• The Journal of Korean Academy of Prosthodontics
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• v.51 no.1
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• pp.47-51
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• 2013

With the introduction of dental implants, restoration of missing teeth with conventional fixed or removable partial dentures is being replaced with implants. Especially, with young patients, not only longevity but also esthetic factors need to be considered. Implant restorations provide long-term success functionally but, esthetic complications such as, marginal exposure due to gingival recession, loss of the papilla and dark color of metal abutments may occur. Recently, zirconia restorations with CAD/CAM technology provide functional, biocompatible and esthetic restorations possible. All-ceramic restorations using the pressed ceramic technique show better fracture toughness values than those of the conventional porcelain veneering technique. Pressed ceramic technique creates the veneer design in wax and the lost wax technique is used to create the restoration. The final contour of the restoration may be controlled during wax-up. A 22-year old female patient was restored with dental implants and zirconia restorations using the pressed ceramic technique presenting short-term but optimistic prognosis.

• Journal of Dental Rehabilitation and Applied Science
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• v.37 no.4
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• pp.281-293
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• 2021

Patients who went through maxillectomy can have severely impaired swallowing, mastication, and pronunciation functions because of palatal defects. Leakage occurs through the nasal cavity while eating, chewing becomes difficult due to the loss of teeth and alveolar ridges, and oral and nasal passages are not separated, leading to hyper-nasal sound, and significantly reducing the quality of life. To prosthetically reconstruct the defect, the weight of the obturator should be reduced as much as possible to minimize dropout because of gravity, and the bulb of the obturator should be properly extended into the defect to get additional retention and stability. In this case of a partially edentulous patient who underwent additional maxillary resection because of tumor recurrence, a metal framework was designed by applying the basic design principles of removable partial dentures. An obturator with improved retention, stability, and support was fabricated through functional impressions. The patient was satisfied with the improved facial expression, mastication, swallowing, and pronunciation, and showed stable occlusion and oral hygiene management during the follow-up period.

• The Journal of Korean Academy of Prosthodontics
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• v.61 no.4
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• pp.308-315
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• 2023

In the case of a patients who have lost the centric stop and have a staggered occlusion of the residual teeth, various movements occur when the denture is loaded. Implant placement is necessary to reinforce the retention, support, and stabilization elements to reduce denture movement. However, in this case, considering the patient's age, aversion to surgery, and bone loss, implants were not placed and restoration was performed with a removable partial denture. In this case, it is important to set the correct mandibular position for restoration because the patient has a habit of chewing with the remaining teeth. In this case, a stable mandibular position was established using a gothic arch tracing, and good results were obtained by restoring with partial dentures, so this is reported.

• Journal of dental hygiene science
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• v.14 no.4
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• pp.477-487
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• 2014

Of the many pathogenic Candida species, Candida albicans is the main fungal pathogen of humans. The oral environmental factors considered in the Candida albicans colony forming unit test contain both host and microbial factors associated with candidiasis. In particular, Candida biofilms can develop on surfaces of prosthesis. The purpose of this study was to investigate the distribution of oral Candida species between the type of prosthesis and the situation of oral environment in patient with prosthetic appliance. The patients were 30 elderly subjects with different types of prosthesis, 7 who wore denture, 12 who wore implant and 15 who wore removable orthodontic appliance. We used Candida albicans colony forming unit test using saliva to exam the distribution of Candida albicans related with 5 oral environmental factors, gender, smoking or nonsmoking, alcohol/nonalcohol consumption, the type of prosthetic appliance and its treatment duration as well as tooth brushing frequency per day. In conclusion, for the patient's gender, site in the oral cavity and the type of prosthetic appliance and its treatment duration was associated with an increase in the distribution of Candida albicans in saliva. The distribution of Candida albicans within the oral cavity performs to be modulated to varying extents by oral environmental factors and, further investigations are required to elucidate these complex interactions.

• The Journal of Korean Academy of Prosthodontics
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• v.37 no.5
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• pp.581-596
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• 1999

The purpose of this study was to investigate the stress distribution of the abutment and sup-porting tissues according to the slopes and types of the guiding plane of distal extension removable partial dentures. The 3-dimensional finite element method was used and the finite element models were prepared as follows. Model I : Kratochvil type guiding plane with $90^{\circ}$ to residual ridge Model II : Kratochvil type guiding plane with $95^{\circ}$ to residual ridge Model III : Kratochvil type guiding plane with $100^{\circ}$ to residual ridge Model IV : Krol type guiding plane with $90^{\circ}$ to residual ridge Distal extension partial denture which right mandibular first and second molar were lost was used and the second premolar was prepared as primary abutment with RPI type retainer. Then 150N of compressive force was applied to central fossae of the first and second molars and von Mises stress and displacement were measured. The results were as follows 1. Model I and Model IV showed a similar stress distribution pattern and the stress was concentrated on the apex of the root of the abutment. 2. The stress was increased and concentrated on mesial side of the root of the abutment in Model II. The stress was concentrated on buccal and mesiobuccal side of the root of the abutment in Model IV. 3. In Model I, the root of the abutment displaced and twisted a little in clockwise. In Model IV, the root of the abutment displaced to distolingually at apical region of the root and mesiobuccally at cervical region of the root. 4. In Model II, the root of the abutment displaced to mesiolingually at apical region of the root and more displaced and twisted in counterclockwise at cervical region of the root. In Model III, the root of the abutment displaced to mesiobucally at apical region of the root and more displaced and twisted in clockwise at cervical region of the root.

• The Journal of Korean Academy of Prosthodontics
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• v.46 no.4
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• pp.381-395
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• 2008

Purpoose: For decades dental implants have been used widely in the field of prosthetic dentistry. However there is confusion when establishing treatment plans in cases where some teeth are remained but an insufficient number of implants can be used due to limited anatomical status and ecomomical problems. Many clinicians have tried to connect natural teeth and implants, and it still has controversy. But, there have been few studies on mechanical analysis of connecting natural teeth and implants with konus telescopic removable partial dentures. The purpose of this study was to analyze the stress distribution of prosthesis, abutment and alveolar bone when teeth and implants were connected with the konus telescopic denture, by means of 3-dimensional finite element analysis. Material and methods: The assumption of this study was that there were 2 mandibular canine (11 mm in length, 4 mm in diameter) and 2 implants(10 mm in length, 4 mm in diameter) which are located in the second premolar region. The mandible, teeth, implants, abutments, and connectors are modeled, and analyzed with the commercial software, ANSYS Version 8.1(Swanson, Inc., USA). The control group used implants instead of natural teeth. 21038 elements, 23544 nodes were used in experimental group and 107595 elements, 21963 nodes were used in control group, Stress distribution was evaluated under 150 N vertical load on 3 experimental conditions - between teeth and implants (Load case 1), posterior to implants (Load case 2), between natural teeth (Load case 3). Results: 1. In all load cases, higher von mises stress value was observed in the experimental group. 2. Maximum von miss stress observed in all load cases and all locations were as follows ; a. 929.44 Mpa in the experimental group, 640.044 Mpa in the control group in outer crown and connector - The experimental group showed 1.45 times high value compared with the control group. b. 145,051 Mpa in the experimental group, 142.338 Mpa in the control group in abutment - The experimental group showed 1.02times high value compared with the control group. c. 32.489 Mpa in the experimental group, 25.765 Mpa in the control group in alveolar bone - The experimental group showed 1.26times higher value compared with the control group. 3. All maximum von mises stress was observed in load case 2, and maxim von mises stress in alveolar bone was 32.489 Mpa at which implant failure cannot occur. 4. If maximum von mises stress is compared between two groups, the value of the experimental group is 1.02 times higher than the control group in abutment, 1.26 times higher than the control group in alveolar bone. Conclusion: If natural teeth and implants are connected with the konus telescopic denture, maximum stress will be similar in abutment, 1.26 times higher in alveolar bone than the control group. With this result, there may be possible to make to avoid konus telescopic dentures where natural teeth and implants exist together.

• The Journal of Korean Academy of Prosthodontics
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• v.56 no.4
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• pp.287-294
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• 2018

Purpose: The aim of the present investigation was to understand the incidence, prevalence of denture stomatitis in denture wearers, who were over 60 years old, and use the results for a fundamental data to promote public awareness about denture stomatitis and its education tools. Materials and methods: From August 21 to September 8 2017, 500 denture wearers, who were more than 60 years old in Seoul and 4 other metropolitan cities (Busan, Daegu, Gwangju, and Daejeon), received questionnaires. The questionnaires included denture wearers' demographic distributions, specific dental treatment experiences, discomforts with current dentures, their oral health conditions, and the method of denture cleansing. Results: Thirty-two percent of 500 denture wearers responded that they have healthy oral conditions. Two hundred and eight respondents (41.6%) were aware of denture stomatitis. Only 131 (26.2%) were informed about the removable denture covered by national health insurance and 327 (65.4%) of denture wearers were using the improper denture cleansing methods. Conclusion: A large number of denture wearers still do not recognize the importance of proper treatment for denture stomatitis, insurance covered denture treatments, and adequate denture cleansing methods.

• 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.