• Journal of Dental Rehabilitation and Applied Science
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• v.29 no.1
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• pp.37-44
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• 2013

Sodium hypochlorite and ethylene diamine tetra acetic acid are substances usually used during endodontic treatment. Several studies found that the bonding was negated with certain irrigants and some of the used irrigants have demineralizing and chealating effects, so it was advocated to omit the etching step in etch and rinse adhesive systems. The purpose of this in vitro study was to evaluate the influence of NaOCl & EDTA on the bonding strength of ethanol wet bonding. Thirty human molars were selected and mesiodistally sectioned into halves, thus providing sixty specimens. The specimens were randomly assigned to 4 groups(n=15) according to the irrigant regimen used : (1) irrigated with distilled water for 10min (control); (2) irrigated with 5.25% NaOCl(10min), flushed with 5.25% NaOCl(1min) (3) irrigated with 5.25% NaOCl, flushed with 17% EDTA (4) irrigated with 5.25% NaOCl, flushed with 17% EDTA. Each group was acid-etched with 37% phosphoric acid(except group 4) and had their dentin surfaces dehydrated with ethanol solutions : 50%, 70%, 80%, 95%, 3x100%, 30s for each application. After dehydration, a primer( 50% all bond 3 resin + 50% ethanol) was used, followed by the adhesive(ALL-BOND 3 RESIN) application. Resin composite build-ups were then prepared using an incremental technique. Specimens were sectioned into beams and submitted to a tensile load using a Micro Tensile Tester(Bisco Inc.). The data were statistically analyzed using one-way ANOVA and Tukey HSD at p<0.5 level. There was no significant difference on G1(control) and G2(irrigated with NaOCl only ). (p>0.05). G3(flushed with EDTA) showed significantly high tensile bonding strength compared to the G2 (p<0.05). G4( treated with EDTA but no acid-etching) was significantly lower value than G3. (p<0.05) Although there was no significant difference, 5.25% NaOCl seemed to have an adverse effect on the bonding strength of ethanol wet bonding. The flushing with EDTA after NaOCl irrigation prevents the decrease of bonding strength. The use of 17% EDTA as a final flush can enhance the bonding strength but EDTA flushing can't substitute for a acid-etching.

• The korean journal of orthodontics
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• v.29 no.4 s.75
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• pp.445-456
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• 1999

As a result of increased education and communication, the field of orthodontics has recently been expanded to include a greater number of adult treatment procedures. With this increased demand for adult orthodontic treatment, a problem that frequently arises is the placement of appliances on teeth restored with porcelain. But conventional acid-etching is ineffective in the preparation of porcelain surface for mechanical retention of orthodontic attachments. Also, it is possible to damage on porcelain. The purpose of this study was to evaluate the effect of composite bonding materials and the porcelain surface treatment methods on shear bond strength, and to observe the porcelain fracture rates. To accomplish this purpose, this study was carried out with feldsphatic porcelain, Ceram II. Porcelain surface treatment methods were divided into intact glazed porcelain which had not treatment and surface roughening. Surface roughening by etching with Hydroluoric acid(HF), sandblasting with Microetcher II and compound treatment with etching and sandblasting. Bonding materials were Ortho-two and Transbond. All porcelain specimens were applicated with porcelain primer. 1. In comparision according to porcelain surface treatment, surface roughening groups by HF etching and sandblasting had higher shear bond than intact group. No significant difference was found in Transbond group. 2. Ortho-two group had the higher shear bond strength than that of Transbond group in B:.u etching and sandblasting. 3. E(Transbond. Intact)group had the lowest shear bond strength in all experimental group. The bond strength was higher than clinically successful bond strength. 4. Non-treated group had very higher porcelain rates than treated group. 5. This study indicates that porcelain surface-roughening may not be necessary to attachment of orthodontic brackets to porcelain surfaces.

• Restorative Dentistry and Endodontics
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• v.21 no.1
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• pp.242-253
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• 1996

Penetration degree of several dyes into dentinal tubules in vivo was compared with in vitro, and experimental sensitivity of those dyes was investigated in 64 canines of 16 cats. Dentin 1mm below cusp tip was exposed by cross-sectioning with diamond disc. Pulp of 32 canines were extirpated through cervical cavities. In the presence of smear layer or after add-etching with 37% phosphoric acid to the exposed dentin surface, acrylic collar and resin cap was attached to keep dyes. 52 mmol/$\ell$ Evans' blue, 2% Methylene blue, 10 % Silver nitrate and 5% Fluorescene were then applicated on each 4 canines respectively for 30 minutes. After rinsing, the canines were ground-sectioned longitudinally and linear dye penetration was measured under microscope. The results obtained were as follows ; 1. Evans' blue and Methylene blue penetrated significantly(P<0.05) more in vitro than in vivo only in the cases that exposed dentin surfaces were not etched with acid. 2. Silver nitrate penetrated significantly(P<0.05) more in vitro than in vivo in both cases that exposed dentin surfaces remained intact and were etched with acid. 3. The penetration degree of Fluorescene did not show statistical significance between in vivo and in vitro or in acid-etched and in not acid-etched cases.

• Textile Coloration and Finishing
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• v.1 no.1
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• pp.7-18
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• 1989

The distinguishing characteristic of the glow discharge is that chemical reaction induced by partially ionized gases are limited only to the substrate surface. Most studies have been done on the plasma etching and polymerization. The graft polymerization in vapour phase by cold plasma has been rarely investigated. In this study the system of tub3ar reaction chamber with capacitively coupled electrode of alternative current of 60 Hz was employed for the graft polymerization. The graft polymerization of Acylic Acid(AA) onto the poly (ethylene terephthalate) (PET) was carried out by treatment of PET film and fabric by cold plasma (glow discharge of argon gas), followed by the supply of AA vapour. The graft yield was about 1 wt%. The surface property was determined by contact angle, the surface tension was evaluated by zisman’s plot and equation of surface tension mesurement. The results were as follows: 1. In order to obtain lower contact angle, it was effective to avoid the vicinity of electrodes for a setting position of substrate. 2. Contact angle affected on the monomer pressure and its duration of exposure to the acid vapour. 3. Polymer radical formation was influenced by the changes of the value of current density and plasma treatment time. 4. Total surface tension of plasma grafted PET film increased. With an increase in the carboxylic acid content, the dispersion force decreased, while, the polar force and hydrogen bonding force increased. 5. The contact angle decreased from $75^\circ$ to around $30^\circ$ by plasma grafting. There was no ageing effect on the contact angle after 4 months.

• Archives of Plastic Surgery
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• v.34 no.4
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• pp.471-477
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• 2007

Purpose: Hydrofluoric acid(HF) is one of the most dangerous mineral acids with dissociated fluoride ions. As hydrofluoric acid is present in various household products(such as rust removers), a large population of industrials is at the risk of HF exposure. It is a very strong organic acid, used widely in glass etching, metal washing, and in the semiconductor industry. Even when using adequate safety measures, lack of care on the user's part results in chemical burn by HF. Symptoms caused by HF-induced chemical burns shows delayed manifestations resulting in a loss of proper treatment opportunities. We therefore reviewed 20 cases of HF-induced chemical burns and treatment principle. Methods: The objects of this study were 19 male patients and 1 female treated from March 2004 to March 2006. There were 19 cases of injury on digits and 1 on the wrist area. There were 15 cases of immediate treatment after sustaining HF-induced burns, and 5 cases of delayed treatment. As a principle, in the emergency treatment, partial or complete removal of the nail along with copious washing with normal saline was done, depending on the degree of HF invasion of the distal digital extremities. Results: The 15 cases who came to the hospital immediately after the injury were healed completely without sequelae, and those who delayed their treatment needed secondary surgical measures, due to the severity of inflammation and necrosis of the digital tissues. Conclusion: As the industrial sector develops, the use of HF is increasing more and more, leading to increase in incidences of HF-induced chemical burns. When treating chemical burns caused by HF, washing by copious amounts of normal saline, along with early removal of the nails, rather than calcium gluconate, seems to be a available method for preserving the shape and function of the digits and the nail. The education of patients regarding this subject should be empathized accordingly.

• Journal of the Korean Society of Safety
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• v.35 no.6
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• pp.85-92
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• 2020

Wet Scrubber reacts the incoming pollutant gas with cleaning water (water + absorbent) to absorb pollutants and release the clean air to the atmosphere. Wet scrubbers and packed tower scrubbers using this principle are widely used in businesses that emit acid gases. In particular, in the etching process using hydrochloric acid (HCl), alkaline washing water (NaOH) having a pH of about 8 to 11 is used to absorb a large amount of acid gas. However, These salts are attached to the injection nozzle (nozzle), filling material (packing), and the demister (Demister), causing air pollution, human damage, and inoperability due to clogging and acid gas discharge. Therefore, In this study, an improvement plan was proposed to manage the washing water with pH 3~4 acidic washing water. The test method takes samples from the Wet Scrubber flue measurement laboratory twice a month for 1 year. Hydrogen chloride (HCl) concentration (ppm) was measured, and nozzle clogging and scale conditions were measured, compared, and analyzed through a differential pressure gauge and a pressure gauge. As a result of the check, it was visually confirmed that the scale was reduced to 50% or less in the spray nozzle, filler, and demister. In addition, the emission limit of hydrogen chloride in accordance with the Enforcement Regulation of the Air Quality Conservation Act [Annex 8] met 3 ppm or less. Therefore, even if the washing water is operated in an acidic pH range of 3 to 4, it is expected to reduce air pollution and human damage due to clogging of internal parts, and it is expected to reduce maintenance costs such as regular cleaning or replacement of parts.

• The Journal of Korean Academy of Prosthodontics
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• v.57 no.4
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• pp.335-341
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• 2019

Purpose: Chemically strong-acids (HF and $HCl/H_2SO_4$) dual etching implant surfaces have higher strengths of osseointegration than machined implant surfaces. However, the dual acid treatment deteriorates the physical properties of the titanium by weakening the fatigue resistance of the implant and causing microcracks. The removal torque comparison between the dual-acid etched (hydrochloric acid, sulfuric acid, HS) and single-acid etched implants (hydrochloric acid, H) could reveal the efficiency of implant surface acid treatment. Materials and methods: Nine $3.75{\times}4mm$ dual-acid etched SLA implants and nine single-acid etched SLA implants were inserted into New Zealand rabbit tibias. After 10 days, removal torque, roughness, and wetting angle were measured. Results: Mean removal torque values were as follows: Mean removal torque were 9.94 Ncm for HS group and 9.96 Ncm for H group (P=.995). Mean surface roughness value were $0.93{\mu}m$ for HS group and $0.84{\mu}m$ for H group (P=.170). Root mean square roughness (RSq) values were $1.21{\mu}m$ for HS group and $1.08{\mu}m$ for H group (P=.294), and mean wetting angle values were $99^{\circ}$ for HS group and $98^{\circ}$ for H group (P=.829). Statistical analysis showed no significant difference between the removal torques, roughness, or wetting angles of the two groups. Conclusion: In this experiment, we found no significant difference in removal torque, roughness, or wetting angle between dual-acid etched and single-acid etched implants.

• The korean journal of orthodontics
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• v.41 no.4
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• pp.268-279
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• 2011

Objective: The purpose of this study was to compare self-drilling orthodontic mini-implants of different surfaces, namely, machined (untreated), etched (acid-etched), RBM (treated with resorbable blasting media) and hybrid (RBM + machined), with respect to the following criteria: physical appearance of the surface, measurement of surface roughness, and insertion pattern. Methods: Self-drilling orthodontic mini-implants (Osstem implant, Seoul, Korea) with the abovementioned surfaces were obtained. Surface roughness was measured by using a scanning electron microscope and surface-roughness-testing machine, and torque patterns and vertical loadings were measured during continuous insertion of mini-implants into artificial bone (polyurethane foam) by using a torque tester of the driving-motor type (speed, 12 rpm). Results: The mini-implants with the RBM, hybrid, and acid-etched surfaces had slightly increased maximum insertion torque at the final stage ($p$ < 0.05). Implants with the RBM surface had the highest vertical load for insertion ($p$ < 0.05). Testing for surface roughness revealed that the implants with the RBM and hybrid surfaces had higher Ra values than the others ($p$ < 0.05). Scanning electron microscopy showed that the implants with the RBM surface had the roughest surface. Conclusions: Surface-treated, self-drilling orthodontic mini-implants may be clinically acceptable, if controlled appropriately.

• Journal of Periodontal and Implant Science
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• v.30 no.1
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• pp.145-157
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• 2000

Cytotoxic substances in dental calculus and root cementum of periodontally diseased teeth inhibit new attachment and regeneration. The purpose of scaling and root planing is to remove pathologic structures harboring these cytotoxic substances in order to create a biologically acceptable root surface. However, these procedures inevitably leave a non-biocompatible smear layer. Conventionally, the smear layer has been removed with low pH etching agents such as citric acid, phosphoric acid and tetracycline hydrochloride(TC). Lately, a supersaturated neutral pH etching solution of ethylene diamine tetraacetic acid(EDTA) has been found to be as effective as low pH etchants with respect to smear removal and to be superior in exposing root surfaceassociated collagen. The aim of the present study was to determine the effect of root surface treatment using EDTA on the initial attachment of human gingival fibroblasts. 27 human teeth, extracted due to severe periodontitis, were cut into dentin slices after root planing. The specimens were divided into TC group(treated with $50㎎/m{\ell}$ tetracycline-HCl, pH 1.52), EDTA group(treated with 17% EDTA, pH 7.4), and non-treated control group. After sterilization, 5th subcultured human gingival fibroblasts were seeded in each culture well containing a prepared root slice and incubated for 15 min., 60 min., and 4 hours in 5% $CO_2$ incubator at $37^{\circ}C$. At each incubation time, the number of attached fibroblasts were counted on the microphotographs taken at a magnification of x100. The difference of the number of attached cells between groups was statistically analyzed by the ANOVA followed by Duncan test in SPSS/PC＋programs. The results were as follows : 1. After incubation for 15 min, the attached cells were significantly more in EDTA group and TC group than non-treated control group(p<0.05), but there was no significance in the difference between EDTA group and TC group(p>0.1). 2. After incubation for 60 min and 4 hours, there was no significant difference in the number of attached cells between all groups(p>0.1). 3. In both EDTA group and TC group, there was no significant difference in the number of attached cells between different incubation(p>0.1). But in control group, the number of attached cells was significantly increased after incubation for 60 min, compared with incubation for 15 min(p<0.05). The above results suggest that root surface treatment using EDTA could enhance the initial attachment of gingival fibroblasts to root surface as effective as tetracycline-HCl.

• Journal of Dental Rehabilitation and Applied Science
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• v.37 no.4
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• pp.209-216
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• 2021

Purpose: The purpose of this study is to compare the shear bond strength of resin cement for orthodontic brackets without applying an adhesive primer, to the case of applying an adhesive primer. Materials and Methods: The specimens were divided into three experimental groups, Transbond XT, GC Ortho Connect and Orthomite LC, and the enamel surface was divided into two sections, one with 37% phosphoric acid and the other with 37% phosphoric acid and an adhesive primer or universal adhesive. Each of three types of cement was applied to orthodontic bracket, and after bonding, the shear bond strength was measured. Results: Transbond XT and Orthomite LC significantly increased shear bond strength when orthodontic brackets were bonded after applying an adhesive primer and universal adhesive, respectively. Conclusion: It is expected that application of an adhesive primer or universal adhesive after acid etching will improve shear bond strength of orthodontic brackets in Transbond XT and Orthomite LC.