• Imaging Science in Dentistry
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• 제30권4호
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• pp.249-254
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• 2000

Purpose: To clarify the clinical and radiologic parameters that can be used to differentiate odontogenic keratocyst and ameloblastoma Materials and Methods: The records of 46 patients of ameloblastoma and 48 patients of odontogenic keratocyst at the Yonsei University Dental Hospital during the period of 1979 to 1995 were retrospectively reviewed. As a possible means for differentiating between the odontogenic keratocyst and ameloblastoma, the clinical parameters and the radiologic parameters were evaluated. Results: In the clinical parameters, there was no significant difference in age, sex, and sign and symptoms (p>0.05). In the radiologic parameters, there was significant difference in site, shape of the lesion, and external root resorption of adjacent teeth (p<0.05). Conclusion: The site, shape of the lesion, and external root resorption of adjacent teeth can be the parameters to differentiate odontogenic keratocyst and ameloblastoma, but a definite differentiation of these two lesions needs a more specialized imaging modality.

• Journal of Periodontal and Implant Science
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• 제31권1호
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• pp.233-242
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• 2001

In the treatment of chronic adult periodontitis, scaling and root planing have been generally performed prior to periodontal flap surgery. The purpose of this study was to evaluate the clinical significance of nonsurgical periodontal therapy prior to periodontal flap surgery in patients with chronic adult periodontitis. Fifty six molars showing bilateral bony defects and 4-6mm periodontal pocket in twelve patients with chronic adult periodontitis were selected. By randomized split-mouth design, in one side, flap operation was performed 4 weeks after scaling and root planing, in the other group, flap operation was only performed without scaling and root planing. Probing pocket depth, gingival recession, clinical attachment level, gingival index, plaque index, and tooth mobility were measured at baseline, before flap operation and post-operation

• Imaging Science in Dentistry
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• 제30권3호
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• pp.199-205
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• 2000

Purpose: To determine whether the significant relationship exists between radiographic appearance, whether it is unilocular or multilocular, and its corresponding clinical and histologic features by examining the odontogenic keratocyst clinically, radiologically and histologically. Materials and Methods: This study was conducted on 48 cases of odontogenic keratocyst from the files of Dental Hospital, Yonsei University for the years 1982 through 1995. Results and Conclusions : The mean age of patients was 30.5 years in the unilocular group and 35.5 years in the multilocular group. The male to female ratio was 1 : 1.06 in the unilocular group and 1 : 1.75 in the multilocular group. The chief complaint was swelling in both groups(unilocular 35.1 %, multilocular 54.5%). In the occurrence site, the border of the lesion, the displacement and external root resorption of the adjacent teeth, there were no statistically significant difference between the unilocular group and multilocular group, but in the border type, there was statistically significant difference (x²-test, p<0.05)wo recurred cases were observed among 11 cases of odontogenic keratocyst. One was unilocular case and the other was multilocular case.

• Restorative Dentistry and Endodontics
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• 제40권4호
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• pp.276-285
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• 2015

Objectives: The purpose of this study was to evaluate the efficacy of mineral trioxide aggregate (MTA), Biodentine and Propolis as pulpotomy medicaments in primary dentition, both clinically and radiographically. Materials and Methods: A total of 75 healthy 3 to 10 yr old children each having at least one carious primary molar tooth were selected. Random assignment of the pulpotomy medicaments was done as follows: Group I, MTA; Group II, Biodentine; Group III, Propolis. All the pulpotomized teeth were evaluated at 3, 6, and 9 mon clinically and radiographically, based on the scoring criteria system. Results: The clinical success rates were found to be similar among the three groups at 3 and 6 mon where as a significant decrease in success rate was observed in Group III (84%) compared to both Group I (100%) and Group II (100%) at 9 mon. Radiographic success rates over a period of 9 mon in Groups I, II, and III were 92, 80, and 72%, respectively. Conclusions: Teeth treated with MTA and Biodentine showed more favorable clinical and radiographic success as compared to Propolis at 9 mon follow-up.

• Restorative Dentistry and Endodontics
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• 제40권1호
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• pp.1-13
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• 2015

Advancements in bio-ceramic technology has revolutionised endodontic material science by enhancing the treatment outcome for patients. This class of dental materials conciliates excellent biocompatibility with high osseoconductivity that render them ideal for endodontic care. Few recently introduced bio-ceramic materials have shown considerable clinical success over their early generations in terms of good handling characteristics. Calcium enriched mixture (CEM) cement, Endosequence sealer, and root repair materials, Biodentine and BioAggregate are the new classes of bio-ceramic materials. The aim of this literature review is to present investigations regarding properties and applications of CEM cement in endodontics. A review of the existing literature was performed by using electronic and hand searching methods for CEM cement from January 2006 to December 2013. CEM cement has a different chemical composition from that of mineral trioxide aggregate (MTA) but has similar clinical applications. It combines the biocompatibility of MTA with more efficient characteristics, such as significantly shorter setting time, good handling characteristics, no staining of tooth and effective seal against bacterial leakage.

• Restorative Dentistry and Endodontics
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• 제46권4호
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• pp.51.1-51.13
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• 2021

Objectives: This study aimed to evaluate the effect of improper positioning single-peak and multi-peak lights on color change, microhardness of bottom and top, and surface topography of bulk fill and incremental composites after artificial aging for 1 year. Materials and Methods: Bulk fill and incremental composites were cured using multi-peak and single-peak light-emitting diode (LED) following 4 clinical conditions: (1) optimal condition (no angulation or tip displacement), (2) tip-displacement (2 mm), (3) slight tip angulation (α = 20°) and (4) moderate tip angulation (α = 35°). After 1-year of water aging, the specimens were analyzed for color changes (ΔE), Vickers hardness, surface topography (Ra, Rt, and Rv), and scanning electron microscopy. Results: For samples cured by single-peak LED, the improper positioning significantly increases the color change compared to the optimal position regardless of the type of composite (p < 0.001). For multi-peak LED, the type of resin composite and the curing condition displayed a significant effect on ΔE (p < 0.001). For both LEDs, the Vickers hardness and bottom/top ratio of Vickers hardness were affected by the type of composite and the curing condition (p < 0.01). Conclusions: The bulk fill composite presented greater resistance to wear, higher color stability, and better microhardness than the incremental composite when subjected to improper curing. The multi-peak LED improves curing under improper conditions compared to single-peak LED. Prevention of errors when curing composites requires the attention of all personnel involved in the patient's care once the clinical relevance of the appropriate polymerization reflects on reliable long-term outcomes.

• 대한치과교정학회지
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• 제46권1호
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• pp.3-12
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• 2016

Objective: The purpose of this study was to compare the precision of three-dimensional (3D) images acquired using iTero$^{(R)}$(Align Technology Inc., San Jose, CA, USA) and Trios$^{(R)}$(3Shape Dental Systems, Copenhagen, Denmark) digital intraoral scanners, and to evaluate the effects of the severity of tooth irregularities and scanning sequence on precision. Methods: Dental arch models were fabricated with differing degrees of tooth irregularity and divided into 2 groups based on scanning sequence. To assess their precision, images were superimposed and an optimized superimposition algorithm was employed to measure any 3D deviation. The t-test, paired t-test, and one-way ANOVA were performed (p < 0.05) for statistical analysis. Results: The iTero$^{(R)}$ and Trios$^{(R)}$ systems showed no statistically significant difference in precision among models with differing degrees of tooth irregularity. However, there were statistically significant differences in the precision of the 2 scanners when the starting points of scanning were different. The iTero$^{(R)}$ scanner (mean deviation, $29.84{\pm}12.08{\mu}m$) proved to be less precise than the Trios$^{(R)}$ scanner ($22.17{\pm}4.47{\mu}m$). Conclusions: The precision of 3D images differed according to the degree of tooth irregularity, scanning sequence, and scanner type. However, from a clinical standpoint, both scanners were highly accurate regardless of the degree of tooth irregularity.

• The Journal of Advanced Prosthodontics
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• 제2권3호
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• pp.111-115
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• 2010

PURPOSE. This study was conducted to evaluate clinical validity of a zirconia full-coverage crown by comparing zirconia's wear capacity over antagonistic teeth with that of feldspathic dental porcelain. MATERIALS AND METHODS. The subject groups were divided into three groups: the polished feldspathic dental porcelain group (Group 1), the polished zirconia group (Group 2), and the polished zirconia with glazing group (Group 3). Twenty specimens were prepared from each group. Each procedure such as plasticity, condensation, and glazing was conducted according to the manufacturer's manual. A wear test was conducted with 240,000 chewing cycles using a dual-axis chewing simulator. The degree of wear of the antagonistic teeth was calculated by measuring the volume loss using a three-dimensional profiling system and ANSUR 3D software. The statistical significance of the measured degree of wear was tested with a significant level of 5% using one-way ANOVA and the Tukey test. RESULTS. The degrees of wear of the antagonistic teeth were $0.119{\pm}0.059\;mm^3$ in Group 1, $0.078{\pm}0.063\;mm^3$ in Group 3, and $0.031{\pm}0.033\;mm^3$ in Group 2. Statistical significance was found between Group 1 and Groups 2 and between Group 2 and 3, whereas no statistical significance was found between Group 1 and Group 3. CONCLUSION. Despite the limitations of this study on the evaluation of antagonistic teeth wear, the degree of antagonistic tooth wear was less in zirconia than feldspathic dental porcelain, representing that the zirconia may be more beneficial in terms of antagonistic tooth wear.

• 대한치과보철학회지
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• 제56권2호
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• pp.134-140
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• 2018

임상치관이 짧아 보철 수복이 어려운 경우 임상치관연장술이 효과적인 치료법이 될 수 있다. 임상치관 연장을 위한 술식에는 수술적 치관연장술, 교정적 정출술, 외과적 정출술이 있는데, 임상상황을 고려하여 최선의 선택을 해야 한다. 수술적 방법과 교정적 방법을 선택할 때, 적절한 고려사항과 주의점에 대해 여러 증례와 함께 보고하고 결정흐름도를 제시하고자 한다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제37권2호
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• pp.133-136
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• 2011

Cystic lesions on the jaws with expansion can invade the adjacent anatomical structure, infiltrate and expand the jaws, cause facial deformity, etc. There is great potential for pathologic fractures after cyst enucleation, and damage to the major structures like the nerve, artery. For these reasons, marsupialization and decompression are commonly used to reduce the cystic size. In 1947, Thomas first mentioned decompression that reduces the osmotic pressure in a cyst by making a hole in the cyst and insert a drain. In our cases, a large sized cystic lesion was treated with a specific device made from an orthodontic band and spinal needle. This device is easy and effective for applications and self irrigation.