• Journal of Technologic Dentistry
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• v.3 no.1
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• pp.9-16
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• 1981

A comparative study was conducted to evaluate the relationship of investing medium to the amount of vertical occlusal changes and to the differences of surface smoothness during denture construction. Three groups of 20 dentures, 30 sets of upper and lower were fabricated of conventional heatcuring acrylic denture base resin, using silicone-gypsum molding techniques, with or without covering the occlusal surfaces of the teeth by artificial stone and all-gypsum molding techniques. The distance between the two reference points indented by 1/2 round bur on the upper and lower frontal surfaces of each articulator were measured and recorded before processing and again after processing and remounting of each denture on the articulator. The differences between the two recordings indicated the amount of vertical opening during denture processing. The difference of surface smoothness were investigated and determined by 3 observers continual comparing of the two randomly selected dentures with each other, which were seperately selected as pairs from the different two groups of 20. The results obtained were as follows: 1. During resin processing no statistically significant differences of the amount of vertical occlusal changes were detected between any of the two groups of two silicone-gypsum and one allgypsum molding techniques, although the amount of vertical opening was somewhat increased when silicone-gypsum molding technique was used. 2. Surface smoothness of the processed denture was makedly by increased when silicone-gypsum molding technique was used.

• The Journal of Korean Academy of Prosthodontics
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• v.37 no.4
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• pp.474-493
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• 1999

According to repeated measurements and correction procedures, the accuracy of the phase-shifting profilometry was developed. At first, after 20 final models for maxillary complete denture were duplicated , the mucosa sur-faces of models were measured with the phase-shifting proflometry and each mirror view of these was calibrated. Maxillary casts were divided into 4 groups of 5 casts per each, and wax dentures with 2 sheets of baseplate wax and artificial teeth were made and then cured according to the curing method of each group. Group I ; quick curing with QC-20 acrylic resin Group II ; 9 hour curing with QC-20 acrylic resin Group III ; SR-Ivocap system Group IV ; metal base and quick curing with QC-20 acrylic resin. After curing, polishing, and storing at $37^{\circ}C$ in saline for 30 days, the forms of the impression surface of the dentures were measured with the phase-shifting profilometry. Then, the impression surface form of each denture was placed in the optimal position of com-parison with the mirror view of the same final cast. The amount and direction of distortion of each denture was analyzed and the effects of polishing and storage in each denture were compared, The obtained results were as follows : 1. In Group I, the denture was observed as the appearance distorted in the opposite direction of the mucosa and the postero-lateral part of palatal portion of the denture was observed as the appearance separated from the mucosa. Also, the buccal flanges of the denture were observed as the appearance distorted in the direction of the mucosa. 2. In Group II, the postero-lateral part of palatal portion of the denture was observed as the appearance separated slightly from the mucosa. The bilateral buccal flanges of denture were observed as the appearance distorted severely in the direction of the mucosa. 3. In Group III the bilateral part of the residual ridge crest portions and the buccal flanges of the denture were observed as the appearance distorted in the direction of the mucosa, and specially, the buccal flanges of the maxillary tuberosities were distorted severely. 4. In Group IV, the acrylic resin base of the buccal portion of the denture was observed as the appearance distorted in the opposite direction of the mucosa. 5. The phase-shifting profilometry, done with repeated measurements and correction procedures, was effective in comparing the amount and direction of distortion at every position after the laboratory work and the delivery of maxillary complete denture.

• The Journal of Korean Academy of Prosthodontics
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• v.33 no.2
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• pp.231-239
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• 1995

When the complete denture is made, the record base for jaw relation is divided into temporary record base and permanent record base. However, The temporary record base include some disadvantages such as, the lackness of intimate contact between model and base, the lackness of retention during the jaw relation registration, When we obtained jaw relation the permanent record bases made from heat curing resin were utilized. We could get several advantages as follows : 1. The permanent record base provided intimate contact between the model and record base. 2. In fabricating occlusal rim on record base, the dimensional change of record base was little because the permanent record base was lesser influenced to thermal change of occlusal rim than the temporary record base. 3. At the stage of jaw relation, the retention of final denture could be early checked. 4. It could be able to get more accurate registration of jaw relation because all procedure were done on the same base during the jaw relation, artificial teeth arrangement, try-in, and final denture construction. 5. Although there was an inconvenience due to double curing procedure, the shrinkage rate in resin polimerization was relatively reduced so that more dimensional stability could be taken.

• Journal of Technologic Dentistry
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• v.40 no.4
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• pp.217-224
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• 2018

Purpose: The aim of this study was to evaluate accuracy of three type complete mandibular denture of before and after polymerization. Methods: Mandibular edentulous model was selected as the master model. 15 study models were made by Type IV stone. Wax complete mandibular dentures were produced by the denture base and artificial teeth. Before and after curing, STL files were obtained using a blue scanner. By superimposing the digitized complete mandibular denture data(after curing) with the CAD-reference(before curing) three-dimensionally, visual fit-discrepancies were drawn by calculating the root mean square (RMS) and visualized on a color-difference map. Each calculated RMS-value was statistically analyzed by 1-way analysis of variance(ANOVA) (${\alpha}=.05$). Results: Mean(SD) RMS-values was OM group $88.98(6.10){\mu}m$, BM group $82.35(13.46){\mu}m$, BDM group $77.83(9.46){\mu}m$. The results of the 1-way ANOVA showed no statistically significant differences in the RMS values of the Three groups for the material (P > .241). Conclusion : Deformation of artificial teeth position was observed in all groups after resin polymerization. But the values, all group were within the clinically acceptable range. The values of BDM group showed the least deformation than the other two groups.

• The Journal of Korean Academy of Prosthodontics
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• v.60 no.2
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• pp.202-210
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• 2022

Recently with the advance in digital dentistry, the fabrication of dentures using computer-aided design and computer-aided manufacturing (CAD-CAM) is on the rise. The denture designed through a CAD software can be produced in a 3-dimensional manufacturing process. This process includes a subtractive processing method such as milling and an additive processing method such as 3D printing and in which it can be applied efficiently in more complex structures. In this case, complete dentures were fabricated using Stereolithography (SLA)-based 3D printing to shorten the production time and interval of visits in patient with physical disabilities due to cerebral infarction. For definitive impression, the existing interim denture was digitally replicated and used as an individual tray. The definitive impression obtained with polyvinyl siloxane impression material was including information about the inclination and length of the maxillary anterior teeth, vertical dimension, and centric relation. In addition, facial scan data with interim denture was obtained so that it can be used as a reference in determination of the occlusal plane and in arrangement of artificial teeth during laboratory work. Artificial teeth were arranged through a CAD program, and a gingival festooning was performed. The definitive dentures were printed by SLA-based 3D printer using a FDA-approved liquid photocurable resin. The denture showed adequate retention, support, and stability, and results were satisfied functionally and aesthetically.

• The Journal of Korean Academy of Prosthodontics
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• v.47 no.1
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• pp.82-90
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• 2009

Statement of problem: Recently, as patients' expectation and interest for esthetics are increasing, concerns of esthetic restoration for removable dentures as well as fixed prosthodontics are also increasing. And the color stability of artificial teeth will affect a long term success rate of the denture. But the stain or discoloration of these artificial teeth as well as denture resin has caused esthetic problem. Purpose: This study was designed to evaluate the influence on color stability of artificial teeth when soy sauce, red pepper paste and coffee which many Koreans have eaten were applied. Material and methods: For artificial teeth type(Endura $Anterio^{(R)}$, Physio $Duracross^{(R)}$, Trubyte $Biotone^{(R)}$) selected for the study, 10 specimens each were soaked into individual beakers of soy sauce, red pepper paste, coffee and distilled water. And $L^*$, $a^*$, $b^*$ value were measured for evaluation of the color difference (${\Delta}E^*$) with spectrophotometer on the 1 day, 1 week, 2 weeks, 4 weeks and 8 weeks after immersion. Results: 1. ${\Delta}E^*$ value of artificial teeth which were soaked in soy sauce and coffee was various according to soaking periods. However there was significant difference between Trubyte $Biotone^{(R)}$ and Physio $Duracross^{(R)}$ in red pepper paste regardless of soaking period(P<.05). 2. Except for 8 weeks of Endura $Anterio^{(R)}$, 4 weeks and 8 weeks of Physio $Duracross^{(R)}$, artificial teeth soaked in red pepper paste regardless of the type had significant difference of ${\Delta}E^*$ value compared with other groups (P<.05). 3. $a^*$, $b^*$ value of Endura $Anterio^{(R)}$ and Trubyte $Biotone^{(R)}$ which were soaked in red pepper paste had significant difference compared with the value of other group(P<.05). Conclusion: Red pepper paste had the greatest effect on color difference of artificial tooth. Physio $Duracross^{(R)}$ showed relatively less color difference than Trubyte $Biotone^{(R)}$ and Endura $Anterio^{(R)}$. But as ${\Delta}E^*$ difference were all less than 3.3, these artificial resin teeth seemed appropriate for clinical use.

• Journal of Technologic Dentistry
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• v.40 no.4
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• pp.201-207
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• 2018

Purpose: The purpose of this study is to evaluate the fitness of lower jaw compete denture with glass fiber. Methods: Lower jaw edentulous model was selected as the master model. Ten study models were produced using Type IV stone(n=10). Lower jaw trial dentures were produced by the wax denture base and artificial teeth. Conventional complete denture (CD) group was fabricated by excluding glass fiber reinforcement (n=5). Glass fiber complete denture (GD) group was fabricated with glass fiber reinforcement (n=5). The lower jaw trial complete denture was invested using a plaster. PMMA resin was injected and curing was performed. The CD and GD groups measured the fit using silicone replica technology. The measured data was verified by t-test. Results: The anterior area of the CD group showed the smallest value. There was a statistically significant difference in the anterior area of the CD group and the GD group (p<0.05), but there was no statistically significant difference in the posterior area (p>0.05). Conclusion : Complete denture with glass fiber showed low fitness and further study is needed to apply it clinically.

• Journal of Dental Rehabilitation and Applied Science
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• v.36 no.2
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• pp.121-127
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• 2020

Prosthodontic decision and management should be considered the patient's aesthetic need for anterior teeth in maxillary edentulism. This case report describes 10-year clinical outcome of a maxillary edentulous patient was rehabilitated by means of an implant-supported fixed dental prosthesis (ISFDP) for the anterior region and a distal-extension removable partial denture (RPD) for the posterior region. The ISFDP was designed to splint 4 endosseous implants as one unit and engaged by the RPD. The edentulous mandible was restored by means of an implant-supported overdenture. Over the course, no major adverse event occurred other than wear, discoloration, and breakage of resin veneers and artificial teeth.

• Journal of Korean Dental Science
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• v.10 no.1
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• pp.29-34
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• 2017

Purpose: The purpose of this study was to evaluate the microleakage of various types of resin-bonded fixed partial dentures (RBFPDs) after artificial aging. Materials and Methods: Forty models with missing first molar were fabricated using artificial resin teeth and were divided into four groups: Group A, conventional RBFPDs design; Group B, modified RBFPDs design; Group C, assembled 3-piece RBFPDs design; and Group D, assembled 3-piece RBFPDs with different occlusal rest positions. Half of the specimens underwent chewing simulation process (240,000 cycles, 50 N load, 1.7 Hz) and thermocycling (temperatures $5^{\circ}C{\sim}55^{\circ}C$, dwelling time 30 seconds) and the remaining 20 specimens didn't receive any treatment. All the specimens were immersed in 2% methylene blue solution for 24 hours to evaluate microleakage, and were sectioned at the middle part of abutment teeth. To evaluate the microleaskage, a dye penetration was calculated. Result: With artificial aging, cyclic loading and thermocycling, a 3-piece RBPFD and a 2-piece RBPFD using original tooth undercuts have significantly lower microleakge (P<0.05) compared to the conventional design of RBPFD and modified RBPFD. Conclusion: Within the limit of this experiment, the assembled RBFPDs exhibited a smaller microleakage than the conventional RBFPDs, implying that the assembled RBFPDs can be more effective for reducing the dislodgement of the RBFPDs.

• The Journal of Korean Academy of Prosthodontics
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• v.30 no.3
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• pp.457-478
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• 1992

Electrical resistance strain gauges, brittle-coatings, Moir'e fringe analysis, photoelasticity methods, etc, have been employed in the study of stress analysis and three-dimensional photoelasticity method used in this experiment. The author fabricated a total of 24 samples of maxillary and mandibular edentulous ridges with normal and sharp shapes using epoxy resin, one of the photoelastic materials. In addition, complete denture made from artificial resin teeth in other twoo sizes, large and medium size, were affixed to the specimens and attached to an articulator. The following results were attained by cutting 9 slice specimens into 6mm thick portions, in accordance with the three dimensional photoelastic stress freezing method, to analyze stress distribution status under specific static loading in the central, lateral and protrusive occlusions of the shape of edentulous ridge. 1. In the case of central occlusion, when complete resin artificial teeth in large and medium sizes were used on normal and sharp alveolar ridges, high stress distribution was broadly shown in the labio-buccal sides, and low and concentrated in the lingual sides, in all cases. Generally, the highest stresses were shown at the top of the alveolus, or at 2mm below the top of the alveolus, particularly in the specimen 2, 3, and stresses were more or less the same in the symmetrical right and left sides. 2. In the case of lateral occlusion, when the same load was applied, high stresses were shown broadly at the working sides in both the labio-buccal and lingual sides, and low and concentrated at the balanced sides. The highest stresses were shown in the top of the alveolus on the working sides in specimen 2 portion, and the lowest stresses at the balanced sides in specimen 6, slightly higher stresses were shown at retromolar parts in the balanced sides. 3. In the case of protrusive occlusion, high stresses were broadly shown at the labio-buccal sides, and slightly higher stresses at the top 2, 4, and 6mm parts of the alveolus with concentration. The highest stresses were shown in specimen No. 5 and the lowes stresses in specimen 1, 9 and stresses were more of less the same at the symmetrical right and left sides.