• Journal of the Korean Academy of Esthetic Dentistry
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• v.4 no.1
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• pp.1-5
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• 1995

A mucogingival grafting procedure has been developed to cover denuded root surfaces. This procedures need to connective tissue, so many clinician open the trap door to palatal side of the patient. In this study, where palatal pocketing was present, pocket elimination was performed, and the tissue normally discarded after thinning of the palatal flap was used as a grafting material. The esthetics in recipient site, both color match and tissue contour were acceptable to the patient in this case.

• The Journal of the Korean dental association
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• v.55 no.3
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• pp.249-256
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• 2017

Gingival recession is one of the common mucogingival problems during the orthodontic treatment. The causes of the gingival recession are similar to gingival recession in patients with periodontal diseases. Accumulation of bacterial deposits around the natural teeth induces the gingival inflammation and gingival recession occurs in the teeth with the lack of the supporting bone. However, malpositioned teeth which are labially positioned teeth or rotated teeth are more risky for gingival recession. Once root is exposed to oral cavity due to gingival recession, the orthodontic tooth movement is compromised and esthetic problems appeared. In addition, excessive gingival recession over the mucogingival junction jeopardizes the oral hygiene control, which has a risk of further gingival recession and bone loss around the tooth. To cover exposed root or to prevent further gingival recession, mucogingival surgery with gingival graft is recommended for the patients under orthodontic treatment. This case report aimed to present the mucogingival treatments of gingival recession observed during orthodontic treatment. Case I had had initial slight gingival recession before the orthodontic treatment. However, during the retraction phases, the gingival recession progressed and the periodontal treatment was referred. In case II, miller Class III gingival recession was occurred after correction of rotation. Both cases were treated by coronally advanced flap with free gingival grafts and recovered to the level of adjacent teeth despite of complete root coverage was not achieved in Case II. After periodontal treatment, orthodontic treatment was successfully completed. In conclusion, mucogingival surgery during the orthodontic treatment is recommended for the successful orthodontic treatment as well as periodontal health.

• Journal of Broadcast Engineering
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• v.17 no.1
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• pp.81-94
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• 2012

Several methods which utilize the phase of Zernike moments (ZMs) to estimate the rotation angle have shown good performance in terms of accuracy. In this paper, we provides the performance comparison results of the existing rotation angle estimation methods based on ZMs and propose an extension of Revaud et al.'s method [1] which utilizes the phase of ZMs; the proposed method uses angular radial transform coefficients instead of ZMs and yields better performance than the ZMs based methods in terms of accuracy. A set of ART can describe angular variation of image more intensively than ZMs, it enables more accurate estimation of the rotation angle than ZMs. In the experiments, the proposed method outperforms ZMs based method. Comparisons were made in terms of the root mean square error vs. the coverage on MPEG-7 shape dataset.

• Restorative Dentistry and Endodontics
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• v.12 no.2
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• pp.65-72
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• 1987

The purpose of this study was to examine the influence of several root canal sealers on the discoloration of internal surface after root canal obstruction. Twenty four sound human premolars, extracted for orthodontic or prosthodontic purposes, were randomly selected and divided into eight groups. Extracted premolars were prepared, and the following seven materials were introduced into the pulp cavities: AH 26, Fuji ionomer (Type I) cement, N2, Oxypara "Murakami", Kerr sealer, PCA sealer, and G-C's Propac ZOE cement. After 7 weeks of incubation; the discolored tooth crowns were hemisectioned, and the internal staining patterns were examined. Then, with an association of observed values the mean intensity scores and percentage of coverage scores of the internal staining patterns in teeth attained by two observers using for Chisquare test were analyzed. The results were as follows: 1. All the experimental premolar's crown showed various ranged discoloration of internal surface. 2. There was no significance between the association scores of two observers participated into this experiments:% coverage scores (P > 0.05) and intensity (P > 0.05) 3. The crowns filled with PCA sealer, AH 26, and Fuji ionomer cement was visible within a depth of one third of dentin. (P> 0.05) 4. For N2, Kerr sealer, and G-C's Propac cement, A slight dentinal staining was recorded, which penetrated up to half way into the dentin. (P> 0.05) 5. It was noticed that the teeth filled with Oxypara "Murakami" were discolored more than two thirds of the dentinal layer. 6. On the control group, there was no discoloration.

• Journal of the Korean GEO-environmental Society
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• v.20 no.1
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• pp.27-33
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• 2019

Research was initiated to find out acid drainage neutralizing techniques for ecological vegetative growth on the acid drainage slope. Four different acid drainage neutralizing techniques [no treatment, limestone layer treatment, phosphate treatment, and limestone layer + phosphate treatment] were treated on the acid drainage slope. There was a significant difference observed in treated acid neutralizing techniques for acidity, surface coverage rate, death rate and plant root status. Treated acid neutralizing techniques were effective for neutralizing acidity and vegetative growth in order of [first: limestone layer + phosphate treatment, second: phosphate treatment, third: limestone layer treatment and fourth: no treatment]. The limestone layer and the phosphate treatments were effective for neutralizing acidity and vegetative growth, respectively. However, the phosphate treatment was more effective compared to the limestone layer treatment on the acid drainage slope. We figured out that the phosphate treatment is more effective for neutralizing acidity and vegetative growth because of coating effect of sulfides.

• Journal of Periodontal and Implant Science
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• v.52 no.2
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• pp.91-115
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• 2022

Purpose: This systematic review aimed to compare the efficacy, defined in terms of the mean percentage of root coverage (mRC), of surgical treatment approaches combined with adhesive restorations of non-carious cervical lesions (NCCLs) to that of root coverage alone in patients with a single gingival recession (GR) and NCCL. Methods: A literature search was conducted to identify longitudinal studies reporting the mRC following treatment for the correction of GR defects associated with NCCLs using a combination of surgical and restorative techniques in systemically and periodontally healthy patients. Results: The search resulted in the retrieval of 12,409 records. Seven publications met the inclusion criteria for the qualitative synthesis of data. The mRCs ranged from 69% to 97%. In the medium term, the gingival margin position was more stable when a connective tissue graft (CTG) was used, independently of whether restoration of teeth with NCCLs was performed. Conclusions: The strength of the evidence was limited by methodological heterogeneity in terms of study design as well as the unit and period of analysis, which precluded a metaanalysis. Although no definitive conclusion could be drawn due to the lack of sufficient evidence to estimate the effectiveness of the interventions, CTG-based procedures contributed to gingival margin stability regardless of the performance of restoration to treat NCCLs.

• The Journal of Korean Academy of Prosthodontics
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• v.29 no.2
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• pp.35-48
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• 1991

Installation periods of implants in Mx. and Mn., is related to pattern of bone formation. The purpose of this study was to observe histologic response in osseointegration at root formed implant-tissue interface at Mx. and Mn., the other is comparison of osseointegration level between Mx. and Mn. at 8 weeks. In this study, unilateral upper & lower molars were extracted in dog. After allowing to heal for 4 months, two kinds of osseointegrated implants Swedevents, Corevents-were inserted in dog. The specimens were treated by conventional method. The interface zones between bone and implant were investiigated using X-rays, light microscope. The following results were obtained from this study. 1. Around titanium implants that were installed in Ma and Mn., Radio lucencies don't exist 2. There are not inflammation and mobility of titanium implants that were installed in Mx. and Mn. Most of implant surface are covered by bony tissued partly by bone-marrow tissues. 3. Titanium implants installed in Mx, in contrast to same implants in Mn., shows more coverage by bone marrow tissue and lack of apposition lamellar bone, which lead to the assumption that bone formation in Mn. is faster than in Mx.

• Korean Journal of Environment and Ecology
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• v.36 no.3
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• pp.338-349
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• 2022

This study aims to investigate whether modular community planting, which entailed planting a variety of species of seedlings at high density, was more effective in restoring natural forests than the existing mature tree planting. We also investigated whether the planting density of the modular community planting facilitates growth or improves the tree layer coverage. We conducted outdoor experiments in which the samples were divided into a mature tree planting plot (control plot), where mature trees were planted at wide intervals, and a modular community planting (MCP) plot (treatment plot), where multiple seedlings were planted in high density. The MCP plot was further divided into the plot in which 3 seedlings were planted per m² and the plot of 1 seedling per m². We measured the specimens' survival rate, growth rate (tree height, crown width, and root collar diameter), and cover rate for 26 months from May 2019 and the predicted future tree height growth using the measured tree height. The survival rate and relative growth rate of the MCP were higher than those of the mature tree planting plot. The vertical coverage rate of the tree crown in the MCP exhibited complete coverage of the ground before 23 months, while the coverage rate of the mature tree planting decreased due to transplantation stress. The seedlings in the MCP, which were planted at high density, grew well and were predicted to grow higher than the mature trees in the large tree planting plot within 5 to 6.5 years after planting. It was due to multiple species, seedlings, high-density planting, and planting foundation improvements, such as soil enhancement and mulching. In other words, the seedlings planted in the MCP had a higher survival rate as their environmental adaptation after planting was better, and their early growth was also larger than the trees in the mature planting plot. The high-density mixed planting of various native species not only mitigated the inter-complementary environmental pressures but also facilitated growth by inducing competition between species. Moreover, the planting foundation improvement effectively increased the seedlings' viability and growth rate. A reduction in follow-up management costs is expected as the tree layer coverage sharply increases due to the higher planting density. In the MCP (3 seedlings per m² and 1 seedling per m²), the tree height growth was promoted with the higher planting density, and the crown width and root collar diameter tended to be larger with the lower planting density, but these differences were not statistically significant.

• Journal of Periodontal and Implant Science
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• v.30 no.1
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• pp.133-146
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• 2000

Histological studies indicate a tetracycline HCl similar to citric acid to induce connetive tissue repair in animals. When tetracycline HCl was used as a root conditioning agent in humans, there was a trend toward more connective tissue attachment than in root planing alone. The purpose of this study was to evaluate clinical effect of tetracycline HCl in the treatment of gingival recession. 44 teeth in 12 patients with bilaterally gingival recession & Miller classification I, II gingival recession were selected and 22 teeth were treated with 125mg/ml tetracycline HCl , the others was not treated with tetracycline HCl. Gingival recession, pocket depth, clinical attachment level, width of keratinized gingiva were observed at baseline, postoperative 4, 12, 20weeks. Both groups were statistically analyzed by Wilcoxon signed Ranks Test & Wilcoxon's rank sum test(Mann-whitney test) using SPSS program.(5% significance level) The results were as follows: 1........The change of gingival recession, clinical attachment level, keratinized gingiva in both groups were increased significantly at 4, 12, 20 weeks. 2.......The pocket depth exhibited no marked changes throughout the entire investigation in both groups. 3........The change of gingival recession in tetracycline group was increased significantly than control group at 4, 12, 20 weeks and the percentage of root coverage was 93% in tetracycline group and 83% in control group. 4........The change of clinical attachment level, pocket depth, keratinized tissue from baseline to 4, 12, 20 weeks was not differ significanltly in both group.

• Restorative Dentistry and Endodontics
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• v.34 no.6
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• pp.508-514
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• 2009

The purposes of this study were to compare the efficacy of irrigation systems by removing a calcium hydroxide $(Ca(OH)_2)$ paste from the apical third of the root canal and the effect of the patency file. Sixty single rooted human teeth were used in this study. The canals were instrumented by a crown-down manner with .04 taper ProFile to ISO #35. $Ca(OH)_2$ and distilled water were mixed and placed inside the root canals. The teeth were divided into 6 groups according to the root canal irrigation system and the use of patency file as follows: group 1 - conventional method: group 2 - $EndoActivator^{(R)}$: group 3 - $EndoVac^{(R)}$; group 4 - conventional method, patency: group 4 - $EndoActivator^{(R)}$, patency; group 6 - $EndoVac^{(R)}$, patency. All teeth were irrigated with sodium hypochlorite. After the root canal irrigation, the teeth were split in bucco-lingual aspect. Percentage of the root canal surface coverage with residual $Ca(OH)_2$ until 3 mm from working length was analyzed using Image Pro Plus ver. 4.0. Statistical analysis was performed using the One-way ANOVA, t-test and Scheffe's post-hoc test. Conventional groups had significantly more $Ca(OH)_2$ debris than $EndoActivator^{(R)}$, $EndoVac^{(R)}$ groups. There was no significant difference between $EndoActivator^{(R)}$ and $EndoVac^{(R)}$ groups. Groups with patency file showed more effective in removing $Ca(OH)_2$ paste than no patency groups. but. it was no significant difference. This study showed that $EndoActivator^{(R)}$ and $EndoVac^{(R)}$ systems were more effective in removing $Ca(OH)_2$ paste from the apical third of the root canal than conventional method.