• Journal of Periodontal and Implant Science
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• 제26권1호
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• pp.117-132
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• 1996

The purpose of this study was to evaluate the bacterial adherence on e-PTFE membrane immersed in whole saliva from subjects with different periodontal status. Experiment involved 3 subject groups: 5 persons with healthy periodontium(probing depth below 3mm and no signs of gingival inflammation including bleeding on probing), 10 patients with gingivitis(probing depth below 3mm and apparent signs of gingival inflammation), and 10 patients with advanced periodontitis(probing depth over 7mm and apparent signs of gingival inflammation). Each disease group was included before and after scaling and root planing treatment. After obtaining whole saliva from each subject, e-PTFE membrane(Gore-Tex periodontal membrane : $GTPM^{(R)}$, W.L. Gore & Associates, Flagstaff, USA) specimens were immersed at room temperature in the saliva aliqouts for 1, 3, 7 days. The weight between pre - and post - immersion in saliva was measured with the analytical balance and the difference was recorded. The specimens were processed for SEM observation. The bacterial adherence on the membrane specimens was evaluated using the scanning electron microscope images. The obtained results were as follows : 1. There was no difference in the weight of bacteria adherent to e-PTFE membrane specimens according to the periodontal status and the immersion periods. 2. As the exposure time to saliva increased, the bacterial adherence to the membrane specimen significantly increased in all groups(P<0.005). 3. As the severity of periodontal disease increased, the bacterial adherence to the membrane specimens significantly increased(p<0.001). 4. After scaling and root planing, the bacterial adherence to the membrane specimens significantly decreased in gingivitis and periodontitis patient group(P<0.001). These results suggest that bacterial contamination on exposed barrier membrane surface be reduced through improvement of periodontal status and oral health environment before and after GTR procedure for the successful outcome.

• 한국정밀공학회지
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• 제26권12호
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• pp.138-145
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• 2009

Custom medical treatment is being widely adapted to lots of medical applications. A technology for 3D modeling is strongly required to fabricate medical implants for individual patient. Needs on true 3D CAD data of a patient is strongly required for tissue engineering and human body simulations. Medical imaging devices show human inner section and 3D volume rendering images of human organs. CT or MRI is one of the popular imaging devices for that use. However, those image data is not sufficient to use for medical fabrication or simulation. This paper mainly deals how to generate 3D geometry data from those medical images. A new image processing technology is introduced to reconstruct 3D geometry of a human body vacancy from the medical images. Then a surface geometry data is reconstructed by using Marching cube algorithm. Resulting CAD data is a custom 3D geometry data of human vacancy. This paper introduces a novel 3D reconstruction process and shows some typical examples with implemented software.

• Journal of Periodontal and Implant Science
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• 제32권1호
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• pp.61-68
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• 2002

The objective of this study was to determine the incidence and distribution of root fusion as well as its sexlinkage in maxillary and mandibular molars. One hundred fifty patients who had eight maxillary and mandibular molars (third molars excluded) were consecutively selected for the study subjects. The subjects provided a total of 1200 molars, i.e., 600 maxillary and 600 mandibular molars. A decision about root fusion was made on the radiographic examination. If a molar had one root and/or roots fused at any part in the root surface, it was considered as having root fusion. The results showed that : (1) 14.1 % of the maxillary molars and 5.8 % of the mandibular molars had a fused root, (2) the prevalence of root fusion in the male was 33 % and 56.4 % in the female, (3) 60 % in the male and 48.8 % in the female had bilaterally paired root fusion, (4) the root fusion was most frequently observed in the maxillary second molar position, but none in the mandibular first position in this study. Within limitations of this study, it can be concluded that, in management of molars with a furcation problem, treatment options such as hemisection and root amputation should be chosen after careful evaluation of root fusion. Further studies are needed to investigate a possible relationship between root fusion and periodontal disease progression.

• Journal of Periodontal and Implant Science
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• 제31권3호
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• pp.531-542
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• 2001

Periodontal debridement is most important procedure in periodontal treatment, because periodontal disease is the biofilm infection. The use of ultrasonic instrument has many clinical advantages compared to classical hand instrument. The introduction of newly developed ultrasonic scaler tips made the use of ultrasonic scaler popular. However the study of tooth substance removal according to the working parameters of ultrasonic scaler with newly developed tips is not sufficient. The purpose of this study is to evaluate the effects of working parameters of piezoelectric ultrasonic scaler with curette tip on casting gold removal. The working parameters was standardized by the sledge device which controls lateral force(0.5 N, 1.0 N, 2.0 N) and power setting was adjusted 2, 4, 8 in P mode and S mode and instrumentation time was 5 seconds. The defect depth and width were measured with profile meter and defect surface was examined by SME. The depth of defect was significantly large in S mode( $39.58{\pm}19.35{\mu}m$) compared to P mode( $8.37{\pm}6.98{\mu}m$). There was significant decrease of depth of defect between 1.0N($32.87{\pm}27.18{\mu}m$) and 2.0N( $14.86{\pm}15.04{\mu}m$). The area of defect was also significantly large in S mode($4482.42{\pm}3551.71{\mu}m^2$) compared to P mode( $922.06{\pm}960.32{\mu}m^2$). There was significant decrease of area of defect between 1.0N($3889.12{\pm}3936.00{\mu}m$) and 2.0N( $974.66{\pm}986.01{\mu}m$). The change of mode did not effect on the width of the defect. The change of power setting did not effect on the depth, width, and area of defect. In spite of limitation of this study it could be concluded that the use of piezoelectric ultrasonic scaler with curette tip on S mode could make significant tooth substance loss.

• Journal of Periodontal and Implant Science
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• 제38권1호
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• pp.15-22
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• 2008

Purpose: The attachment level is strongly associated with tooth loss and provides useful information on patterns of destruction of the periodontium. The presence of horizontal attachment loss would not be detected in clinical measurement. Therefore, the purpose of the present study was to estimate the patterns of periodontal destruction based on the attachment area and horizontal attachment loss in extracted teeth due to severe periodontitis. Materials and Methods: 307 teeth satisfied the criteria for assessment. An indirect method, based on digital images obtained from a digital camera and an image analysis program, was used to calculate the area of root surface and attachment loss and the extent of horizontal attachment loss. The data were analysed using SPSS. Results: No statistically significant differences among root surfaces were observed in anterior teeth on the loss of attachment area. However, in posterior teeth statistically significant differences in palatal surfaces of maxillary and mandibular premolar and molar surfaces compared with buccal surfaces were observed. Horizontal attachment loss was observed in 21.5% of the teeth examined. Frequency of horizontal attachment loss was highest in the maxillary first premolar (34.8%), followed by the maxillary second premolar (27.3%) and maxillary canine (25%). The mean length of horizontal attachment loss was 1.5mm. Conclusion: More meticulous examination will be needed of the palatal surfaces of maxillary and mandibular premolar and molar teeth. The percentage of teeth with horizontal attachment loss greater than 2.1 mm was 5.2%. Considering the length of curette blades, about 5.2% of teeth were not properly debrided. Therefore, Additional supportive therapy such as local drug delivery has to be considered in treatment of the first maxillary, second premolar and canine due to the high prevalence of horizontal attachment loss.

• Journal of Periodontal and Implant Science
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• 제36권2호
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• pp.449-459
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• 2006

DFDBA(Decalcified freeze-dried bone allograft) is one of the allograft materials for periodontal bone regeneration. DFDBA provides an osteoconductive surface and osteoinductive factors. Therefore, DFDBA have been used successfully to regenerate the attachment apparatus during periodontal treatment. But recent studies was reported that wide variations in commercial bone bank preparations of DFDBA do exist, including the ability to induce new bone formation. DFDBA was experimental materials that was recovered, processed, tested, shipped and invoiced through Musculoskeletal Transplant Foundation. MTF(Musculoskeletal Transplant Foundation) is the world largest, non-profit, AATB(American Association of Tissue Banks) accredited tissue bank. The objective of this study was to determine the effects of serial dilutions of a DFDBA on human fetal osteoblastic cell proliferation and their potential to form and mineralize bone nodules. Human fetal osteoblastic cell line(hFOB 1.19) was cultured with DMEM and SSE($1{\mu}g/m{\ell}$,$10{\mu}g/m{\ell}$, $100{\mu}g/m{\ell}$, $1mg/m{\ell}$) at $34^{\circ}C$ with 5% CO2 in 100% humidity. Cell proliferation was significantly increased at $1mg/m{\ell}$, $100{\mu}g$, $10{\mu}g/m{\ell}$, $1{\mu}g/m{\ell}$, $100ng/m{\ell}$, $10ng/m{\ell}$, $1ng/m{\ell}$ of DFDBA after 5 days incubation (p<0.05). Alkaline Phosphatase(ALP) level was significantly increased in $100ng/m{\ell}$, $10ng/m{\ell}$, $1ng/m{\ell}$ of DFDABA(p<0.05). A quantified calcium accumulation was significantly increased at $1ng/m{\ell}$, $10ng/m{\ell}$ of MTF(p<0.05). These results indicated that DFDBA has an inductive effect on bone formation in vitro.

• Journal of Periodontal and Implant Science
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• 제35권3호
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• pp.719-730
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• 2005

The purpose of this study was to compare the effect of tetracycline HCL, Citric acid and PrefGel applied on the root surfaces that planed with periodontal curret with Roto bur. In this study, 20 extracted teeth with advanced periodontal disease were used. The teeth were root planing with periodontal curette and Roto bur. Following root planing, each agents was burnished on the prepared root surface for 3 minutes to find opened dentinal tubules. And then, each specimens were investigated using scanning electron microscope. Amount of remained cementum by loss of tooth substance index and the number of opened dentinal tubules were evaluated to each specimens The results were as follows. 1. Groups treated with periodontal curette were almost seemed no removed. Other groups treated with Roto bur showed partially opened dentinal tubule orifices. 2. Loss of tooth substance index were compared between groups. There was no statistically difference between periodontal curette groups. Between Roto bur groups was alike. But there were statistically differences between periodontal curette and Roto bur groups. 3. At comparing with various root conditioning agents, Tetracycline HCL group took statistically higher than Citric acid and PrefGel in opened dentinal tubules. On the other hand, there was no statistically difference between Citric acid group and PrefGel group. As a result of this study, groups treated with Roto bur showed more cementum removed than groups treated with periodontal curette. In a treatment for regeneration of periodontal tissue, it was regarded that Roto bur should be used and that Tetracycline HCL would be more effective as chemical root conditioning agent.

• Journal of Periodontal and Implant Science
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• 제51권5호
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• pp.329-341
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• 2021

Purpose: Periodontal treatment aims at complete regeneration of the periodontium, and developing strategies for periodontal regeneration requires a deep understanding of the tissues composing the periodontium. In the present study, the stemness characteristics and gene expression profiles of cementum-derived cells (CDCs) were investigated and compared with previously established human stem cells. Candidate marker proteins for CDCs were also explored. Methods: Periodontal ligament stem cells (PDLSCs), pulp stem cells (PULPSCs), and CDCs were isolated and cultured from extracted human mandibular third molars. Human bone marrow stem cells (BMSCs) were used as a positive control. To identify the stemness of CDCs, cell differentiation (osteogenic, adipogenic, and chondrogenic) and surface antigens were evaluated through flow cytometry. The expression of cementum protein 1 (CEMP1) and cementum attachment protein (CAP) was investigated to explore marker proteins for CDCs through reverse-transcription polymerase chain reaction. To compare the gene expression profiles of the 4 cell types, mRNA and miRNA microarray analysis of 10 samples of BMSCs (n=1), PDLSCs (n=3), PULPSCs (n=3), and CDCs (n=3) were performed. Results: The expression of mesenchymal stem cell markers with a concomitant absence of hematopoietic markers was observed in PDLSCs, PULPSCs, CDCs and BMSCs. All 4 cell populations also showed differentiation into osteogenic, adipogenic, and chondrogenic lineages. CEMP1 was strongly expressed in CDCs, while it was weakly detected in the other 3 cell populations. Meanwhile, CAP was not found in any of the 4 cell populations. The mRNA and miRNA microarray analysis showed that 14 mRNA genes and 4 miRNA genes were differentially expressed in CDCs vs. PDLSCs and PULPSCs. Conclusions: Within the limitations of the study, CDCs seem to have stemness and preferentially express CEMP1. Moreover, there were several up- or down-regulated genes in CDCs vs. PDLSCs, PULPSCs, and BMSCs and these genes could be candidate marker proteins of CDCs.

• International Journal of Computer Science & Network Security
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• 제22권10호
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• pp.97-106
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• 2022

Objective. Nanotechnology is spreading among all areas of life, from everyday devices to medicine. The concept of nanotechnology argues that not only can new physical and chemical properties of materials be discovered, but also the new potential of nanostructures when reduced to the nanoscale. The growing interest in the application of nanomaterials in dentistry contributes to the proliferation of the range of nanomaterials used by specialists. The purpose of this review of information sources was to analyze the prospects for the use of nanomaterials in dentistry. Methods. We used the bibliographic semantic method of research, for which we analyzed electronic databases of primary literature sources Scopus, Web of Science, Research Gate, PubMed, MDPI, and MedLine. English-language scientific articles published after 2017 were taken into consideration. Results. According to the results of a search study among modern information primary sources, nanotechnology improves the preventive properties of oral care products, improves the structural-mechanical and aesthetic properties of composite mixtures for dentistry, overcomes the problems of the clinical application of dental implants. Despite the prospects of nanotechnology applications in medicine in general and dentistry in particular, the existing economic and technological problems require a thorough solution for further implementation of nanostructures. Scientific novelty. For the first time, the analysis of modern trends in the application of nanotechnology in dentistry is carried out and the peculiarities of materials are highlighted, the problems and prospects of nanostructures implementation in modern dental implantology are given, physical, chemical, mechanical, and antibacterial properties of nanomaterials are evaluated. The effect of nanomaterials on the microbial adhesion of the tooth or implant surface is described. Practical significance. The presented publication can become a scientific basis for the solution of urgent problems hindering the introduction of nanotechnology into dental practice. Conclusions. Thus, the use of nanostructures opens up great opportunities for the treatment of a wide range of diseases, not only of dental nature but also in medicine in general.

• 구강회복응용과학지
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• 제27권1호
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• pp.1-13
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• 2011

압축강화형 복합레진($TESCERA^{TM}$ ATL)을 지르코니아 framework에 효과적으로 전장하기 위하여, 표면처리 방법을 여러 가지로 달리한 지르코니아 표면에 압축강화형 복합레진을 전장하여 전단결합강도를 실험적으로 비교하였다. 지르코니아의 표면적 증가를 도모하기 위해 최종소결 전 지름 1.1mm round bur를 사용하여 지르코니아 표면에 pockmark (honey-comb concept)를 형성하였고, 화학적으로는 Primer (Zr-plus primer, Bisco, Inc., Shaumurg, USA)를 도포하여 결합강도 증가를 도모하였다. 지르코니아에 porcelain을 적층하여 대조군으로 삼고 각 군을 5도와 55도 사이에서 10,000회 thermocycling시켜 simulated aging 결과 또한 비교하였다. 전단결합강도를 측정하였고 주사전자현미경을 통해 파절단면을 관찰하였다. Pockmark를 형성한 실험군에 압축강화형 복합레진($TESCERA^{TM}$ ATL) 전장 시 도재 전장과 유사한 전단결합 강도를 발휘하였으며,(p>0.05) 동일 시편을 24시간 수중 보관했을 때에 비해 thermocycling 했을 때의 전단결합강도가 약간 감소하였으나 유의차는 보이지 않았다.(p>0.05) 지르코니아 표면에의 Primer의 도포가 압축강화형 복합레진 ($TESCERA^{TM}$ ATL)과의 결합강도를 증가시키지는 못하였다. 지르코니아 소결 전 표면에 pockmark를 주어 표면적을 증가시키고 요철의 효과를 주는 것은 $TESCERA^{TM}$ ATL과의 결합강도를 증가시켰으며, 이는 임상적으로 지르코니아-포세린의 결합강도에 필적하는 강하고 내구성 있는 결합강도를 가져온다고 판단되었다.