• Journal of the Korean Academy of Esthetic Dentistry
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• v.25 no.2
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• pp.98-108
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• 2016

In recent days, perhaps the biggest driver in new material development is the desire to improve restorations esthetics compared to the traditional metal substructure based ceramics or all-ceramic restorations. Each material type performs differently regarding strength, toughness, effectiveness of machining and the final preparation of the material prior to placement. For example, glass ceramics are typically weaker materials which limits its use to single-unit restorations. On the other hand, zirconia has a high fracture toughness which enables multi-unit restorations. This material requires a long time sintering procedure which excludes its use for fast chair side production. Hybrid ceramic material developed for CAD/CAM system is contained improved nano ceramic elements. This new material, called a Resin Nano Hybrid Ceramic is unique in durability of function and aesthetic base compositions. The new nano-hybrid ceramic material is not a composite resin. It is also not a pure ceramic. The material is a mixture of both and consists of nano-ceramic fillers. Like a composite, the material is not brittle and is fracture resistant. Like a glass ceramic, the material has excellent polish retention for lasting esthetics. The material is easily machined by chair side or in a dental lab side, could be an useful restorative option.

• Journal of Dental Rehabilitation and Applied Science
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• v.37 no.3
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• pp.147-156
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• 2021

There are various treatment options such as conventional complete denture, hybrid prosthesis and implant-supported fixed prosthesis for fully edentulous patients. In case of implant-supported fixed prosthesis, compared to removable prosthesis, it is difficult to place the implant in the correct position considering the anatomical contours of the final prosthesis. In this case, a full mouth rehabilitation with implant-supported fixed prosthesis was performed for a patient who required extraction of all remaining teeth due to dental caries and chronic periodontitis. In the implant placement stage, the implant was placed in the desired position using a surgical guide fabricated considering the anatomical contours of the final prosthesis, and the function and esthetics were evaluated through correction and re-fabrication of the fixed provisional restoration. A final restoration of porcelain fused to gold prosthesis was delivered to the patient based on the provisional restoration. To cope with complications such as loosening of screws and fracture of porcelain, a screw-retained type prosthesis was fabricated for the posterior part and a screw-cement-retained type prosthesis for the anterior part. As a result, the patient showed an improved prognosis in terms of functional and esthetics after the final prosthesis was delivered.

• The Journal of Korean Academy of Prosthodontics
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• v.57 no.3
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• pp.263-270
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• 2019

Current trends in restorative dentistry focus on improving the esthetics and keeping the sound dental tissues as long as possible. The aims of this case report were to describe the successful outcome of cubic-phase zirconia laminate veneers for a patient with isolated microdontia by using a digital workflow, and to describe their clinical implications. A 15-year-old female who had isolated microdontia in combination with spacing visited Ajou University Dental Hospital for esthetic treatment. In this case, 6 maxillary anterior teeth were restored with cubic-phase zirconia laminate veneers without tooth structure removal by using a digital impression, computer-aided design (CAD) software, and computer-aided manufacturing (CAM) procedures. At 6-month follow-up, no distinct mechanical and biological complications were detected and the prostheses exhibited satisfactory esthetics and functions. Due to its favorable tissue responses and enhanced translucency, cubic-phase zirconia can be a suitable strategy for a noninvasive esthetic approach.

• Restorative Dentistry and Endodontics
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• v.33 no.1
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• pp.39-44
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• 2008

The treatment of esthetic areas with single-tooth implants represents a new challenge for the clinician. In 1993, a modification of the forced eruption technique, called "orthodontic extrusive remodelling," was proposed as a way to augment both soft- and hard-tissue profiles at potential implant sites. This case report describes augmentation of the coronal soft and hard tissues around a fractured maxillary lateral incisor associated with alveolar bone loss, which was achieved by forced orthodontic extrusion before implant placement. Through these procedures we could reconstruct esthetics and function in a hopeless tooth diagnosed with subgingival root fracture by trauma.

• The Journal of the Korean dental association
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• v.48 no.5
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• pp.391-406
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• 2010

Orthodontic treatment for middle-aged patients has become more commonplace with various reasons including improved socioeconomic status. Understanding of oral status and treatment modalities of middle-aged patients is mandatory for accurate diagnosis and proper treatment planning. This study investigated 100 consecutive patients aged 40s and 50s and 100 aged 20s who had been examined and diagnosed at the Department of Orthodontics, Chonnam National University Dental Hospital. The results were obtained as follows; 1. Gender distribution showed female outnumbered male patients in young-aged adult patients, but middle-aged patients showed similar male and female distribution. 2. The major concern seeking orthodontic treatment was esthetics not only in young-aged but also in middle-aged adult patients, and a number of middle-aged patients were concerned about oral health as well. 3. Considerable number of middle-aged patients were referred by other dental specialties while young-aged adult patients were more self-motivated for orthodontic treatment. 4. Middle-aged adult patients had more missing teeth and periodontal disease than young-aged adults. 5. The most frequently-observed problem was dental spacing in middle-aged patients while dental crowding in young-aged adult patients. Middle-aged patients showed higher prevalence of deep overbite and overjet while most of young-aged adults presented opposite direction of problem in overbite and overjet. 6. Limited orthodontic treatment was required rather than comprehensive treatment in middle-aged patients, and the most common tooth moving area was anterior part of dentition in case of limited treatment. Need of interdisciplinary therapy with other dental specialties was more common in middle-aged patients. 7. Intervention of specific technique such as invisible TP, passive bracketing, passive wire bonding, and lingual orthodontics was more required in middle-aged patients. Considering that middle-aged patients have different characteristics than young-aged adults, the results of the present study suggest that different treatment modalities are required in middle-aged orthodontic patients in order to manage them properly and efficiently.

• Journal of Dental Rehabilitation and Applied Science
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• v.28 no.3
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• pp.253-268
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• 2012

Full-mouth reconstruction of a patient using dental implants is a challenge if there is vertical and horizontal bone resorption, since this includes the gingival area and restricts the position of the implants. however, hard- and soft-tissue grafting may allow the implants to be placed into the desired position. Although it is possible to regenerate lost tissues, an alternative is to use fixed detachable prostheses that restore the function and the esthetics of the gingiva and teeth. Various material combinations including metal/acrylic, metal/ceramic, and zirconia/ceramic have been used for constructing this type of restoration. Other problems include wear, separation or fracture of the resin teeth from the metal/acrylic prosthesis, chipping or fracture of porcelain from the metal/ceramic or zirconia/ceramic prosthesis, and fracture of the framework in some free-end prostheses. With virtually unbreakable, chip-proof, life-like nature, monolithic zirconia frameworks can prospectively replace other framework materials. This clinical report describes the restoration of a patient with complete fixed detachable maxillary and mandibular prostheses made of monolithic zirconia with dental implants. The occluding surfaces were made of monolithic zirconia, to decrease the risk of chipping or fracture. The prostheses were esthetically pleasing, and no clinical complications have been reported after two years.

• The Journal of Korea Assosiation for Disability and Oral Health
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• v.12 no.1
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• pp.6-10
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• 2016

Esophageal atresia is the abnormal development of the esophagus that connects the mouth to the stomach. This birth defect results in the incomplete connection of the esophagus to the stomach causing an inability to swallow properly and breathing difficulties. Surgery is the only treatment for esophageal atresia. Patients undergone an esophageal reconstruction usually suffer from gastroesophageal reflex. A 5-year old boy with congenital esophageal atresia and Sciwitar syndrome visited Seoul National University Dental Hospital because generalized excessive loss of tooth structure. The patient had history of multiple operations for reconstruct esophagus. He had little food intake experience thought oral and had difficulty to swallowing. The patient was generalized severe erosive and decayed state. For patient, the dental procedure under general anesthesia was scheduled due to the multiple caries with erosion and poor cooperation. Under general anesthesia, pulpectomy and restoration as well as extraction was performed. Gastroesophageal reflex is potentially serious condition, with various extraesophageal adverse effects such as dental erosion. To prevent progression of dental caries, dietary counselling and oral hygiene instruction should be reinforced. Also, restorations to erosive teeth will maintain esthetics and function and preserve pulp vitality.

• Journal of Periodontal and Implant Science
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• v.46 no.6
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• pp.362-371
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• 2016

Purpose: The increasing demand for esthetically pleasing results has contributed to the use of ceramics for dental implant abutments. The aim of this study was to compare the biological response of epithelial tissue cultivated on lithium disilicate ($LS_2$) and zirconium oxide ($ZrO_2$) ceramics. Understanding the relevant physicochemical and mechanical properties of these ceramics will help identify the optimal material for facilitating gingival wound closure. Methods: Both biomaterials were prepared with 2 different surface treatments: raw and polished. Their physicochemical characteristics were analyzed by contact angle measurements, scanning white-light interferometry, and scanning electron microscopy. An organotypic culture was then performed using a chicken epithelium model to simulate peri-implant soft tissue. We measured the contact angle, hydrophobicity, and roughness of the materials as well as the tissue behavior at their surfaces (cell migration and cell adhesion). Results: The best cell migration was observed on $ZrO_2$ ceramic. Cell adhesion was also drastically lower on the polished $ZrO_2$ ceramic than on both the raw and polished $LS_2$. Evaluating various surface topographies of $LS_2$ showed that increasing surface roughness improved cell adhesion, leading to an increase of up to 13%. Conclusions: Our results demonstrate that a biomaterial, here $LS_2$, can be modified using simple surface changes in order to finely modulate soft tissue adhesion. Strong adhesion at the abutment associated with weak migration assists in gingival wound healing. On the same material, polishing can reduce cell adhesion without drastically modifying cell migration. A comparison of $LS_2$ and $ZrO_2$ ceramic showed that $LS_2$ was more conducive to creating varying tissue reactions. Our results can help dental surgeons to choose, especially for esthetic implant abutments, the most appropriate biomaterial as well as the most appropriate surface treatment to use in accordance with specific clinical dental applications.

• Journal of Korean society of Dental Hygiene
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• v.7 no.4
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• pp.583-594
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• 2007

The purpose of this study was to conduct a survey on the senses that preliminary dental hygienists have on employment, who applied for the National Dental Hygienist Examination, so that it could provide a basic reference required for fostering good human resources specializing in oral health with a sense of mission and responsibility as professional. To meet these goals, a self-administered questionnaire survey was conducted for participants in a refresher education meeting for preliminary dental hygienists across three major regions(Seoul, Daejeon and Busan), which was held by the Korean Dental Hygienists Association(KDHA) on Jan. 15, 2006. Total 289 sheets of questionnaire were collected, and 262 sheets except invalid or incomplete ones were used for examination and analysis. As a result, this study came to the following conclusions: First, it was found that 40.4% respondents wanted to be employed in dental clinic or hospital. Most respondents(90.1%) answered that faithfulness is most valued as prerequisite qualification for employment in hospital, and highest percentage of respondents(39.3%) wanted to earn 16 to 17 million Korean won annually. For internship opportunities, 61.9% respondents replied that they could willingly accept the internship, provided that basic pay and switchover to regular employee are all assured. Second, as the results of survey on employment circumstances around respondents, it was found that most respondents(58.3%) were employed in dental clinic or hospital, and highest percentage of respondents(35.0%) earned 15 to 16 million Korean won. Third, it was found that interpersonal relationships among employees had most significant effects(4.81) on selection of employment, which was followed by in-house welfare benefits 1(monthly/annual vacation, resting room, etc; 4.56). For possible influential factors on the selection of employment depending on whether employed or not, it was found that there were Significant differences in pay, welfare benefit 2(seminar, orientation, refresher training opportunities, etc), post-wedding continued employment and merit system between employees and non-employees(pE0.05). Fourth, the survey on respondents' occupational senses of dental hygienist showed that major tasks of dental hygienists were represented by oral disease prevention(92.6%), case management(71.5%), oral health education(66.3%), hospital/clinic management and dental management support(10.4%) and public oral health activities(6.7%) respectively. For job satisfaction, it was found that almost half respondents(48.9%) showed satisfaction at their job and 32.6% felt satisfied at and proud of their job. That is, majority of respondents(81.5%) felt satisfied at their job as dental hygienist. For follow-up requirements to qualify for dental hygienists, it was found that 73.3% felt it necessary to give more investments to self-development, 62.2% respondents considered protection of membership's rights as one of future assignments that KDHA should be more committed to. For future social awareness about dental hygienists as occupation, 69.2% respondents expected that they would be better developed and treated as professional. And desired training courses as a part of qualification for professional dental hygienists were represented by case management(services, manners, etc; 33.3%), implant(28.9%), esthetics(correction, prosthesis, whitening; 18.9%) and so on. For an item on working years, it was noted that 75.9% respondents would keep working as dental hygienists as long as they could.

• Journal of Dental Rehabilitation and Applied Science
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• v.33 no.1
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• pp.34-41
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• 2017

Anticonvulsants, calcium channel blockers and immunosuppressants are representative drugs related with gingival enlargement. Clinical signs and symptoms caused by drug-induced gingival enlargment frequently appear within 1 to 3 months after medication. At initial stage, it is limited to attached gingiva but may extend coronally and interfere with esthetics, mastication and speech. Interproximal spaces are common beginning area and pathologic teeth migration could be occurred by the lesion. Withdrawal or substitution of medication would be the most effective treatment of drug-induced gingival enlargement. However, periodontal treatment and further supportive periodontal therapy should be provided where change in medication is impossible. The present study reports the cases which show the resolution of inflammation with spontaneous teeth migration without change in medication. In all cases discussed in this report could be efficiently managed with proper periodontal treatment and further supportive periodontal therapy.