• Journal of the korean academy of Pediatric Dentistry
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• v.36 no.1
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• pp.91-95
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• 2009

The use of stainless steel crowns are indicated for restoration of primary or permanent molars with proximal dental caries, extensive dental caries, or previous pulp treatment with increased danger of tooth fracture. Stainless steel crowns were introduced by Humphrey in 1950. For their improved durability, longevity, and success rate, they have been strongly considered for restoring extensive and multi-surfaced dental caries of molars in pediatric dentistry. However, they also have shortcomings, such as possibility of pulpal exposure or damaging proximal surface of adjacent teeth. In addition, when oversized stainless steel crowns are used, eruption of the adjacent permanent teeth may be disturbed by their prominent margin. As a means to compensate the shortcomings of stainless steel crowns, use of orthodontics bands may be considered. It is an alternative restoration method, where an orthodontic band is placed on a tooth first and cavity is restored with filling material, such as composite resin, glass ionomer, or amalgam. The use of an orthodontic band is indicated for molar restoration with cervical dental caries, extensive dental caries, enamel hypoplasia, or previous pulp treatment. Because it requires shorter chair time compared to stainless steel crown, its application is very useful for children with poor behavior. However, restoration using an orthodontic band requires good oral hygiene after its application. This case report illustrates the conservative restoration of primary molars and permanent molars with extensive dental caries using orthodontic bands.

• Journal of dental hygiene science
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• v.18 no.3
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• pp.155-163
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• 2018

This study's aim was to investigate their opinions to improve the educational system for dental hygienists on the basis of their duties as dental hygienists. The qualitative study was conducted among 19 dental hygienists at Daejeon, Korea from July to August 2016. Two researchers followed each subject for working hours in a day and recorded all the tasks and time to take for each task. After one day, the researchers met each subject and conducted face-to-face interviews to investigate the opinions about the dental hygiene curriculum and national board examination. The main duties recognized by more than half of the subjects were oral disease prevention including scaling and dental treatment assistance. The subjects' minority opinion about the main duties included radiography, impression taking, dental implant surgery assistance, orthodontic treatment, patient counseling, dental management and staff management, and oral health education. The most important tasks perceived by the subjects were prosthetic and implant impressions, scaling and implant surgery assistance. The subjects' minority opinion about the most important duties included patient counseling and making temporary crowns. The most difficult tasks answered by the subjects were prosthetic and implant impressions and dental implant surgery assistance. The subjects' minority opinion about it included patient counseling, scaling, and making temporary crowns. They mentioned that their curriculum in college was different from the actual work and the national board examination was not reflective of their real duties. We found out Korean dental hygienists had a lot of roles as dental assistants, dental business managers, and so on. We suggest that the law, curriculum and national board examination for dental hygienists should be revised to be able to reflect the reality of the clinical field.

• 대한치과보철학회:학술대회논문집
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• 1999.04a
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• pp.79.2-80
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• 1999

• Journal of Technologic Dentistry
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• v.21 no.1
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• pp.123-130
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• 1999

I attempted to suggest a better method to separate a refractory cast in order to solve the problems caused by bonding between refractory casts and ceramics in the firing-processing of all ceramic crowns as a part of dental prosthodontics. I emphasize the advantages and effectiveness of easy separation after firing by using the separating materials about the refractory cast dies. 1. We must not usse HF(55%) that is used as the chemical separating methods. 2. We decrease such methods as grinding, blasting, bur, and point 3. We can save time, costs and manual labors by using this methods. 4. This method regulates the expansion and constriction of heat because of the chemical reaction of the separating materials. 5. This method contribute to the breaking down without modification by minimizing the chemical and mechanical damages of the marginal and interior parts.

• Restorative Dentistry and Endodontics
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• v.45 no.4
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• pp.49.1-49.11
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• 2020

Objectives: The aim of this study was to perform a clinical and radiographic analysis of endodontically treated teeth (ETT) restored with cast metal posts (CMPs) or prefabricated glass fiber posts (GFPs) and crowns. Materials and Methods: Fifty ETT were restored with 25 CMPs and 25 GFPs at a private dental clinic between 2001 and 2016. The restorations consisted of 12 all-ceramic crowns, 31 metal-ceramic crowns, and 7 composite resin crowns. Demographic data, type of teeth, type of post-and-core system, time of placement, crown restorations, the number of proximal contacts, the type of antagonist, and reports of any complications after post-and-core placement were recorded for each patient. Assessments were performed at baseline (radiographic) and follow-up (radiographic and clinical). Data were analyzed by the McNemar test, the Pearson χ² test, and Kaplan-Meier survival curves (α = 0.05). The mean follow-up was 67.6 months. Results: No significant difference was observed for any of the radiographic parameters when the baseline and final radiographs were compared. In the clinical evaluation, anatomical form (p = 0.009) and occlusion (p = 0.001) showed significant differences according to the type of crown restoration; specifically, metal-ceramic and all-ceramic crowns outperformed composite resin crowns. Conclusions: CMPs and GFPs showed favorable results for restoring ETT after 6 years of follow-up. All-ceramic and metal-ceramic crowns showed higher survival rates and better clinical outcomes.

• The Journal of Korean Academy of Prosthodontics
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• v.14 no.1
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• pp.17-21
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• 1976

The author studied the gingival responses to some dental cements in the gingival sulcus around artificial crowns. Abutment preparation for full veneer crown was performed in the canines of the two dogs. The location of cervical margins was about 0.5mm. below the gingival crest. Niranium metal crowns were constructed for the teeth, and cemented with zinc phosphate cement or polycarboxy late cement. In the experimental groups the retained cements in the gingival sulucus were not removed, and in the control groups the cements were removed completely after cementation. The dogs were sacrificed at 3 weeks and 5 weeks respectively after cementation. The gingival responses to these cements were examined histologically. The findings were as follows. 1. There was severe inflammation in the gingiva where the cements had been retained in the gingival sulcus around artificial crowns. 2. There was more severe inflammation in the gingiva which had contacted with zinc phosphate cement than in the gingiva with polycarboxylate cement. 3. There was mild inflammation in the gingiva around the margins of Niranium crowns. 4. The retained cement around the margin of restoration should be completely removed after cementation.

• Journal of Dental Rehabilitation and Applied Science
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• v.38 no.2
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• pp.110-119
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• 2022

When restoration for partially edentulous patients, abutments are not always in favorable positions for making removable partial dentures. Because of these situations, patients are sometimes unsatisfied with the stability and support of their removable partial prostheses. In this regard, removable partial denture using a few implant surveyed crown prostheses can be a good alternative. It can be expected to increase stability and support of removable partial dentures by strategically placing a small number of implants and restoring with implant-supported surveyed crowns. In these cases, the patients who had unilateral residual teeth on mandible were treated with two implant surveyed crowns in the tactical place to have bilateral distribution. After definitive removable partial prosthesis, the patients showed satisfaction with the masticatory function and comfort of using removable dentures.

• The Journal of Advanced Prosthodontics
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• v.7 no.2
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• pp.129-137
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• 2015

PURPOSE. Squamous cell carcinoma (SCC) of the tongue has a relatively high incidence of all oral cancers. Some studies have reported a relationship between intraoral dental prosthesis and SCC of the tongue; however, this relationship remains controversial. The purpose of this study was to investigate the relationship between SCC of the tongue and the positional aspects of dental prosthesis using a retrospective analysis. MATERIALS AND METHODS. A total of 439 patients with SCC of the tongue were diagnosed and treated in the Department of Oral and Maxillofacial Surgery, Seoul National University Dental Hospital. Patients were treated over a 12.5-year period ranging from January 1, 2001 to June 30, 2013. Statistical analysis was performed to examine potential differences between the groups. RESULTS. The number of patients with a crown and/or a bridge (134, 63.5%) was significantly different than the number of patients without a prosthesis (77, 36.5%). Even after accounting for different types of prostheses such as crowns, bridges, and dentures, no significant differences were observed between the position of the prosthesis and the location of the SCC of the tongue, with significance defined as a P-value less than .05 by the Pearson-Chi square test. CONCLUSION. Patients with crowns and/or bridges exhibited more frequent SCC of the tongue compared with patients without these prosthesis. These data support the hypothesis that mechanical trauma and galvanic phenomena play a role in the etiology of SCC of the tongue.

• Journal of Technologic Dentistry
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• v.45 no.3
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• pp.74-80
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• 2023

Purpose: This study aimed to evaluate the fit of the anterior and posterior teeth printed using two light-curing three-dimensional (3D) printers. Methods: Anterior and posterior single crowns were designed using dental software and were printed using 2 types of 3D printers, liquid crystal display (LCD) and digital light processing (DLP) (n=40). After the printed crown was scanned again from inside and outside, the prepared teeth were evaluated using a 3D program. To compare the root mean square (RMS) results among groups (α=0.05), the one-way analysis of variance and Tukey's test were used. Results: No statistically significant difference was found between the mean RMS values of the anterior and posterior teeth (p>0.05). However, as a result of comparing the internal, external, and tooth shapes, the DLP group showed significantly low errors in the inner and outer surfaces than LCD group (p<0.05). Conclusion: In terms of clinical acceptance standard of 100 ㎛, the fit of the anterior and posterior teeth fabricated using LCD and DLP was clinically acceptable.

• The Journal of Korean Academy of Prosthodontics
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• v.40 no.5
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• pp.493-506
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• 2002

Recently as the esthetic concerns about dental prosthesis have been increased, the nonmetallic post and core systems have been introduced clinically to improve the color and the low optical transmittance of conventional casting metal post and core systems. The purpose of this study was to compare and analyze the optical transmittance and the shade changes of all-ceramic crowns with two nonmetallic post and core systems. The experimental groups were classified as follows : Total 27 specimens(9 samples in each group) were evaluated. Group I : Natural teeth as a control group Group II : CosmoPost and $Empress^{(R)}$ core (Ivoclar-Vivadent, Liechtenstein) Group III : $LIGHT-POST^{TM}$ and $LIGHT-CORE^{TM}$ (Bisco, U.S.A.) In all group, all-ceramic crowns were fabricated with the same shade of IPS $Empress^{(R)}$ II (Ivoclar-Vivadent, Liechtenstein) after abutment preparation, and then two kinds of spectrophotometers, UV 3101 PC (Shimadzu, Japan) and CM 503i (Minolta Co. Ltd. Japan), were used to measure the optical transmittance and the color value. The following results were obtained : 1. The optical transmittance of each group without all-ceramic crowns, was siginificantly decreased in order of Group III, I and II (p<0.05). 2. The optical transmittance of each group with all-ceramic crowns cemented, were siginificantly decreased in order of Group I, II and III (p<0.05). 3. In comparison with the shade of all-ceramic crowns, there were no significant differences between groups regardless of the cementation. 4. In comparison with the shade changes in each group after the cementation of all-ceramic crowns, there were no significant differences between groups. From the above results, it is thought that the selection among materials used in this study doesn't influence greatly the esthetic restoration, because the differences of optical transmittance were so small that those were clinically insignificant.