• The Journal of Korean Academy of Prosthodontics
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• v.37 no.3
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• pp.301-312
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• 1999

The purpose of this study was to compare the accuracy of currently used elastomeric impression materials for complete arch impression taking. Five elastomers (Impregum, Permlastic, Express, Extrude, Examix) and one Irreversible hydrocolloid (Aroma-fine) were tested. For each material, 5 impressions were made of stainless steel model to which five tapered posts were attached. Custom trays were used for polyether and polysulfide impression materials, and putty/wash two step technique was used for addition polyvinylsiloxane impression materials. Improved stone mod els were poured to all impressions. Accuracy of the materials was assessed by measuring ten distances on stone dies poured from impressions of the master model. All measurements for master and improved stone models were made with three dimensional measuring machine. The results were as follows 1. The dimensional accuracy of polyether, extrude, and examix were significantly superior to poly-sulfide, exress, and alginate in reproducing full arch mode (p<0.05) 2. There were no statistical differences in dimensional accuracy for full arch impression between polyether extrude and examix (p>0.05). 3. there were no statistical differences in dimensional accuracy between polysulfide, express, and alginate(p>0.05). 4. There were no statistical differences between addition polyvinyl siloxane materials (p>0.05) 5. There were no statistical differences between anterior-posterior and lateral dimensional changes of all impression materials (p>0.05).

• The Journal of Korean Academy of Prosthodontics
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• v.53 no.4
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• pp.330-336
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• 2015

Purpose: This study evaluated the effect of loss of interproximal papilla, creating an undercut, on the accuracy of impression materials. Materials and methods: Two addition type silicone impression materials ($Extrude^{(R)}$ Speed Wash, $Imprint^{TM}$ II Quick Step Light Body) and one alginate impression material (Cavex Impressional) were used to make impressions of a maxillary master model simulating clinical conditions with or without interproximal papilla. Stone was poured in the impressions and working casts were fabricated. A total of 6 groups with 6 working casts in each group were scanned using 3-dimensional optical scanner. The accuracy of the impressions was assessed by measuring the dimensional changes (${\Delta}I$ (%)) of 6 distances on working casts compared to a master model with a 3-dimensional digitizing and inspection software. The data were analyzed by two-way ANOVA (P<.05). Results: Three of 6 distances showed statistically significant differences among the impression materials. Only 1 of 6 distances in alginate impression showed a statistically significant difference between casts with and without interproximal papilla (P=.047). Conclusion: The presence of undercut due to loss of interproximal papilla did not significantly influence the dimensional accuracy of addition type silicone and alginate impression materials.

• Journal of Technologic Dentistry
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• v.10 no.1
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• pp.43-46
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• 1988

The purpose of this investigation was to determined the dimensional change of plaster to time with impression materials. This study was carried out through the literature & experiment, using 4sorts of the Impression Materials(Alginate, Impression Agar, Silicone Rubber, Polysulfide Rybber)and 5 treatments(1hr, 11/2 hrs, 2hur, 3hur, 6hur). The results of this experiment were as follows : 1. Main effect of Impression Meterials & tretments was statistically significant.(P<0.01). 2. The effect of 2-way interaction of Impression materials & Treatments was also statistically significant.(P<0.01) 3. Though this study was the difference of degree according to the materials. All Impression Materials were tended to be constained according to over the time.

• Journal of The Korean Dental Society of Anesthesiology
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• v.14 no.2
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• pp.119-126
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• 2014

Difficulty in breathing can be very disconcerting to a patient who is conscious yet unable to breath normally. The common causes of acute respiratory distress include hyperventilation, vasodepressor syncope, asthma, heart failure, and hypoglycemia. In most of these situations, the patient does not exhibit respiratory distress unless an underlying medical disorder becomes acutely exacerbated. Examples of this include acute myocardial infarction, anaphylaxis, cerebrovascular accident, hyperglycemia, and hypoglycemia. A major factor that leads to the exacerbation of respiratory disorders is undue stress, either physiologic or psychologic. Psychologic stress in dentistry is the primary factor in the exacerbation of preexisting medical problems. Therefore, the most dental patient should be cared gently as the stress reduction protocol. This is a case report of acute respiratory distress with vasodepressor syncope during alginate impression taking of mandibular teeth in a long-standing temporomandibular joint dislocated 93-years-old pneumonic patient.

• The korean journal of orthodontics
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• v.46 no.3
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• pp.129-136
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• 2016

Objective: To investigate the dimensional accuracy of digital dental models obtained from the dental cone-beam computed tomography (CBCT) scan of alginate impressions according to the time elapse when the impressions are stored under ambient conditions. Methods: Alginate impressions were obtained from 20 adults using 3 different alginate materials, 2 traditional alginate materials (Alginoplast and Cavex Impressional) and 1 extended-pour alginate material (Cavex ColorChange). The impressions were stored under ambient conditions, and scanned by CBCT immediately after the impressions were taken, and then at 1 hour intervals for 6 hours. After reconstructing three-dimensional digital dental models, the models were measured and the data were analyzed to determine dimensional changes according to the elapsed time. The changes within the measurement error were regarded as clinically acceptable in this study. Results: All measurements showed a decreasing tendency with an increase in the elapsed time after the impressions. Although the extended-pour alginate exhibited a less decreasing tendency than the other 2 materials, there were no statistically significant differences between the materials. Changes above the measurement error occurred between the time points of 3 and 4 hours after the impressions. Conclusions: The results of this study indicate that digital dental models can be obtained simply from a CBCT scan of alginate impressions without sending them to a remote laboratory. However, when the impressions are not stored under special conditions, they should be scanned immediately, or at least within 2 to 3 hours after the impressions are taken.

• The Journal of the Korean dental association
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• v.43 no.9 s.436
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• pp.576-581
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• 2005

오늘날 알지네이트 인상재는 다른 어떠한 인상재보다 널리 사용되고 있다. 이는 알지네이트 인상재가 ①사용하기 쉽고, ②환자에게 거부감이 적고, ③특수한 장비의 사용이 필요하지 않으며, ④정확히 사용하면 상당히 정밀한 인상이 가능하기 때문이다. 알지네이트 인상재의 정확한 사용법을 정리한다.

• Restorative Dentistry and Endodontics
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• v.43 no.1
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• pp.9.1-9.6
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• 2018

The objective of this case report is to introduce a simple technique for simultaneously taking a closed-mouth impression and functionally generated path (FGP) for a full coverage crown restoration. A monolithic zirconia crown was the restoration of choice. An alginate impression of the abutment tooth was taken to fabricate a custom-made closed-mouth impression tray covering the abutment tooth and the adjacent teeth. The tray had an FGP table and an abutment tray in cameo and intaglio surfaces, respectively. The impression was taken with silicone impression material after adjusting the abutment tray and inscribing the FGP using self-curing acrylic resins. Plaster casts were made from the impression, and a zirconia crown was fabricated. The crown was cemented to the abutment tooth with minimal adjustments. This simple technique resulted in a well-fitting crown that accounted for mandibular movements. Using the custom closed-mouth impression tray incorporating an FGP table simultaneously aids in fabricating an accurately fitting restoration that incorporates harmonious mandibular movements using a single impression capture.

• Journal of Dental Rehabilitation and Applied Science
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• v.31 no.4
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• pp.316-328
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• 2015

Purpose: The objects of this study was to evaluate the accuracy of the dental stone casts made from alginate impressions according to storage condition and stone pouring time. Materials and Methods: Each of upper and lower impressions of dental model was taken. The dental stone models were made immediately, 10, 30, 60, 180, 360 minutes after the impressions were taken at each storage condition. 3D models were constructed by scanning the stone model using 3D laser scanner. With Reference points, positioned on digital models, linear measurements of the dimensional change were compared by 3D metrology software, 3D average models were made and superimposition to identify the specific site of dimensional change and to measure surface deviation (mm). Results: Dental stone models which were made immediately after taking the impression showed the smallest linear dimensional change. As the stone pouring time was prolonged, the linear dimensional change was increased. More than 180 minutes after impression taking, linear dimensional change and surface distortion increased in the posterior molar region, regardless of the storage condition. Conclusion: For the optimum accuracy of the dental stone casts, alginate impression should be poured as soon as possible. If there were a need for storing, a humidor with 100% relative humidity must be used and be stored less than 180 minutes to fabricate the accurate dental model.

• Journal of Dental Rehabilitation and Applied Science
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• v.22 no.1
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• pp.11-21
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• 2006

The adjustable dental impression trays were made for being adjusted their width automatically along the width of patient's dental arch. The purpose of this study was to investigate the retentive force of adjustable dental impression trays made of different synthetic resin materials. Three pairs of adjustable trays were made of ABS(acrylonitrile butadiene styrene) synthetic resin, polyurethane synthetic resin and polycarbonate synthetic resin with a hole and without a rim on the border area of them. The experiment was done with the horse-shoe shaped metal plate to pull out the set impression body from the tray jig which was made for holding the tray on the lower part of Universal Testing Machine(UTM, Zwick Z020, Zwick Co., Germany). After the alginate impression in the tray was allowed to set four minutes, a tensile force was applied at right angles to the tray which had been previously seated on the jig. The force was applied to measure a maximum force by use of UTM at a constant strain rate 100mm per minute. The results obtained in this study were as follows : 1. The upper trays were showed higher retentive force than lower trays in three tray materials. 2. There was no significant difference in the retentive force of the tray materials(p>0.05).

• Analytical Science and Technology
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• v.36 no.3
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• pp.121-127
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• 2023

The detection of blood at a crime scene is an important process for identification and case reconstruction. However, blood may be difficult to observe with the naked eye on dark or multi-colored surfaces. Acidic hydrogen peroxide (AHP) is a recently reported blood enhancement reagent that can enhance blood with high sensitivity by increasing the exposure time of the camera. However, it has never been compared to previously known techniques on dark or multi-colored surfaces. For this purpose, the method of observation/photographing (UV and IR photography), alginate casting, leuco rhodamine 6G (LR6G), and AHP were applied to bloody impression on dark or multi-colored surfaces and the results were compared. As a result, blood treated with AHP had a higher contrast to the surfaces than UV and IR photography, and it was applicable on all surfaces, opposed to alginate casting. In addition, AHP successfully enhanced blood on dark or multi-colored surfaces, similar to LR6G.