• The Journal of Korean Academy of Prosthodontics
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• v.44 no.6
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• pp.677-682
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• 2006

Statement of problem. Various double crown systems have been used with removable partial dentures in the clinical field. Although retentive force between inner and outer crown are affected by several factors, differences between the retentive forces of different double crown system types are expected. Purpose. The purpose of this study was to evaluate the initial retentive force of outer crowns fabricated by the conventional casting technique in conus and hybrid double crowns. Material and methods. Ten double crowns were fabricated. The groups were as follows. Group 1, double crowns of hybrid inner and outer crowns using the conventional casting method; Group 2, double crowns of conus inner and outer crowns using the conventional casting method. Tensile strengths of double crowns when the inner and outer crowns were separated on a universal testing machine were measured. These values of retentive force were then statistically analyzed using the Kruskal-Wallis test. Results. Retentive force in group 2 was significantly higher than that in group 1(p<.05). Conclusion. The initial retentive forces of double crowns were affected by the types of the double crown system.

• The Journal of Korean Academy of Prosthodontics
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• v.20 no.1
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• pp.19-23
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• 1982

귀금속의 가격 앙등은 치과보철치료에 있어서 비귀금속합금의 이용을 촉진 시키고 있다. 가공의치 제작에 비귀금속합금을 이용할 경우에는 납착상태에 대한 신빙성 문제로 인하여 one-piece cast법이 널리 사용되고 있으나 이에 의하여 제작된 가공의치의 적합도에 관하여는 논의가 분분하다. 고로 저자는 one-piece cast법에 의한 비귀금속 가공의치에 있어서 경화수축에 따른 거리변화를 계측현미경을 이용하여 연구한 결과 다음과 같은 결론을 얻었다. 1. 4개 치아를 포함하는 가공의치 제작에 있어서 Hi-Temp 매몰재는 비귀금속합금(Lite-Cast B)의 수축을 보상하고도 남음이 있다. 2. Hi-Temp에 사용되는 액(液)을 증류수로 희석할 경우 그 농도 조절에 의하여 Hi-Temp 매몰재의 팽창을 크게 변화시킬 수 있다. 3. one-piece cast법에 의한 가공의치 제작의 문제점은 두 지대치의 서로 바라보고 있는 인접면간의 거리는 증가됨이 없이 외측 인접면간의 거리만 다소 증가되어야 한다는 것이다. 4. 비귀금속합금을 이용하여 수직적인 큰 변형없이 4개 치아가 포함되는 가공의치를 제작할 수 있다. 5. 수개 치아를 포함하는 가공의치의 주조 정확도를 계측할 수 있는 새로운 방법을 창안하였다.

• Journal of Yeungnam Medical Science
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• v.21 no.1
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• pp.51-59
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• 2004

Background: The objective of this study is to evaluate the relationship between chewing ability and health status in order to provide basic information for the development of program which may lead to an improvement of a the elderly health status in urban areas. Materials and methods: The subjects of this study were 128 elderly urban female over the age of 65 who reside at house. The data were collected from May 21 to August 20, 2001, through questionnaires about nutrient intake status, direct measurement of anthropometrics, and oral examinations. Results: In terms of remaining teeth, there was significant negative relationship between age and number of remained teeth. The average number of remained teeth our subjects was $13.1{\pm}10.6$. About sixty five percent of the subjects were denture users (partial or full dentures) and there was positive relationship between age and the percentage of denture user. There was a significant negative correlation between age and chewing ability. The group that was able to chew had more remained teeth than the other group. Conclusion: This study suggests that there is strong positive relationship between chewing ability (remaining teeth) and elderly health status in urban areas, and the importance of preserving original teeth to improve the elderly health status in the public health program.

• The Journal of Advanced Prosthodontics
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• v.4 no.4
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• pp.254-258
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• 2012

Implant-supported overdenture is a reliable treatment option for the patients with edentulous mandible when they have difficulty in using complete dentures. Several options have been used for implant-supported overdenture attachments. Among these, bar attachment system has greater retention and better maintainability than others. SFI-Bar$^{(R)}$ is prefabricated and can be adjustable at chairside. Therefore, laboratory procedures such as soldering and welding are unnecessary, which leads to fewer errors and lower costs. A 67-year-old female patient presented, complaining of mobility of lower anterior teeth with old denture. She had been wearing complete denture in the maxilla and removable partial denture in the mandible with severe bone loss. After extracting the teeth, two implants were placed in front of mental foramen, and SFI-Bar$^{(R)}$ was connected. A tube bar was seated to two adapters through large ball joints and fixation screws, connecting each implant. The length of the tube bar was adjusted according to inter-implant distance. Then, a female part was attached to the bar beneath the new denture. This clinical report describes two-implant-supported overdenture using the SFI-Bar$^{(R)}$ system in a mandibular edentulous patient.

• Journal of Dental Rehabilitation and Applied Science
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• v.34 no.4
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• pp.306-316
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• 2018

Monolithic zirconia has been widely used in fixed partial dentures due to high strength and fracture toughness. Nevertheless, the usage of monolithic zirconia in anterior restoration was limited because of opacity. Recently, esthetic monolithic zirconia blocks are developed by improving translucency and using various shading systems. Manufacturer introduces 3M $Lava^{TM}$ Esthetic with increased cubic phase and fluorescent ingredients is more esthetic than previous monolithic zirconia. This case report describes favorable anterior restorations using translucent monolithic zirconia.

• The Journal of Advanced Prosthodontics
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• v.11 no.5
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• pp.271-279
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• 2019

PURPOSE. The newest technologies for digital implant impression (DII) taking are developing rapidly and showing acceptable clinical results. However, scientific literature is lacking data from clinical studies about the accuracy of DII. The aim of this study was to compare digital and conventional dental implant impressions (CII) in a clinical environment. MATERIALS AND METHODS. Twenty-four fixed zirconia restorations supported by 2 implants were fabricated using conventional open-tray impression technique with splinted transfers (CII group) and scan with Trios 3 IOS (3Shape) (DII group). After multiple verification procedures, master models were scanned using laboratory scanner D800 (3Shape). 3D models from conventional and digital workflow were imported to reverse engineering software and superimposed with high resolution 3D CAD models of scan bodies. Distance between center points, angulation, rotation, vertical shift, and surface mismatch of the scan bodies were measured and compared between conventional and digital impressions. RESULTS. Statistically significant differences were found for: a) inter-implant distance, b) rotation, c) vertical shift, and d) surface mismatch differences, comparing DII and CII groups for mesial and distal implant scan bodies ($P{\leq}.05$). CONCLUSION. Recorded linear differences between digital and conventional impressions were of limited clinical significance with two implant-supported restorations.

• The Journal of Korean Academy of Prosthodontics
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• v.49 no.2
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• pp.138-144
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• 2011

Purpose: The purpose of this study was to evaluate the cleansing effect of recently developed alkaline ionized water, e-WASH, on microorganisms of the denture surface. Materials and methods: Removable partial and complete dentures were randomly assigned to the experimental group of 41 dentures, and the control group of 26. The denture was immersed in the e-WASH solution (experimental group), or tap water (control group) for 5 minutes. The plaque was collected from the denture surface before and after immersion, and smeared on the slide glass. Amount and motility of microorganisms were compared according to the morphology and strain of microorganisms, using the phase contrast microscope. Statistical analysis was accomplished with paired t-test and independent t-test at 95% confidence level (P<.05). Results: 1. The amount of cocci, bacilli, filamentous, spiral/comma, and the motility of bacilli, filamentous, and spiral/comma were decreased after denture cleansing with the alkaline ionized water, e-WASH (P<.05). But in the control group, only the amount of cocci showed a significant difference (P<.05), but no difference from the others. There were no differences in other analysis. 2. In the experimental group, the amount of cocci, bacilli, filamentous, spiral/comma, and the motility of bacilli, filamentous, and spiral/comma were smaller and more inactive compared to the control group (P<.05). Conclusion: These results indicated that the alkaline ionized water, e-WASH could effectively reduce the amount and motility of the experimented microorganisms on the denture surface, and that e-WASH could be recommended as an effective denture cleanser.

• The Journal of Korean Academy of Prosthodontics
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• v.60 no.1
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• pp.37-43
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• 2022

Patients tend to return to normal pronunciation patterns after fitting new dentures. However, for some patients, it takes a long time to adapt the new complete denture. In this case, the patient came to the hospital at the address of wanting to remake dentures due to wear and tear. After diagnosis through clinical and radiological examination, the maxillary complete denture and mandibular removable partial denture were remade. The patient complained whistling /s/ sound at the first check-up after placement of the new denture. The anterior palatal area of polished surface of the new maxillary complete denture was concave comparing to old denture, and this was the cause of the whistling /s/ sound. A tissue conditioning material was applied to the maxillary complete denture and patient made /s/ sound. The tissue conditioning material was replaced with self-curing type denture base resin, and the patient was immediately satisfied with clear /s/ sound. As an objective assessment, palatogram and speech analytics software was applied. In this case, a patient who received denture treatment complaining of difficulty in pronunciation underwent immediate denture repair, which resulted in patient satisfaction and improved pronunciation through objective evaluation.

• Journal of Dental Rehabilitation and Applied Science
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• v.26 no.3
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• pp.241-251
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• 2010

This study aims at contributing to the restorative dentistry by examining results in the vertical load test of four different low invasive fixed partial dentures. Based on a hypothesis on the right upper first molar is missing, three units of FPDs were made for the second premolar and the second molar abutment. that is, twelve metal dies and FPDs were made for resin bonded FPD and Two Key Bridges and Human Bridge without occlusal rest and Human Bridge with occlusal rest. By using universal test machine, the numerical maximum value were recorded during the vertical load test of each FPDs after the bonding process treated by Maxcem which is resin cement. The failure process and its result of prosthesis were also observed. The maximum load was 7,295 N, 4,729 N, 2,190 N, 3,073 N from groups of resin bonded FPD, Two Key Bridge, Human Bridge without occlusal rest and Human Bridge with occlusal rest respectively. There was a statistical significance among the groups of resin bonded FPD, Two Key Bridge and Human Brides. However, there was no significant difference between Human Bridge without occlusal rest and Human Bridge with occlusal rest. Regarding the failure of prosthesis, the groups of Resin Bonded FPD and Two Key Bridge showed that one of the abutment teeth in the both side of retention part was highly failed earlier than the other one (83.2% and 66.6% respectively). While, Human Bridge without occlusal rest and Human Bridge with occlusal rest showed high percentage of failure in the abutment teeth in the both side of retention part at the same time (91.6% and 58.3% respectively). This study demonstrates that the group of Human Bridges has low resistance to the vertical loads of low invasive FPDs in comparison with the groups of resin bonded FPD and Two Key Bridge. Nevertheless, the maximum occlusal load of the restorative position, resistance to diverse restoration failure, amount of tooth reduction and patients' cooperation should be considered when they are applied in the clinic in order to choose an appropriate restoration for each patient.

• Journal of Digital Convergence
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• v.12 no.6
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• pp.467-479
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• 2014

The purpose of this study was to provide the data for discussion related to oral health promotion policies for the elderly by examining and analyzing the prosthesis conditions and necessity for the fixed and removable dentures among the Korean elderly. The data, obtained from 4,557 elderly aged at 65 or higher who were targeted for the 5th National Health Nutrition Survey, were analyzed through the complex sample frequency analysis, complex sample cross analysis, and complex sample logistic regression analysis. The results of analysis showed significant relevance of whole denture implant and the necessity thereof in older subjects, rural community, and subjects with lower education background, regarding the state of upper jaw/lower jaw prosthesis and the necessity for upper jaw/lower jaw fixed partial denture/whole denture. In addition, the necessity for prosthesis implant was found to have correlation with the income and subjective health condition, while the necessity for artificial teeth(denture) was found to have correlation with the gender, age, education, and subjective oral health condition. Therefore, it is considered necessary to map out the prevention and treatment policies designed to help maintain and promote oral health based on oral health education, along with the policies that aim to recover the neutralized oral health functions, in relation to the oral health of the elderly.