• 대한치주과학회:학술대회논문집
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• 1994.12a
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• pp.15-17
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• 1994

• Proceedings of the Korean Information Science Society Conference
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• 2001.04b
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• pp.514-516
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• 2001

본 논문은 시차를 두고 촬영된 두 장의 치과용 디지털 X-Ray 영상으로부터 임플란트 시술환자에서 자주 발생하는 임플란트 주위염을 검출하는 자동화된 시계열 분석 방안을 제안한다. 분석자에 따라서 결과의 차이를 보이는 수동적인 시계열분석방법의 문제점을 극복하고 보다 객관적이고 정략적인 결과를 얻는 방안을 제시한다. 보다 신속하고 정확한 검출을 위해서 본 연구에서는 치아의 구조 분석을 통해서 환부 탐색 영역을 줄이고 작은 변화도 민감하게 검출할 수 있는 환부영역을 분리할 수 있는 방안을 제안한다. 또한 분리된 환부의 특성을 수치적으로 표현할 수 있는 방안도 함께 제시된다.

• The Journal of Advanced Prosthodontics
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• v.7 no.2
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• pp.166-171
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• 2015

PURPOSE. The aim of this study was to evaluate antibacterial activity and osteoblast-like cell viability according to the ratio of titanium nitride and zirconium nitride coating on commercially pure titanium using an arc ion plating system. MATERIALS AND METHODS. Polished titanium surfaces were used as controls. Surface topography was observed by scanning electron microscopy, and surface roughness was measured using a two-dimensional contact stylus profilometer. Antibacterial activity was evaluated against Streptococcus mutans and Porphyromonas gingivalis with the colony-forming unit assay. Cell compatibility, mRNA expression, and morphology related to human osteoblast-like cells (MG-63) on the coated specimens were determined by the XTT assay and reverse transcriptase-polymerase chain reaction. RESULTS. The number of S. mutans colonies on the TiN, ZrN and $(Ti_{1-x}Zr_x)N$ coated surface decreased significantly compared to those on the non-coated titanium surface (P<0.05). CONCLUSION. The number of P. gingivalis colonies on all surfaces showed no significant differences. TiN, ZrN and $(Ti_{1-x}Zr_x)N$ coated titanium showed antibacterial activity against S. mutans related to initial biofilm formation but not P. gingivalis associated with advanced periimplantitis, and did not influence osteoblast-like cell viability.

• The Journal of the Korean dental association
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• v.53 no.5
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• pp.318-325
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• 2015

Peri-implantitis is defined as an inflammatory process affecting the tissues around an osseointegrated implant, resulting in the loss of the supporting bone. Microbial adherence and colonization appear to play a major role in the pathogenesis of periimplantitis. The decision regarding treatment strategies is based on the diagnosis. The severity of the peri-implant lesion and the treatment strategies must include mechanical cleaning (infection control) procedures. Mechanical instrumentation is widely used for the debridement of dental implants, but this may alter the titanium's surface properties. Therefore, selection of the type of instrumentation should be made depending on the type of surface to be debrided. Also, patients with dental implants must always be enrolled in a supportive therapy program.

• The Journal of the Korean dental association
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• v.53 no.12
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• pp.906-909
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• 2015

Peri-implantitis is the inflammatory process, such as edema, bleeding, pus, of the mucosa surrounding dental implants. As the symptoms become severe, the surrounding bone is absorbed causing the implant surface to be exposed. Clinicians treat periimplantitis in various ways since a gold standard for the treatment of peri-implantitis has not been established. Various treatment methods include mechanical, chemical surface treatment and surgical excision, and recently decontamination of the implant surface using various types of lasers has been proposed. Thus, this study reviews the types of lasers and its effects that can be used for the treatment of peri-implantitis.

• The Journal of Advanced Prosthodontics
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• v.12 no.1
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• pp.15-21
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• 2020

PURPOSE. The aim of the current study was to analyze treatment concepts of a cohort of German dentists for planning, fabrication, and maintenance of implant-supported fixed and removable restorations. MATERIALS AND METHODS. A questionnaire including queries about experiences with implant-supported restorations as well as prosthetic and maintenance treatment concepts for supplying patients with fixed and removable implant-supported prosthetic restorations was developed and sent to 350 dental offices registered in the municipal area of Leipzig, Germany. RESULTS. An overall total of 62 returned questionnaires were included in the analyses, which relates to a response rate of 17.7%. Participating dentists were more involved in the prosthetic aspects of implant dentistry rather than surgery, while prosthetic concepts such as backward planning, digital processing, and application of all-ceramic materials were not commonly performed. Simple attachments were preferred over complex retention systems in removable implant-supported restorations. Tooth/implant-supported fixed denture prostheses as well as removable denture prostheses with supporting posterior implants were not regarded as a favorable treatment option. CONCLUSION. Within the limitations of the study, the data indicate that dentists favor simple and conventional treatment approaches in implant prosthetics. Prosthetic aspects in the planning of implant-supported restorations are often neglected. Prosthetic treatment guidelines and aspects should commonly be considered in the planning phase of implant-supported prosthetic restorations, and awareness should be increased in postgraduate education.

• International Journal of Oral Biology
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• v.46 no.3
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• pp.111-118
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• 2021

Periodontitis and periimplantitis are caused as a result of dental biofilm formation. This biofilm is composed of multiple species of pathogens. Therefore, controlling biofilm formation is critical for disease prevention. To inhibit biofilm formation, sugars can be used to interrupt lectin-involving interactions between bacteria or between bacteria and a host. In this study, we evaluated the effect of D-Arabinose on biofilm formation of putative periodontal pathogens as well as the quorum sensing activity and whole protein profiles of the pathogens. Crystal violet staining, confocal laser scanning microscopy, and scanning electron microscopy revealed that D-Arabinose inhibited biofilm formation of Porphyromonas gingivalis, Fusobacterium nucleatum, and Tannerella forsythia. D-Arabinose also significantly inhibited the activity of autoinducer 2 of F. nucleatum and the expression of representative bacterial virulence genes. Furthermore, D-Arabinose treatment altered the expression of some bacterial proteins. These results demonstrate that D-Arabinose can be used as an antibiofilm agent for the prevention of periodontal infections.

• International Journal of Oral Biology
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• v.48 no.3
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• pp.19-31
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• 2023

Peri-implantitis is a disease affecting the tissue surrounding dental implants, destroying both soft and hard tissues. A total of 2,015 studies were collected by searching items in the National Library of Medicine, including keywords, such as "peri-implantitis," "microbiota," and "microbiome." Of them, 62 studies were screened and considered eligible for analysis. Only 16 studies qualified all criteria mentioned here: "Using PCR methods for microorganism detection," "Suggesting quantified results," "Stating obvious clinical diagnosis criteria ("Bleeding on probing," "Probing pocket depth," "Suppuration," and "Radiographic bone loss")." Only 8 studies were included in the meta-analysis because the others had special issues. Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, Aggregatibacter actinomycetemcomitans, Prevotella intermedia, and Epstein-Barr virus were the microbiological subjects of analysis. The odds ratio (OR) between the healthy implants and peri-implantitis were calculated for each microorganism to compare two groups, and the forest plots were suggested as the visual materials. P. gingivalis (1.392 < OR < 2.841), T. forsythia (1.345 < OR < 3.221), T. denticola (2.180 < OR < 5.150), A. actinomycetemcomitans (1.975 < OR < 6.456), P. intermedia (1.245 < OR < 3.612), and Epstein-Barr virus (1.995 < OR < 9.383). The species showed that their 95% confidence interval of odds ratio was higher than 1, indicating that they were detected more frequently in periimplantitis than in healthy implants. Meanwhile, other species, such as Fusobacterium nucleatum and Staphylococcus aureus, were not included in the meta-analysis because the number of studies was insufficient.

• The Journal of Advanced Prosthodontics
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• v.10 no.1
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• pp.18-24
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• 2018

PURPOSE. In literature, many studies compare survival rates of different types of FPDs. Most of them compared restorations, which originated from one university, but from different clinicians. Data about restoration survival rates by only one experienced dentist are very rare. The aim of this study was to evaluate the survival rate of all-ceramic FPDs without the blurring effects of different clinicians. MATERIALS AND METHODS. 153 veneered-zirconia FPDs were observed for follow-up. 22 patients received 131 single crowns and 22 bridges. Because of the different bridge lengths, one unit was defined as a restored or replaced tooth. In total, 201 units were included. Only the restorations performed by the same clinician and produced in the same dental laboratory from 2011 to 2016 were included. Considered factors were defined as "type of unit", "type of abutment", "intraoral region", and "vitality". Modified UHPHS criteria were used for evaluation. Statistical analysis was performed using cox-regression. RESULTS. 189 units (94.0%) showed no kind of failure. 5 chippings (2.4%) could be corrected by intraoral polishing. 4 units (1.9%) exhibited spontaneous decementation. These polishable and recementable restorations are still in clinical use. Chippings or decementations, which lead to total failure, did not occur. One unit was completely fractured (0.5 %). Biological failures (caries, periodontitis or periimplantitis) did not occur. The statistical analysis of the factors did not reveal any significant differences. CONCLUSION. Modern all-ceramic FPDs seem to be an appropriate therapy not only for single restorations but for complex occlusal rehabilitations.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.27 no.2
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• pp.178-183
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• 2001

Since the introduction of the concept of osseointegration, the success rate of dental implant has increased dramatically. So, the uses of dental implant in the treatment of partially or fully edentulous patients have played an important role in dental rehabilitation. Regardless of high success rate of dental implant, some amounts of fixtures cannot help failing. We can classify dental implant failure according to timing, causative factor, etc. This study is focused on dental implant fixture failure, occurring during preprosthetic stage. There are various reasons that cause implant failure on this periods, such as improper patient selection, poor bone quality, and periimplantitis, etc. We investigate the survival rate of 1058 fixtures, which installed in 306 patients in our clinic from January 1997 to December 1999, according to type, sex, location, fixture length and width, using Kaplan-Meier product-limit method and to compare each other with log-rank test. Overall survival rate was 96.80%, and 33 implants failed over the preprosthetic stage. Our survey data identified posterior location of mandible as being associated with implant failure(P<0.05).