusal veneers made from lithium disilicate and zirconia-reinforced lithium silicate recorded higher fracture resistance than those made from polymer-infiltrated ceramic and PMMA resin.
All tested dental CAD/CAM biomaterials exhibited a fracture resistance considerably exceeding the average occlusal force in the posterior dentition. Therefore, they might present a viable long-term treatment for restoring the occlusal surfaces of posterior teeth.
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