• Restorative Dentistry and Endodontics
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• v.40 no.1
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• pp.68-74
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• 2015

Objectives: This study examined the effects of additional acid etching on the dentin bond strength of one-step self-etch adhesives with different compositions and pH. The effect of ethanol wetting on etched dentin bond strength of self-etch adhesives was also evaluated. Materials and Methods: Forty-two human permanent molars were classified into 21 groups according to the adhesive types (Clearfil SE Bond [SE, control]; G-aenial Bond [GB]; Xeno V [XV]; Beauti Bond [BB]; Adper Easy Bond [AE]; Single Bond Universal [SU]; All Bond Universal [AU]), and the dentin conditioning methods. Composite resins were placed on the dentin surfaces, and the teeth were sectioned. The microtensile bond strength was measured, and the failure mode of the fractured specimens was examined. The data were analyzed statistically using two-way ANOVA and Duncan's post hoc test. Results: In GB, XV and SE ($pH{\leq}2$), the bond strength was decreased significantly when the dentin was etched (p < 0.05). In BB, AE and SU (pH 2.4 - 2.7), additional etching did not affect the bond strength (p > 0.05). In AU (pH = 3.2), additional etching increased the bond strength significantly (p < 0.05). When adhesives were applied to the acid etched dentin with ethanol-wet bonding, the bond strength was significantly higher than that of the no ethanol-wet bonding groups, and the incidence of cohesive failure was increased. Conclusions: The effect of additional acid etching on the dentin bond strength was influenced by the pH of one-step self-etch adhesives. Ethanol wetting on etched dentin could create a stronger bonding performance of one-step self-etch adhesives for acid etched dentin.

• Korean Journal of Dental Materials
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• v.45 no.4
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• pp.301-310
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• 2018

The purpose of this study is to evaluate the compatibility of universal adhesives with two dual-cured resin cements. Eighty human molars were divided into eight groups. Tooth was embedded in self-curing acrylic resin and sectioned horizontally to exposure dentine surface. After polishing with 600-grit SiC paper, adhesives were applied. All-Bond Universal (Bisco), G-premio bond (GC), Scotch-bond universal (3M ESPE), Scotch-bond Multipurpose (3M ESPE) were used in this study. Calibra (Dentsply) as a conventional dual-curing resin cement and RelyX Ultimate (3M ESPE) as an amine free resin cement were used. The adhesives and the cements were applied according to the manufacturer's instructions. Final specimens were cylinder (diameter 2mm, height 3mm) shape. After storing in distilled water at $37^{\circ}C$ for 7 days the shear bond strength (SBS) test was performed. There was no significant difference in shear bond strength between the adhesives when RelyX Ultimate was used (p>0.05). However, when Calibra used with Scotch-bond Multipurpose and All-Bond Universal were used, statistically higher SBS was observed, as compared to the groups which Calibra cements with G-premio bond and Scotch-bond universal adhesive (p<0.05) were used. Within the limitations of this study, RelyX Ultimate resin cement was compatible with universal adhesives of various pH. All-Bond Universal adhesive was compatible with a resin cement containing the tertiary amine.

• Journal of the Korean Wood Science and Technology
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• v.25 no.1
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• pp.37-41
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• 1997

Hot-water soluble extracts were prepared from medium-sized barks of Siberian larch (Larix gmelineii). The extracts were fractionated by ultrafiltration method for producing uniform quality of adhesives. Molecular weight distribution of the extracts was ranged of 100 to 300.000. pH of the extracts affected amounts of flux, and the range of pH 6~pH 8 was proper for wood adhesives, because of easy concentration and fast gelation time. Removal of particles greater than $0.45{\mu}m$ from the extracts increased both filtration speed (flux) and yields of solids in the filtrates. In ultrafiltration process. operating pressure, filtrate temperature, and flow rate significantly increased with the increase of individual condition. Ultrafiltration using PM10 membrane was very effective to fractionate and concentrate the extracts. Removal of large particles greater than 0.45 m from the extracts increased filtration speed(flux) and yields of solids in the filtrates. A gelation time was accelerated with the increasing pH of the extracts and its concentration. The Stiasny precipitate(26%) from the filtrate obtained by PM 10 membrane was very lower than that(78%) of the retentates. This ultrafiltration method was efficient for obtaining high yield purified phenolic compounds.

• Journal of Conservation Science
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• v.37 no.3
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• pp.282-288
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• 2021

This basic research was conducted to support the development of woodcraft bio-adhesives using peach gum, which is the resin produced by peach trees. The synthesis conditions of these adhesives were optimized by performing 144 experiments. The application potential of peach gum adhesives was explored by comparing their properties with those of three natural adhesives and four synthetic adhesives. The best adhesive strength was obtained by dissolving the resin in 80 mL of distilled water containing 1.5 g NaOH, 1.65 g H₂O₂ ( pH 8.0-9.0), 0.5 g NaClO, and 0.5 g H₂BO₂. The adhesive strength, which showed minimal changes and excellent reversibility, was 125.39 kgf/cm². Ultraviolet radiation-mediated deterioration in strength in the absence of total aerobic bacteria was negligible (△E^*ab = 2.75). These data confirm the potential value of peach gum-based bio-adhesives for woodcraft as well as their utility as alternatives for natural and synthetic adhesives used for the manufacture and restoration of handicrafts and preservation of cultural assets.

• Restorative Dentistry and Endodontics
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• v.43 no.3
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• pp.29.1-29.13
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• 2018

Objectives: The aims of this study were to conduct a systematic review of the microtensile bond strength (${\mu}TBS$) of multi-mode adhesives to dentin and to perform a meta-analysis to assess the significance of differences in the ${\mu}TBS$ of one of the most commonly used universal adhesives (Scotchbond Universal, 3M ESPE) depending on whether the etch-and-rinse or self-etch mode was used. Materials and Methods: An electronic search was performed of MEDLINE/PubMed, ScienceDirect, and EBSCOhost. Laboratory studies that evaluated the ${\mu}TBS$ of multi-mode adhesives to dentin using either the etch-and-rinse or self-etch mode were selected. A meta-analysis was conducted of the reviewed studies to quantify the differences in the ${\mu}TBS$ of Scotchbond Universal adhesive. Results: Only 10 studies fulfilled the inclusion criteria for the systematic review. Extensive variation was found in the restorative materials, testing methodologies, and failure mode in the reviewed articles. Furthermore, variation was also observed in the dimensions of the microtensile testing beams. The meta-analysis showed no statistically significant difference between the etch-and-rinse and self-etch modes for Scotchbond Universal adhesive (p > 0.05). Conclusions: Multi-mode 'universal' adhesives can achieve substantial bonding to dentin, regardless of the used modes (either etch-and-rinse or self-etch).

• Journal of Adhesion and Interface
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• v.12 no.4
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• pp.125-132
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• 2011

As the enhancement of indoor air quality is increasingly compelling the use of natural materials without any emission, this study reports the preparation and performance of natural garlic adhesives for wallpaper. The natural garlic adhesives were successfully prepared by the extraction of the clove of raw garlic with water to isolate carbohydrates and proteins. Properties of the prepared garlic adhesives such as the non volatile solids content, viscosity, density, and pH were 62%, 2,789 mPa.s, $1.3g/cm^3$, and 6.6, respectively. The non-volatile solids content has a great impact on the adhesion performance of the prepared garlic adhesives, which was adequate about 60%. Bonding strength of prepared garlic adhesives was greater than the requirement of a Korean standard for wallpaper. In addition, the garlic adhesives showed antibacterial activity inheriting from the garlic. It is expected that the prepared garlic adhesives could be used as safe and natural adhesives without emitting any volatile organic compounds and formaldehyde gas.

• Journal of Conservation Science
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• v.35 no.6
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• pp.681-688
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• 2019

In this study, the characteristics of natural and synthetic adhesives used in woodcraft were evaluated. The pattern of deterioration of wood and adhesives according to changes in temperature and humidity were compared. For materials, one type of anlmal glue, three kinds of polyvinyl acetate adhesives, one type of epoxy adhesive and one type of zelkova wood were selected. Characteristics of physical and chemical characteristics, weather resistance and drying speed assessment were carried out. The adhesion characteristic evaluation showed that the adhesion strength of anlmal glue and one type of polyvinyl acetate adhesive were 6.54 N/㎟ and 7.01 N/㎟, pH meter of anlmal glue and polyvinyl acetate adhesives was pH 7.03 and pH 3.32-3.59 which were range of available as an adhesive. According to the test results of weather resistance, epoxy adhesives had the highest decreasing value in adhesion strength after deterioration. In the reversible test of the adhesive, it was found to be highly reversible in NaOH, a soluble solvent excluding epoxy, but attention is required when using the wood since it may show discoloration during processing.

• Journal of the Korean Wood Science and Technology
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• v.35 no.5
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• pp.67-75
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• 2007

As a part of abating the formaldehyde emission of urea-formaldehyde (UF) resin adhesive by lowering formaldehyde to urea (F/U) mole ratio, this study was conducted to investigate properties of UF resin adhesive with different F/U mole ratios. UF resin adhesives were synthesized at different F/U mole ratios of 1.6, 1.4, 1.2, and 1.0. Properties of UF resin adhesives measured were non-volatile solids content, pH level, viscosity, water tolerance, specific gravity, gel time and free formaldehyde content. In addition, a linear relationship between non-volatile solids content and sucrose concentration measured by a refractometer was established for a faster determination of the non-volatile solids content of UF resin. As F/U mole ratio was lowered, non-volatile solids content, pH, specific gravity, water tolerance, and gel time increased while free formaldehyde content and viscosity were decreased. These results suggested that the amount of free formaldehyde strongly affected the reactivity of UF resin. Lowering F/U mole ratio of UF resin as a way of abating formaldehyde emission consequently requires improving its reactivity.

• Journal of the Korean Wood Science and Technology
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• v.25 no.1
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• pp.23-27
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• 1997

Alkali-soluble extracts were prepared from barks of Japanese larch(Larix leptolepis). Siberian larch(Larix gmelineii) and Radiata pine(Pinus radiata) The effect of various factors, such as particle size, liquor ratio, extraction temperature, and reaction time, on the extracts yield was investigated. Particle sizes affected the alkali-soluble extracts; the finer the particle size, the higher extracts and extract efficiency. High temperature and high liquor ratio were more effective. In the range of 0.25% to 1% NaOH concentration, alkali extracts were increased with the increasing alkali concentration. However, extract yields were leveled off above 0.5% alkali concentration. Extractions with NaHCO3 were almost equivalent to those of NaOH extraction. 1% NaOH and 1% NaHCO3 resulted in the highest yields of alkaline extracts. Extracts from Japanese larch were lower than those from Siberian larch and Radiata pine barks. Siberian larch bark was the best raw material for tannin adhesives, because its extractive yield was higher than those of the other barks. Concerning pH of alkaline media during extraction, small increases of the extract yields were resulted at range of pH 7 to pH 9, while a large increases from pH 9.0 to pH 12. This phenomenon is attributed to higher alkalinity.

• Journal of Adhesion and Interface
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• v.4 no.3
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• pp.9-13
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• 2003

In this paper, the effects of crosslinking agent and pH controlling agent on adhesive properties and water solubility of water soluble acrylic pressure sensitive adhesives were studied by adding the crosslinking agents or pH controlling agents after the polymerization. the tack, cohesive strength, and peel strength were measured to evaluate adhesive properties. the turbidity was also measured to evaluate water solubility of pressure sensitive adhesives. When crosslinking agent was added less than 0.2 wt%, tack increased and cohesive strength and peel strength decreased with increasing concentration. When crossinking agent was added more than 0.2 wt%, the results were opposited. When pH controlling agent was added, tack and water solubility decreased and peel strength and cohesive strength increased with increasing concentration. the influence of pH controlling agents on adhesive properties and water solubility of pressure sensitive adhesive increased in the order of lithium hydroxide, potassium hydroxide and sodium hydroxide.