• Journal of Technologic Dentistry
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• v.5 no.1
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• pp.19-26
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• 1983

I got a conclusion as a result of that in case of constructing a full denture using acrylic resin teeth, porcelain teeth, and forming posterior occlusal surface of the artificial teeth by Type III Gold and Nickel crome alloy thus construdting a full denture and therefore comparing the above case with abrasion of Natural teeth. The result were as follows : 1. The abrasion of Natural teeth and the abrasion of full denture constructed by Type III gold has a close resemblance. 2. The one that has the hightest degree of abrasion is full denture that's using, with acrylic resin teeth, maxillary and mandibular And the lowest abrasion is natural teeth-natural teeth. 3. In case of single denture, that's opposing to natural teeth, the one that has the hightest degree of abrasion is a full denture that's using Acrylic resin teeth and the lowest abrasion is a full denture that's forming occlusal surface by Type III gold. 4. The single denture, which is opposing to type III gold teeth, was abraded above everything by full denture which is constructed by porcelain teeth. 5. In the same teeth, the abrasion of mandibular teeth was greater than that of mandibular teeth was greater than that of maxillary teeth. 6. The abrasion degree of Acrylic resin teeth has no direct mutual connection with material hardness which is opposing to.

• The Journal of Korean Academy of Prosthodontics
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• v.28 no.1
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• pp.63-94
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• 1990

The purpose of this study was to analyze the displacement and the magnitude and the mode of distribution of the stresses in the lower overdenture, the mucous membrane, the abutment tooth and the mandibular supporting bone when various denture base materials, such as acrylic resin and 0.5mm metal base, and various denture base designs were subjected to different loading schemes. For this study, the two-dimensional finite element method was used. Mandibular arch models, with only canine remaining, were fabricated. In the first denture base design, a space, approximately 1mm thick, was prepared between the denture and the dome abutment. In the second denture base design, contact between the denture and the dome abutment was eliminated except the contact of the occlusal third of the abutment. In order to represent the same physiological condition as the fixed areas of the mandible under loading schemes, the eight nodes which lie at the mandibular angle region, the coronoid process and the mandibular condyle were assumed to be fixed. Each model was loaded with a magnitude of 10 kgs on the first molar region(P1) and 7 kgs on the central incisal region (P2) in a vertical direction. Then the force of 10 kgs was applied distributively from the first premolar to the second molar of each model in a vertical direction(P3). The results were as follows. : 1. When the testing vertical loads were given to the selected points of the overdenture, the overdenture showed the rotatory phenomenon, as well as sinking and the displacements of alveolar ridge, abutment and lower border of mandible under the metal base overdenture were less than those under the acrylic resin overdenture. 2. The maximum principal stresses(the maximum tensile stresses) being considered, high tensile stresses occured at the buccal shelf area, the posterior region of the ridge crest and the anterior border region of the mandibular ramus. 3. The minimum principal stresses(the maximum compressive stresses) being considered, high compressive stresses occured at the inferior and posterior border region of the mandible, the mandibular angle and the posterior border region of the mandibular ramus. 4. The vertical load on the central incisal region(P2) produced higher equivalent stress in the mandible than that on any other region(P1, P3) because of the long lever arm distance from the fixed points to the loading point. 5. Higher equivalent stresses were distributed throughout the metal base overdenture than the resin base overdenture under the same loading condition. 6. The case of occlusal third contact of the abutment to the denture produced higher equivalent stresses in the abutment, the mandibular area around the abutment and the overdenture than the case of a 1mm space between the denture and the abutment. 7. Without regard to overdenture base materials and designs, the amounts and distribution patterns of equivalent stresses under the same loading condition were similar in the mucous membrane.

• The Journal of Korean Academy of Prosthodontics
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• v.43 no.3
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• pp.322-330
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• 2005

Statement of problem. In distal extension removable partial denture, the preservation of health of abutment teeth is very important, but abutment teeth are subjected to unfavorable stress. Purpose. The purpose of this study was to investigate the biomechanical effects of mandibular removable partial dentures with various prosthetic designs using strain gauge analysis. Material and methods. Artificial teeth of both canines were anchored bilaterally in a mandibular edentulous model made of resin. Bilateral distal extension removable partial dentures with splinted and unsplinted abutments were fabricated. Group 1 : Clasp-retained mandibular removable partial denture with unsplinted abuhnents Group 2 : Clasp-retained mandibular removable partial denture with splinted abutments by 6-unit bridge Group 3 : Bar-retained mandibular removable partial denture Strain gauges were bonded on the labial plate of the mandibular resin model, approximately 2 mm close to the abutments. Two vertical experimental loadings (100N and 200N) were applied subsequently via two miniature load cells that were placed at mandibular first molar regions. Strain measurements were performed and simultaneously monitored from a computer connected to data acquisition system. For within-group evaluations, t-test was used to compare the strain values and for between-group comparisons, a one-way analysis of variance (ANOVA) was used and Duncan test was used as post hoc comparisons. Results. Strain values increased as the applied load increased from 100N to 200N for all groups (p<.05). The strain values of group 1 and 2 were tensile under loadings. In contrast, strain values of group 3 were compressive in nature. Under 100N loading, group 1 showed higher strain values than group 3 in absolute quantity (p<.05). Under 200N loading, group 3 showed higher strain values than group 1 and 2 in absolute quantity (p<.05). Group 1 showed higher strain values than group 2 (p<.05). Conclusion. Splinting of two isolated abutments by bridge reduced the peri-abutment strain in comparison with unsplinted abutments. Strain of bar-retained removable partial denture increased much more as applied load increased, but was compressive in nature.

• Journal of Korean Dental Science
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• v.15 no.2
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• pp.152-161
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• 2022

Mandibular implant overdenture is a good treatment option for complete edentulous patients with restoring removable prosthesis. Mandibular implant overdenture with two implants and locator attachments is widely used. It is tissue-supported overdenture that is made with the concept of conventional complete denture fabrication. There are two patients who provided impressions by open mouth technique and closed mouth technique in each case. In both cases, mandibular implant overdentures were restored with functionally and aesthetically satisfying results.

• Journal of the Korean Academy of Esthetic Dentistry
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• v.24 no.1
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• pp.68-74
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• 2015

The growing of healthy aged edentulous peoples in these days increases the demands of denture which is excellent in function and aesthetic. The Biofunctional Prosthetic System(BPS) is being introduced as a curriculum in a large number of schools in the United States, Europe and Japan. Each stages of BPS are standardized and systematized, on this account BPS is the system that even less experienced clinicians is able to produce highly satisfactory denture for patients. Additionally, the combination of BPS and suction mechanism of mandibular complete denture would make it possible to produce stabilized mandibular denture during oral function. The purpose of this article is to describe a process of producing fuctionally and aesthetically outstanding denture by using BPS combined with mandibular suction mechanism.

• The Journal of Advanced Prosthodontics
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• v.8 no.4
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• pp.296-303
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• 2016

PURPOSE. The aim of this study was to evaluate whether there is any typical deformation pattern existing in complete denture when it was dried by using the 3D scanner and surface matching program. MATERIALS AND METHODS. A total of 28 denture bases were fabricated with heat curing acrylic resin (each 14 upper and lower denture bases), and 14 denture bases (each 7 upper and lower denture bases) were stored in the water bottle (water stored), and another 14 denture bases were stored in the air (dry stored). Each specimen was scanned at $1^{st}$ day after deflasking, $14^{th}$ day after deflasking, and $28^{th}$ day after deflasking, and digitalized. Three dimensional deformation patterns were acquired by comparison of the data within storage group using surface matching program. For evaluating differences between groups, these data were compared statisticallyusing Kruskal Wallis and Mann Whitney-U test (${\alpha}$=.05). RESULTS. When evaluating 3D deformation of denture base, obvious deformations were not found in maxillary and mandibular water storage group. However, in dry stored group, typical deformation pattern was detected as storage time passes. It occurred mostly in first two weeks. Major deformations were found in the bilateral posterior area in both maxillary and mandibular group. In maxillary dry stored group, a statistical significance was found. CONCLUSION. It was proved that in both upper and lower denture bases, dry storage caused more dimensional deformation than water storage with typical pattern.

• The Journal of Korean Academy of Prosthodontics
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• v.59 no.1
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• pp.36-42
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• 2021

Even though implant overdentures are preferentially recommended to mandibular edentulous patients, many patients may select conventional complete dentures due to cost and general condition. Proper retention and stability of conventional complete dentures in patients with severe alveolar bone resorption is difficult to achieve. To overcome the limitations, mandibular suction dentures with the closed mouth impression technique have been used. However, the previous technique requires the Frame cut back tray, the Centric tray, and the Gnathometer M. This article introduces a technique for fabricating a mandibular suction denture with common dental materials.

• The Journal of Korean Academy of Prosthodontics
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• v.57 no.3
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• pp.238-244
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• 2019

Soft liner is used to functional impression technique when dental stone is immediately poured after taking impression because of viscoelasticity. In this case, a 78-year-old male visited for new dentures. Due to severe resorption of mandibular edentulous ridge, functional impression taking by closed mouth technique was planned. First of all, making maxillary and mandibular provisional dentures was done, and lined by soft liner to rehabilitate pressured maxillary and mandibular edentulous ridge. After this, Functional impression was taken by closed mouth technique using provisional dentures which are transformed to healed maxillary and mandibular edentulous ridge, and final denture were fabricated using maxillary provisional denture as a reference of artificial teeth arrangement. Consequently, restoring a complete edentulous patient with taking functional impression using provisional dentures resulted in recovering satisfying retention and function.

• Journal of Technologic Dentistry
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• v.46 no.2
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• pp.28-35
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• 2024

Purpose: To evaluate the three-dimensional trueness of upper and lower denture bases produced using a digital light processing (DLP) printer and immersed in a constant-temperature water bath. Methods: An edentulous model was prepared and fitted with denture bases and occlusal rims manufactured using base plate wax. After scanning the model, denture bases, and occlusal rims, complete denture designs were created. Using the designs and a DLP printer, 10 upper and 10 lower complete dentures were manufactured. Each denture was scanned before (impression surface of upper denture base before constant temperature water bath [UBC] and impression surface of lower denture base before constant temperature water bath [LBC] groups) and after (impression surface of upper denture base after constant temperature water bath [UAC] and impression surface of lower denture base after constant temperature water bath [LAC] groups) immersion in the constant-temperature water bath. Scanned files were analyzed by comparing reference and scanned data, with statistical analysis conducted using the Kruskal-Wallis test (α=0.05). Results: Statistical analysis revealed no significant differences between the UBC and LBC groups, nor between the UAC and LAC groups (p>0.05). However, significant differences were observed between the UBC and UAC groups and between the LBC and LAC groups, i.e., before and after the constant-temperature water bath for both maxillary and mandibular denture bases (p<0.05). Conclusion: Denture bases not immersed in the constant-temperature water bath (UBC and LBC groups) exhibited error values within 100 ㎛, whereas those immersed in the water bath (UAC and LAC groups) showed error values exceeding 100 ㎛.

• The Journal of Korean Academy of Prosthodontics
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• v.14 no.1
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• pp.66-71
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• 1976

The purpose of this investigation was to evaluate the mouth preparation and design of removable partial dentures. A total of 187cases for the prefabricated partial denture frameworks in both maxillary and mandibular semi-dentulous situations (66 cases and 203 cases) was selected from this study. The evaluations of mouth preparation and design observed here involved the classification of edentulous spaces, status of abutment splinting with location, design of direct retainer and structure of maxillary major connector according to the incidence of both dental arches, ages, sexes and segment of semidentulousness. The analyzed results were as follows: 1) The order of frequency rate in removable partial denture construction was Class II (50.27%), Class I (36. 90%), Class III (10.69%), and Class IV (2.14 %). 2) The distribution on design of maxillary removable partial denture prosthesis was 33.22% and 64.11% in mandibular removable partial denture prosthesis. 3) The age distribution of removable partial denture prosthesis was prominent after40 years (41.71%). 4) The design pattern of maxillary major connectors was in order of anteroposterior bar, single palatal bar, palatal strap, U-shape connector. 5) The design pattern of direct retainer was in order of Aker's clasp, I-bar clasp, backaction clasp, cuspid universal clasp. 6) The abutment for partial denture clasp splinted between premolar and premolar and its frequency rate revealed 53.44%. 7) It seemed that the location and design of the indirect retainer showed accepatble limit.