• Restorative Dentistry and Endodontics
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• v.35 no.1
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• pp.30-39
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• 2010

This study evaluated the influence of the type of restoration and the amount of interdental spacing on the stress distribution in maxillary central incisors restored by means of porcelain laminate veneers and direct composite resin restorations. Three-dimensional finite element models were fabricated to represent different types of restorations. Four clinical situations were considered. Type I, closing diastema using composite resin. Labial border of composite resin was extended just enough to cover the interdental space; Type II, closing diastema using composite resin without reduction of labial surface. Labial border of composite resin was extended distally to cover the half of the total labial surface; Type III, closing diastema using composite resin with reduction of labial surface. Labial border of the preparation and restored composite resin was extended distally two-thirds of the total labial surface; Type IV, closing diastema using porcelain laminate veneer with a feathered-edge preparation technique. Four different interdental spaces (1.0, 2.0. 3.0, 4.0 mm) were applied for each type of restorations. For all types of restoration, adding the width of free extension of the porcelain laminate veneer and composite resin increased the stress occurred at the bonding layer. The maximum stress values observed at the bonding layer of Type IV were higher than that of Type I, II and III. However, the increasing rate of maximum stress value of Type IV was lower than that of Type I, II and III.

• Journal of Dental Rehabilitation and Applied Science
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• v.33 no.2
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• pp.163-168
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• 2017

Anterior diastemas are common esthetic problems. One of the challenges in clinical esthetic dentistry is closing anterior diastemas without creating "black triangles" between the teeth. The success of a restorative treatment in anterior teeth depends on the esthetic integration between soft tissues and hard tissues. This report describes the successfully accomplished diastema closure case by producing the emergence profile with natural contours at the gingival-tooth interface and then generating of gingival recontouring process.

• Restorative Dentistry and Endodontics
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• v.36 no.6
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• pp.515-520
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• 2011

One of the most challenging task in closing anterior diastema is avoiding "black triangle" between the teeth. This paper reports a case that the closure of diastema in anterior teeth could be successfully accomplished using direct adhesive restorations and gingival recontouring. The traditional technique using Mylar strip was modified to increase the emergence profile with natural contours at the gingival-tooth interface. Mylar strip was extended out of the sulcus by approximately 1 mm high from the gingival margin, and a small cotton pellet was used to provide the emergence contour. This modified approach is acceptable for the clinical situation.

• 대한치주과학회:학술대회논문집
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• 2001.12a
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• pp.116-116
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• 2001

• 대한치과교정학회:학술대회논문집
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• 1998.10a
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• pp.51-54
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• 1998

• Proceedings of the KACD Conference
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• 2002.05a
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• pp.348-349
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• 2002

• Journal of Dental Rehabilitation and Applied Science
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• v.33 no.4
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• pp.314-320
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• 2017

In the treatment of esthetically important areas such as maxillary anterior teeth, they should be corresponded with surrounding tissues, and shape of the smile line, soft tissue, and hard tissue, also the anatomical shape and proportion of the teeth should be considered as well. Esthetic analysis includes facial analysis which evaluates the proper parallelism between the occlusal plane and the horizontal reference line, dentolabial analysis which assesses the position of the incisal edge and the coherence between the occlusal plane and the commissural line, tooth analysis which evaluates not only esthetics but also morphology and appearance for proper function, and gingival analysis which forms ideal outline of gingival margins. A maxillary anterior diastema can be esthetically restored through the systematic diagnostic approach and treatment planning, and orthodontic, prosthetic, and conservative treatment can be applied for the treatment.

• The korean journal of orthodontics
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• v.34 no.1 s.102
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• pp.71-81
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• 2004

In this study, we attempt to investigate the mechanisms by which PDL cells regulate osteoclast formation and also tc know whether PDL retained their characteristic phenotype during tooth eruption and interdental separation. Rats were prepared at developmental days 21 (pre-root formation), 27(toot development), 34(advanced root formation/eruption) and at later times(adult rats). To induce severe resorption state of alveolar bone and tooth root, interdental separation with brass wire was performed between the lower first and second molars for 2 weeks in adult rats. Rat mandibles were demineralized and embedded in paraffin, and horizontal and frontal section were prepared for immuno-histochemical analysis using PDL-specific protein 22 (PDLs22), receptor activator of NFKB ligand (RANKL) and osteoprotegerin (OPG) antibodies. 1. Root formation and eruption stage of tooth development. 1) PDLs22 immunolocalization was observed in tooth follicle/PDL cells and osteoblasts throught out the root formation and eruption stages of tooth development. 2) RANKL expression became stronger at eruption stage than root formation stage of tooth development. 3) Strong expression of OPG was detected in follice/PDL cells of toot formation stage but it was decreased with tooth eruption. 2. Interdental separation between lower first and second molar 1) Comparared to normal animal, multinucleated osteoclasts and odontoclasts were markedly induced in the alveolar bone and tooth root with PDL remodeling in hematoxylin-eosin section. 2) PDLs22 expression was decreased with interdental separation. 3) RANKL expression was Increased with interdental separation in PDL fibroblasts, osteoblasts, odontoclasts and it lacunae, resorting dentin, cementum and bone matrix. 4) OPG expression was slightly decreased in the PDL cells adjacent to the alveolar bone and root surface with interdental separation. These results suggested that during tooth eruption and tooth movement, RANKL and OPG in the periodontal tissues are important determinants regulating balanced alveolar bone and tooth root resorption. And it is also suggested that PDL cells retained their characteristic phenotype during tooth eruption and interdental separation except for the short period of PDL remodeling.

• Journal of Periodontal and Implant Science
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• v.20 no.1
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• pp.150.2-150.2
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• 1990

• Journal of the Korean Academy of Esthetic Dentistry
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• v.18 no.1
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• pp.79-85
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• 2009

전치부사이의 비정상적 공간이 생기는 원인은 순측소대, 악궁과 치아의 크기 부조화, 악습관, 과잉치, 치주염으로 인한 병적치아이동 등 다양하다. 이러한 일차적인 원인요소들을 먼저 제거한 후 남게 되는 공간을 해결하기 위해서 교정치료 또는 여러가지 보철수복방법을 고려해 볼 수 있다. 보철적으로 치료할 경우, laminate를 이용하여 심미적인 전치부를 만드는 술식은 보존적인 면에서나 심미적인 면에서 유리한 점이 있어 많이 사용되고 있다. 그러나 인접면사이에 비교적 큰 공간이 존재하며, 감소된 치주조직으로 인하여 치간유두의 소실이 많고 직경이 작은 치경부가 노출되었을 경우에는 laminate를 이용하여 공간을 수복하기가 쉽지 않기 때문에, 교정적으로 치아를 이동시킴으로서 보다 심미적인 결과를 얻을 수 있다. 본 증례는 중등도의 치주질환으로 인하여 치주조직이 감소된 상악중절치에서 정중이개의 양이 비교적 크고 치간유두의 소실 및 직경이 작은 치경부가 노출된 환자에서 laminate를 이용하여 심미적인 공간폐쇄를 도모하였다.