• Journal of the Korean Wood Science and Technology
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• v.24 no.1
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• pp.34-47
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• 1996

Veneers of two nominal thicknesses, 1.5 and 2.5mm, were rotary peeled from Japanese larch (Larix leptolepis). Dahurian larch (Larix gmelinei) and Radiata pine (Pinus radiata) bolts unheated and heated in the water vat temperature of $66^{\circ}C$ by rising a final temperature at 10cm core of $60^{\circ}C$ to remain core diameter of 11.4cm. 1.5 and 2.5mm thick veneer cut from the heated Japanese larch were significantly thinner than those of the unheated bolt and 2.5mm thick veneer cut from the heated Dahurian larch were significantly thicker than that of the unheated bolt. 1.5mm thick Dahurian larch veneer and 1.5 and 2.5mm thick Radiata pine veneers showed insignificant difference between the unheated and heated bolts, respectively. Check distance on the loose side of 1.5mm thick veneer cut from the heated Radiata pine was significantly wider than that of the unheated bolt. However check distances on the loose side of 1.5 and 2.5mm thick Japanese larch and Dahurian larch veneers and 2.5mm thick Radiata pine veneers showed insignificant difference between the unheated and heated bolts. Also the depth of check on the loose side of three species showed insignificantly difference between the unheated and heated bolts. Arithmatic mean deviation($R_a$) and maximum height($R_{max}$) of the profile on the loose side of dried veneer by preheating the bolt compared with unheated bolts were different among apecies and between veneer thickness. The preheating treatment slightly affected qualities of these thin veneers such as 1.5 and 2.5mm. The yield of 2.5mm thick veneer from the heated radiata pine was significantly higher than that of the unheated bolt. However the yield of 2.5mm thick veneer for other two species and 1.5mm thick veneer for three species showed insignificant difference between the unheated and heated bolts. The yield of 2.5mm thick veneer for three species were higher than those of 1.5mm thick veneer. The average yields of green veneer of Japanese larch. Dahurian larch and Radiata pine were 57.1, 55.1 and 54.0 percent, respectively. Variables such as initial MC. drying time and veneer thickness had strong effect for Japanese larch veneer, less effect for Radiata pine veneer and nuch less effect on final MC for Dahurian larch veneer in jet drying. Correlation between the current MC and the drying time of Dahurian larch with low variation of initial MC was higher than those of Japanese larch and Radiata pine veneer with high variation of initial MC in high temperature drying. Thickness shrinkages of 2.5mm thick veneer for Japanese larch and Radiata pine were higher than those of 1.5mm thick veneers, but shrinkages of Dahurian larch veneer were similar between two nominal veneer thicknesses.

• Journal of the Korean Wood Science and Technology
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• v.33 no.4 s.132
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• pp.23-29
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• 2005

The fancy veneer flooring board is high value-added wooden material. The classification of the flooring boards by the observation with the naked eye causes color difference among fancy veneers. It turned out that this inaccuracy of color difference among fancy veneers increased in case of the identification by metamerism or the flooring construction. Therefore, this study was performed to classify fancy veneers produced from 3 species such as Tilia sp., Betula sp., and Acer sp. which were identified with the naked eye by Light and Dark grade, by using CIELAB. In addition, each specie's threshold on CIERGB was investigated and a range of hue, saturation and intensity by an application of HSI color model were studied. Intensity of the HIS color model could be the best value to be used when color, saturation and intensity of the HSI color model were used for the classification of the flooring board's color. In addition, it seemed that color range of all three criteria lied between $45^{\circ}$ and $55^{\circ}$. In the case of identification by threshold of RGB element, considering only specific color element value is unlikely to lead to accurate classification of fancy veneers of flooring board.

• The Journal of Korean Academy of Prosthodontics
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• v.57 no.3
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• pp.263-270
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• 2019

Current trends in restorative dentistry focus on improving the esthetics and keeping the sound dental tissues as long as possible. The aims of this case report were to describe the successful outcome of cubic-phase zirconia laminate veneers for a patient with isolated microdontia by using a digital workflow, and to describe their clinical implications. A 15-year-old female who had isolated microdontia in combination with spacing visited Ajou University Dental Hospital for esthetic treatment. In this case, 6 maxillary anterior teeth were restored with cubic-phase zirconia laminate veneers without tooth structure removal by using a digital impression, computer-aided design (CAD) software, and computer-aided manufacturing (CAM) procedures. At 6-month follow-up, no distinct mechanical and biological complications were detected and the prostheses exhibited satisfactory esthetics and functions. Due to its favorable tissue responses and enhanced translucency, cubic-phase zirconia can be a suitable strategy for a noninvasive esthetic approach.

• Applied Chemistry for Engineering
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• v.18 no.3
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• pp.251-254
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• 2007

Veneer plate was painted by the treatment with ammonium salts such as ammonium chloride (AMCR), ammonium sulfate (AMSF), monoammonium phosphate (MAPP), and diammonium phosphate (DAPP) at room temperature. The flame retardancy of painted veneer plate was investigated. The painted veneer plate shows an increased $CO/CO_2$ over virgin veneer and it was supposed to affect the toxicity to different extents. But when the ammonium salts were used as the retardant for veneer, the flame retardancy was improved due to the painted ammonium salts in the veneers. Also, the veneer plates with ammonium sulfate and ammonium chloride showed both the lower total smoke release (TSR) and lower total smoke production (TSP) than that of virgin veneer.

• Imaging Science in Dentistry
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• v.49 no.2
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• pp.171-176
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• 2019

The available methods for veneer evaluation are limited to clinical and radiographic examinations, which may not allow the appropriate identification of failure. In this report, we demonstrate the use of optical coherence tomography (OCT) as a noninvasive diagnostic and follow-up method to evaluate gingival recovery and the adhesive interface in aesthetic oral rehabilitation involving periodontal plastic surgery and ceramic laminate veneers. OCT was efficient for evaluating both soft and hard tissues, as well as the quality of the adhesive interface. In conclusion, OCT was found to be a promising approach for the professional evaluation of aesthetic oral rehabilitation, as it was capable of generating images that enabled the analysis of gingival recovery and the adhesive interface.

• Journal of the Korean Wood Science and Technology
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• v.39 no.4
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• pp.344-350
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• 2011

In this study, LVLs of radiata pine were fabricated with non-preservative treated veneers, CuAz treated veneers, and ACQ treated veneers, using aqueous vinyl urethane adhesive and phenol modified resorcinol resin adhesive. Then density gradient, bonding strength, bending properties and decay resistance of LVLs were evaluated. As results, the cone-shaped and higher density gradient pattern was found in layer close to glueline. After cyclic water boiled test, the LVL bonded with aqueous vinyl urethane resin adhesive was delaminated in all layers or partly delaminated including check, chasm in glueline layer. In the case of LVL bonded with phenol modified resorcinol resin adhesive, despite slight cupping due to great glueline stress and vertical check between glueline layers, it was observed that the bonding strength to delamination was higher, owing to most absence of delamination through overall glueline. On the other hand, in the decay test, mass loss by brown rot fungi was greater than white rot fungi in LVL bonded with aqueous vinyl urethane resin adhesive. However, in LVL bonded with phenol modified resorcinol resin adhesive, the mass loss by brown rot fungi was slight and non-preservative treated LVL was low. The mass loss of preservative-treated LVL was 0 (zero), showing the high decay resistance effect.

• Journal of the Korean Wood Science and Technology
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• v.4 no.1
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• pp.38-47
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• 1976

This study was carried out to exploit and utilize American sycamore (Platanus occidentalis) and poplar grown in Korea as veneer species for plywood manufacture. At this study to save the imported lauan logs and dollars, the effects affecting to the properties of plywood constructed by sycamore, poplar and lauan veneers were studied. Important items dealt with this study were dry and wet shear strength, moisture content, and specific gravities By the results and discussion it may be summarized as followings. 1) Sycamore core lauan plywood (A-II type) was shown best dry shear strength, and the next were all lauan veneer plywood (A-I type), poplar core lauan plywood (B-I type), lauan core sycamore plywood (A-III type) in order. There are no differences between dry shear strength of A-II type and A-I type, A-II type and B-I type plywood. 2) Wet shear strength showed the same order with dry shear strength. A-II type plywood showed best wet shear strength and it showed more difference than other plwoods. A-I type, B-I type and A-III type plywood were all very good without significant difference in wet shear strength. 3) B-I type plywood showed highest moisture content of all type plywood and the next were all sycamore(A-IV type) all poplar plywood (B-III type), A-III type, B-II type, A-II type pllywood in order. Generally high moisture content showed when two or three veneers were same species in the three layer plywood. 4) A-III type plywood showed highest specific gravity of all and the next was A-IV type plywood without a difference to A-I type plywood on the whole. plywoods constructed by lauan and sycamore were shown high specific gravities and the next was lauan, sycamore and poplar, lauan and poplar. It seemed to be that connected wi th the specific gravity of veneer itself in different species. 5) The plywood manufactured by extension of potato flour is not only superior but also profitable in the price aspect than the plywood manufactured by extension of wheat flour.

• Journal of the Korean Wood Science and Technology
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• v.27 no.3
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• pp.39-50
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• 1999

This research was carried out to investigate the development of fire-retardancy treatment technology and performance evaluation of fire-retardant treated plywoods. Radiata pine, keruing, dillenia, calophyllum and terminalia veneers were treated by normal(conventional) pressure soak(NPS) and vacuum-pressure-soak(VPS) using 20% water solution of diammonium phosphate. Then, 4.8mm thick, 3ply plywoods were fabricated with combination of fire-retardant treated, untreated or water-immersion types and several composition types of radiata pine and keruing veneers, i,e. the uniform and the mixed types in species composition, and the homogenious and the alternate layer types in veneer treatment. In composed species, the retention and the treatment effects of fire-retardant chemicals III radiata pine was still greater than those of keruing. The effect of VPS treatment was larger than that of NPS treatment, however, adhesive bonding strength and bending strength of plywoods treated by these two methods were not necessarily lowered, compared to those of untreated plywood. And also, fire endurance performance of the urea melamine resin-bonded plywood was greater than that of the phenol resin-bonded plywood. In result, the appropriate combination in veneer species and layer as well as alternate fire-retardant treatments would be more efficiently available in service.

• Journal of the Korean Academy of Esthetic Dentistry
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• v.1 no.1
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• pp.50-57
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• 1992

Intrinsic discoloration of permanent anterior teeth is a continuing esthetic problem. Tetracycline ingested during amelogenesis has long been recognized as predisposing factor in intrinsic staining. Methods for restoring original tooth color have included (1) complete PFM crown coverage (2) porcelain laminate veneers (3) direct bonding of composite resin, and (4) bleaching. In the case of tetracycline-stained upper anterior teeth, We authors, obtained the satisfactory results by means of gingivectomy, preliminary bleaching and porcelain laminate veneer restoration.

• Proceedings of the KACD Conference
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• 2001.05a
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• pp.233-234
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• 2001

IPS Empress 2 veneer system was advantageous when veneers required bulk or were under load from function and parafunction activity. Practitioners should consider its use for situations that require a stronger veneer material.