• 구강회복응용과학지
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• 제31권2호
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• pp.150-157
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• 2015

이 증례 보고의 목적은 임플란트 근단병소를 가진 임플란트를 다양한 임상적 치료 적용 후 5 - 12년간 관찰하여 효과적인 임상적 접근 방법을 제시하고자 한다. 세 명의 환자 중 한 명은 병적 증상이 관찰되지 않아 비활성형(inactive form)으로 진단하고, 부가적인 치료 없이 주기적 관찰을 시행하였다. 두 명의 환자는 통증을 호소하여 감염형(infected form)으로 진단하고, 2 - 3주간 전신적인 항생제를 처방하였다. 한 명은 증상이 개선되어 주기적인 관찰을 시행하고 있으나, 다른 한 명에서는 임플란트 근단병소의 크기가 증가하고 통증의 개선도 보이지 않아 임플란트를 제거한 후 재식립 후 보철치료를 완료하였다. 세 환자 모두 현재까지 기능적 이상 없이 임플란트를 사용하고 있다. 임플란트 근단병소의 발생을 예방하기 위해서는 수술 과정 중 골 괴사를 유발할 수 있는 과열 등의 수술적 외상을 최소화하는 것이 필요하며, 임플란트 근단병소가 발생하였을 경우에는 조기 진단을 통해 적절한 전신적 항생제 처방이나 필요한 경우 외과적 처치를 통해 임플란트의 성공을 높일 수 있을 것으로 생각된다.

• Imaging Science in Dentistry
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• 제45권4호
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• pp.253-261
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• 2015

In this study, we formulate a new proposal that complements previous classifications in order to assist dental practitioners in performing a differential diagnosis based on patients' radiographs. We used general search engines and specialized databases such as Google Scholar, PubMed, PubMed Central, MedLine Plus, Science Direct, Scopus, and well-recognized textbooks to find relevant studies by using keywords such as "jaw disease," "jaw lesions," "radiolucent rim," "radiolucent border," and "radiolucent halo." More than 200 articles were found, of which 70 were broadly relevant to the topic. We ultimately included 50 articles that were closely related to the topic of interest. When the relevant data were compiled, the following eight lesions were identified as having a radiolucent rim: periapical cemento-osseous dysplasia, focal cemento-osseous dysplasia, florid cemento-osseous dysplasia, cemento-ossifying fibroma, osteoid osteoma, osteoblastoma, odontoma, and cementoblastoma. We propose a novel subcategory, jaw lesions with a radiolucent rim, which includes eight entities. The implementation of this new category can help improve the diagnoses that dental practitioners make based on patients' radiographs.

• 대한치과보존학회:학술대회논문집
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• 대한치과보존학회 2003년도 제120회 추계학술대회 제 5차 한ㆍ일 치과보존학회 공동학술대회
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• pp.591-591
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• 2003

Apical periodontitis is inflammation of the periodontium caused by infection of the pulp canal system. Moreover, a dental periradicular lesion occurs as a periradicular tissue reaction to bacterial infection and consists of periradicular inflammation with alveolar bone destruction and root resorption, a consequence of the interaction between oral flora and the existing host defenses. Many investigations dealing with the pathogenesis and history of periradicular lesions have described histologically, immunologically, biochemically the development of the periradicular lesion；but none of these studies have shown any correlation between this lesion and several factors, the whole body disease in the worldwide.(omitted)

• Restorative Dentistry and Endodontics
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• 제44권3호
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• pp.30.1-30.6
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• 2019

We report the surgical endodontic treatment of a maxillary first premolar with a lateral lesion that originated from an accessory canal. Although lesions originating from accessory canals frequently heal with simple conventional endodontic therapy, some lesions may need additional and different treatment. In the present case, conventional root canal retreatment led to incomplete healing with the need for further treatment (i.e., surgery). Surgical endodontic management with a fast-setting calcium silicate cement was performed on the accessory canal using a dental operating microscope. At the patient's 9-month recall visit, the lesion was resolved upon radiography.

• Restorative Dentistry and Endodontics
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• 제21권1호
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• pp.150-160
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• 1996

The present study was to evaluate the accuracy of the frequency dependent type apex locator, Root-ZX. The subjects included 505 root canals of 238 teeth treated by the Department of Conservative Dentistry, and 22 human premolars which were schduled to be extracted for the orthodontic reasons. The results were as follows ; 1. The working lengths determined by Root-ZX were compared with radiographic readings. Of the total 505 root canals, 66 % showed coincidence within ${\pm}0.5mm$ and the average readings of Root-ZX were $0.13mm{\pm}1.05$ longer than those of radiographic readings. 2. The length difference between the file tip determined by Root-ZX and the apical constriction in extracted teeth were measured. Of the total 24 root canals, 70.8 % showed coincidence within ${\pm}0.5mm$ and the average readings of Root-ZX were $0.12mm{\pm}0.50$beyond the apical constriction. 3. The vitality of the teeth did not show any statistical difference(p>0.05) in the accuracy of the Root-ZX readings. The presence of the periapical lesions, however, significantly lowered the percentage of ${\pm}0.5mm$ accuracy in Root-ZX measurements.(p<0.05). In the presence of periapical lesions, the percentage within ${\pm}0.5mm$ was significantly lower.

• Restorative Dentistry and Endodontics
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• 제2권1호
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• pp.20-26
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• 1976

Cellulose acetate electrophoresis was used for differential diagnosis of radicular cysts and granulomas. Sixteen periapical lesions were excised from sixteen teeth with radiographic evidence of periapical pathosis, and two normal periodontal tissues were surgically removed from two wisdom teeth. The tissue samples were separated into two parts. Half was prepared for cellulose acetate electrophoresis, and the electrophoretic patterns were scanned with Helena densitometer. The other half was examined histologically, and the histologic diagnoses were then compared with the electrophoretic patterns and with the x-ray findings. The results were the following: 1. The histopathologic results showed the presence of 13 granulomas (81.8%) and 3 cysts (18.3%). 2. An albumin pattern, alpha-globulin pattern, beta-globulin pattern, fibrinogen pattern and gamma-globulin pattern were found in all eighteen cases. 3. All eighteen cases were divided into normal periodontal tissue group, dental granuloma group, and radicular cyst group by the histopathologic diagnosis. The electrophoretic pattern of dental granuloma group and that of normal periodontal tissue group resembled each other. The two groups showed the highest percentage in beta-globulin fraction, and the beta-globulin of dental granuloma group(47.17%) was higher than that of normal periodontal tissue group (40.54%) by 6.63%. On the contrary, beta-globulin fraction of radicular cyst group (28.00%) was much lower than those of the granuloma group (47.17%) and normal periodontal tissue group (40.54%), and alpha-globulin of radicular cyst group (34.16%) was much higher than those of the granuloma group (20.04%) and normal group (19.58%). 4. Five cases (31.3%) of the sixteen periodontal lesions showed different results between histopathologic diagnoses and radiographic findings.

• Restorative Dentistry and Endodontics
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• 제28권4호
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• pp.303-313
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• 2003

It has been documented that periodontopathic bacteria are also implicated in endodontic infections. 168 rDNA gene-directed PCR was to examine the prevalence of periodontopathic bacteria including Actinobacillus actinomycetemcomitans (Aa), Prevotella intermedia (Pi), Prevotella nigrescens (Pn), Porphyromonas gingivalis (Pg), Porphyromonas endodontalis (Pe), and Treponema denticola (Td) in the root canals of 36 endodontically infected teeth having apical lesions with or without clinical symptoms like pain, swelling, and fistula. 1. In 36 infected root canals, most frequently detected bacterial species was Pg (61.1%), followed by Td (52.8%) and Pe (38.9%). 2. Of 36 infected root canals, Aa was detected in 6 canals (16.7%) of the teeth, all of which showed clinical symptoms. 3. Of 36 infected root canals, Pi and Pn were found in 4 03.9%) and 5 (33.3%), respectively. Notably, prevalence of Pn in the symptomatic teeth was 50.0%. 4. One of black-pigmented anaerobic bacteria (BPB) including Pi, Pn, Pe, and Pg was detected in all of the teeth that showed pain or especially swelling but not fistula. It was, however, found that prevalence of BPB in the asymptomatic teeth or the teeth with fistula was only 40%. 5. Pe and Pg were detected in the teeth regardless of the presence or absence of symptoms. 6. Td was detected in the teeth regardless of the presence or absence of symptoms. High prevalence of BPB in the symptomatic teeth but low in the asymptomatic teeth suggests that BPB may play an important role in the pathogenesis of periapical lesions.

• Imaging Science in Dentistry
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• 제45권3호
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• pp.153-158
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• 2015

Purpose: The purpose of this study was to evaluate and compare the efficacy of cone-beam computed tomography (CBCT) and digital intraoral radiography in diagnosing simulated small external root resorption cavities. Materials and Methods: Cavities were drilled in 159 roots using a small spherical bur at different root levels and on all surfaces. The teeth were imaged both with intraoral digital radiography using image plates and with CBCT. Two sets of intraoral images were acquired per tooth: orthogonal (PA) which was the conventional periapical radiograph and mesioangulated (SET). Four readers were asked to rate their confidence level in detecting and locating the lesions. Receiver operating characteristic (ROC) analysis was performed to assess the accuracy of each modality in detecting the presence of lesions, the affected surface, and the affected level. Analysis of variation was used to compare the results and kappa analysis was used to evaluate interobserver agreement. Results: A significant difference in the area under the ROC curves was found among the three modalities (P=0.0002), with CBCT (0.81) having a significantly higher value than PA (0.71) or SET (0.71). PA was slightly more accurate than SET, but the difference was not statistically significant. CBCT was also superior in locating the affected surface and level. Conclusion: CBCT has already proven its superiority in detecting multiple dental conditions, and this study shows it to likewise be superior in detecting and locating incipient external root resorption.

• Imaging Science in Dentistry
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• 제52권4호
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• pp.351-357
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• 2022

Purpose: Convolutional neural networks (CNNs) have rapidly emerged as one of the most promising artificial intelligence methods in the field of medical and dental research. CNNs can provide an effective diagnostic methodology allowing for the detection of early-staged diseases. Therefore, this study aimed to evaluate the performance of a deep CNN algorithm for apical lesion segmentation from panoramic radiographs. Materials and Methods: A total of 1000 panoramic images showing apical lesions were separated into training (n=800, 80%), validation (n=100, 10%), and test (n=100, 10%) datasets. The performance of identifying apical lesions was evaluated by calculating the precision, recall, and F1-score. Results: In the test group of 180 apical lesions, 147 lesions were segmented from panoramic radiographs with an intersection over union (IoU) threshold of 0.3. The F1-score values, as a measure of performance, were 0.828, 0.815, and 0.742, respectively, with IoU thresholds of 0.3, 0.4, and 0.5. Conclusion: This study showed the potential utility of a deep learning-guided approach for the segmentation of apical lesions. The deep CNN algorithm using U-Net demonstrated considerably high performance in detecting apical lesions.

• 치과방사선
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• 제28권2호
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• pp.461-470
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• 1998

The comparative detectability of the artificial periapical defects among Ektaspeed Plus film. digitized and digora images was evaluated. The artifical defects were made in the cancellous bone and cancellous-cortical junction with the size of 1.0×0.8mm², 1.4×1.1mm² and 2.8×2.2mm². The defects in cancellous-cortical junction extended into cortical bone with the depth of 0, 0.5 and 1.0 mm. The results were as follows : 1. In junctional defects Ektaspeed Plus film for 2.8×12.2mm² defect showed the highest detectability. But significant difference were only found between Ektaspeed Plus films and digitized images (p<0.05). 2. Almost all defects within cacellous bone were not detected except a few digitized and Digora images for the size of 2.8×2.2mm². Digora images for them showed significant differences with Ektaspeed Plus films and digitized images (p<0.05). 3. The sensitinity of all imaging modalities were 0.9 or 1.0 in junctional defects for the size of 1.4×2.2mm² and 2.8×2.2mm². For cancellous defects, Digora image showed the highest sensitivity of 0.6 for the size of 2.8×2.2mm². 4. Significant differences for change of exposure time were found in most group of Ektaspeed Plus films and digitized images (p<0.05) . But there was no significant differences in Digora images for cacellous defects.