• 보존과학연구
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• s.21
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• pp.101-118
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• 2000

Stone cultural properties(pagoda, Buddhist statue etc.) is moved in original place for many reasons and restored after taking to pieces for structural safety. With the movement and restoration after taking to pieces, the cast iron is used for the sake of a fixation and horizontality. The stone cultural properties are spoiled the beauty and accelerated the weathering because of the corrosion product of cast iron. So we need to substitute for the improved property in all aspects. We are executed the corrosion test and inquired the property of material on the usable material for the shim of stone cultural properties. That is the Cast iron, Stainless steel, Titanium and Fiber Reinforced Plastics. In the result of the physical property and strength, the Stainless steel and Titanium was superior to the Cast iron. And the Stainless steel and Titanium was slower than the Cast iron in the corrosion velocity for the acid, salt and rain. If the shim is substitute the Stainless steel or Titanium for the Cast iron, the stone cultural properties are able to reduce the pollution of stone cultural properties by corrosion product and should not happen in the matter of stone pagoda.

• The Journal of Korean Academy of Prosthodontics
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• v.33 no.3
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• pp.569-583
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• 1995

Disinfection of dental impressions are necessary due to contamination with patient’s saliva and blood, which is a potential for cross-infection. The purpose of this study was to evaluate the effects of disinfection of four hydrophilic rubber impression materials with three disinfecting solutions, on the dimensional stability and surface hardness of improved stone casts. Three hydrophilic vinyl polysiloxane impression materials(Express, Reprosil, Exafine) and one polyether impression material(Impregum-F) were mixed according to the manufacturer’s directions and impressions were made on a ADA specification No. 19 stainless-steeldie. On removal of the impressions, each impression was immersed in one of the disinfectants(Banicide, Potadine, Clorox) for 10 minutes. After disinfection, type IV improved stone. casts were poured. On this cast, the linear dimension and surface hardness were measuredusing a Measurescope(Nikon, Japan) and a Barcol hardness tester(Barber, Colman Co U. S. A). The results were as follows : 1. The improved stone casts from disinfected Reprosil and Impregum-F impression material did not show dimensional changes(P>0.01). Those from disinfected Express and Exafine impression material showed dimensional changes(P<0.01). The amount of shrinkage was not clinically significant. 2. The improved stone casts from disinfected Express impression material did not exhibit changes in surface hardness(P>0.01), but those from disinfected Reprosil, Exafine, Imp regnum-F impression material showed changes in surface hardness(P<0.01). 3. The dimensinal stability and surface hardness of the improved stone casts were satisfactory using Banicide on Express, all disinfectants used in this study on Reprosil, Potadin and Clorox on Exafine, Banicide and Clorox on Impregum-F. According to these results, immersion disinfection of hydrophilic rubber impression mate rials did not adversely affect the resultant casts. Nevertheless compatibility tests of impression materials and disinfectants should be done when disinfecting impressions.

• The Journal of Advanced Prosthodontics
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• v.14 no.6
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• pp.379-387
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• 2022

PURPOSE. The aim of this study is to compare the casts obtained by using conventional techniques and liquid crystal display (LCD) three-dimensional (3D) print techniques in the All-on-4 treatment concept of the edentulous mandibular jaw. MATERIALS AND METHODS. In this study, a completely edentulous mandibular acrylic cast (typodont) with bone-level implants placed with the Allon-4 technique served as a reference cast. In this typodont, impressions were taken with the conventional technique and dental stone casts were obtained. In addition, after scanning the acrylic cast in a dental laboratory scanner and obtaining the Standard Tessellation Language (STL) data, 3D printed casts were manufactured with a 3D printing device based on the design. The stone and 3D printed casts were scanned in the laboratory scanner and STL data were obtained, and then the interimplant distances were measured using Geomagic Control X v2020 (3D Systems, Rock Hill, SC, USA) analysis software (n = 60). The obtained data were statistically evaluated with one-way analysis of variance (ANOVA) and Tukey's pairwise comparison tests. RESULTS. As a result of the one-way ANOVA test, it was determined that the stone casts, 3D printed casts, and reference cast values in all distance intervals conformed to the normal distribution and these values had a significant difference among them in all distance intervals. In Tukey pairwise comparison test, significant differences were found between casts at all distance intervals. In all analyses, the level of significance was determined as .05. CONCLUSION. 3D printed casts obtained with a 3D LCD printing device can be an alternative to stone casts when implants are placed in edentulous jaws. [J Adv Prosthodont 2022;14:379-87]

• Journal of the Korean Society of Radiology
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• v.83 no.1
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• pp.224-229
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• 2022

Biliary cast syndrome is an unusual complication in patients who have previously undergone liver transplantation. It occurs in approximately 5%-18% of such patients. Rare cases of biliary cast syndrome in patients without liver transplants have also been reported. The pathogenesis of biliary cast has not been clearly identified, although etiologic factors including post-transplant bile duct damage, ischemia, biliary infection, and presence of a post-operative biliary drainage tube have been proposed. Here we present a case of biliary cast that developed in a 49-year-old male who underwent a non-liver surgery after endoscopic and percutaneous management of common bile duct stone.

• The Journal of Korean Academy of Prosthodontics
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• v.43 no.4
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• pp.453-465
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• 2005

Purpose: This study was performed to measure the accuracy of adjustable dental impression trays by a scanning laser three-dimensional digitizer. Materials and methods: The metal stock, individual, and adjustable stock trays were used for 60 stone casts(10 casts each) duplicated a resin master model of mandible and maxilla. The type IV dental stone was poured in a vinyl polysiloxane impressions and allowed to set for one hour. The master model and the duplicated casts were digitized using an optical digitizer. The distance between the reference points were measured and analyzed on the graphic image of 3-D graphic software(CATIA version 5.0). The statistical significance of the differences between the groups was determined by a two-way ANOVA. Results : There were no significant differences between the accuracies of the adjustable stock tray and the master model except only anterior arch width on the upper arch and the diagonal arch length and arch length on one side of the lower arch. Conclusion: The adjustable stock trays showed clinically acceptable accuracies of the study cast produced by them.

• The Journal of Korean Academy of Prosthodontics
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• v.39 no.5
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• pp.492-501
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• 2001

The use of alginate impression materials today is prevalent because of its efficiency and simplicity in clinical settings. Unfortunately, the simplicity of the procedure tends to lull the dentist into a sense of well-being, and lead him into using careless or sloppy technique. Alginate impression materials are used to fabricate diagnostic and preliminary casts, and the final cast. Incorrect use of this material is known to affect the accuracy of the final prosthesis. The purpose of this study was to compare the effect of different mixing methods of alginate impression material and tray adhesive on the accuracy of the stone cast produced by each method. A total of 30 stone casts were produced by using 3 different types of mixing methods (10 stone cast for each mixing method, respectively). The first method utilized an automatic-mixing machine to mix alginate while the second method was carried out manually, strictly following manufacturer's instructions. The third method also involved manual mixing, but did not follow the manufacturer's instructions and was done in a random fashion. Also, 20 additional stone casts were produced by using alginate with or without tray adhesives were included in the study to evaluate effects of tray adhesives on the accuracy of alginate impression. 10 stone casts were produced by adding tray adhesives to the interior surface of the impression tray prior to taking the impression. The other 10 excluded this step. A total of 50 stone casts were analyzed by the three-dimensional measuring machine to measure and compare the dimensional changes of the impression material of each group. The results are as follows. 1. No significant difference was found between the automatic mixing group and the manually-mixing group(p>0.05). 2. For the group that followed manufacturer's instructions, less dimensional changes were record ed than the group that didn't in measuring distanced 4(p<0.05). 3. The group that used tray adhesives showed less dimensional changes(p<0.05). The findings revealed that mechanical methods of mixing alginate impression materials had little influence on dimensional changes. However, it is proven that following manufacturers instructions in alginate impression taking is an important step in acquiring accurate impressions and tray adhesives may play an important role in enhancing the results.

• The Journal of the Korean dental association
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• v.41 no.1 s.404
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• pp.35-41
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• 2003

Wettability of addition silicone impression material is very important property for making an accurate restoration. This study examined theimpression quality in clinical condition and the wettability of impression material. Three commercially available addition silicone impression material (Imprint; 3M, USA, Examix; GC, Japan, Perfect; Handae, Korea) were studied. A total of 90 putty/wash impressions of semi-dried premolars and wet molar teeth were examined for void production in impression body. The percentae of the sulcus reproduction ability of each material was calculated from the sulcus depths of cross-sectioned casts from the impressions with stereomicroscope. Three impression materials were used to produce die stone casts from vcid entrapment die. Voids in the stone casts were counted with the stereomicroscpe. From the experiment, the following results were obtained: 1. In direct observation, Imprint showed greatest numbers of void in impression body (P<.001).However, correlations were not found between sulcus reproduction and void production. 2. Sulcus reproduction ability of additional silicone impression material was diminished in order of Imprint, Examix, Perfect. The significant difference was found between Imprint and other material (P<.001). 3. In void entrapment laboratory test, void productions was diminished in order of Examix, Imprint, Perfect. All voids in casts were less in delayed poured cast than immediately poured cast. 4. Especially, the stone pouring time of Perfect impression material should be delayed.

• The Journal of Advanced Prosthodontics
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• v.5 no.4
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• pp.369-373
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• 2013

PURPOSE. The objective was to evaluate canine positions, intercanine tip width (ICTW) and width of distal surface of canine (WDC), related to facial landmarks including interalar width (IAW), intercommissural width (ICoW), and distance between left and right projection lines drawn from inner canthus of eyes to alae of the nose (DPICa) in a group of Thai. MATERIALS AND METHODS. One hundred Thai subjects aged 18-35 years were selected. IAW and ICoW were measured on subject's face using digital vernier caliper. Irreversible hydrocolloid impression of the upper arch was taken, and a cast was poured with dental stone. Silicone impression material was used to take imprint of the incisal edge of upper six anterior teeth. DPICa was obtained from the subject's face using custom-made measuring equipment and marked on the silicone incisal imprint. The marks were then transferred from the imprint to the stone cast and measured with digital caliper. The ICTW and WDC were also measured on the stone cast. Pearson's correlation was used to determine the correlation. RESULTS. The results revealed that the correlation between ICTW-ICoW was 0.429 and ICTW-DPICa was 0.573. The correlation between WDC-ICoW was 0.426 and WDC-DPICa was 0.547. However, IAW did not show any correlation with ICTW or WDC (P>.05). CONCLUSION. The correlation between canine position and facial landmarks was found. ICTW and WDC had relationship with ICoW and DPICa. DPICa showed stronger correlation with the position of maxillary canine than that of ICoW.

• The Journal of Korean Academy of Prosthodontics
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• v.43 no.3
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• pp.352-362
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• 2005

Statement of problem. Accurate impression is essential to success of implant prostheses. But there have been few studies about the accuracy of fixture-level impression techniques in internal connection implant systems. Purpose. The purpose of this study was to compare the accuracy of two fixture-level impression techniques in two conditions (parallel and divergent) and to assess the effect of tightening sequences and forces on stresses generated on superstructures in internal connection implant system (Astra Tech). Material and methods. Two metal master frameworks made from two abutments (Cast-to Abutment ST) each and a corresponding, passively fitting, dental stone master cast with four fixture replicas (Fixture Replica ST) were fabricated. Ten dental stone casts for each impression techniques (direct unsplinted & splinted technique) were made with vinyl polysiloxane impressions from the master cast. Strain gauges for each framework were fixed midway between abutments to measure the degree of framework deformation on each stone cast. Pairs of strain gauges placed opposite each other constituted one channel (half Wheatstone bridge) to read deformation in four directions (superior, inferior, anterior, and posterior). Deformation data were analyzed using one-way ANOVA and the Tukey test at the .01 level of significance. And the effect of tightening sequences (right-to-left and left-to-right) and forces (10 Ncm and 20 Ncm) were assessed with ten stone casts made from parallel condition by the splinted technique. Deformation data were analyzed using paired t-test at the .01 level of significance. Conclusions. Within the limitations of this study, the following conclusions could be drawn. 1. Frameworks bent toward the inferior side on all casts made by both direct unsplinted and splinted impression techniques in both parallel and divergent conditions. 2. There was no statistically significant difference of accuracy between the direct unsplinted and splinted impression techniques in both parallel and divergent conditions (P>.01). 3. There was no statistically significant difference of stress according to screw tightening sequences in casts made by the splinted impression technique in parallel condition (P>.01). 4. Greater tightening force resulted in greater stress in casts made by the splinted impression technique in parallel condition (P<.01).

• Journal of the Korean Society of Environmental Restoration Technology
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• v.3 no.4
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• pp.1-10
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• 2000

This study aims at the new design system development of landscape architecture structures, as soundproof wall using reinforced soil block. This structures, that is new soundproof wall system, have to be maintained stability on acting critical wind load, which is combined exist soundproof wall system and soundproof wall system using environmental green stone block. To the harmony of this system, the post block, so-called landscape block or cast block, is manufactured. It's possible to stand of the post bearing system combined with post-pile and post block. Through the comparison with a serious code for the acting wind load on the soundproof wall, the reasonable wind load could be calculated. Also, the mechanical stability on the green stone block was checked by the Lab. tests based on the UBC (Uniformed Building Code). Because the critical height of soundproof wall system using green stone generally was restricted, the new system demands to combination of the exist system and the new system. For the stability analysis of them, the utility program, SAP2000, was used. And, a semi-auto program on the design system of the new soundproof wall using green stone was developed, which can be easily use because of the simplification.