• Journal of Periodontal and Implant Science
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• v.26 no.2
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• pp.350-355
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• 1996

The present study was performed to evaluate the amount of bony regeneration following the guided tissue regeneration(GTR). Re-entry procedure has been performed at 1 year following the GTR with Gore-tex membranes on the furcal defects and the amount of bony regeneration was measured. Sites treatedwith open flap procedures were used as controls. The results reveated that significant amount of bone could be regenerated through the GTR procedures compared with convention flap procedures.

• Imaging Science in Dentistry
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• v.33 no.2
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• pp.71-77
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• 2003

Purpose : To evaluate and compare the efficacy of digital radiographic images in the detection of bone loss at the bifurcation area of the mandibular first molar with traditional film-based periapical radiographs, Materials and Methods : One dried human mandible with minimal periodontal bone loss around the first molar was selected and an artificial alveolar bone defect at the bifurcation area was serially prepared over 18 steps. Images were taken using a direct CCD-based system and with F-speed periapical films. The images were evaluated by seven interpreters (3 radiologists, 3 periodontologists, and 1 general dentist) using a 5-point confidence rating scale. Results : The readability of both periapical radiographs and digital image increased as the size of the artificial lesion and exposure time increased (p < 0.05). Periapical radiographs offered greater readability of smaller bone defects than digital images, and the coefficient of variation of mean score between periapical radiographs and digital images showed a significant difference. Conclusion : The experimental results indicate that a significant difference in the coefficient of variation of mean score exists between periapical radiographs and digital images, and that traditional film-based periapical images offer greater readability of smaller bone defects than digital images can presently offer.

• Journal of Periodontal and Implant Science
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• v.26 no.2
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• pp.356-364
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• 1996

The present study was done to evaluate the antibacterial effects of $Minoclin^R$ which was localally delivered on the $Gore-tex^R$ barrier membrane in the guided tissue regeneration(GTR) therapy for treatment of human furcal defects. Beneath the membranes. the antibiotics were applied for 1 week and then changed with new one. The $Minoclin^R$ was removed out one week later. 6 weeks after the GTR therapy. No systemic antibiotics were administered except for oral mouthrinses with chlorhexidines. 2 weeks and 6 weeks following the membrane therapy, the bacterial samples were examined for periodontopathic microorganisms. The results indicated that the locally delivered $Minoclin^R$ successfully inhibited the growth of periodontopathic organisms. This results might be further applied in the subgingival plaque control regimen in the GTR procedure, especialy in patients who is contraindicated for oral administration of systemic antibiotics

• Animal Systematics, Evolution and Diversity
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• v.17 no.1
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• pp.1-11
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• 2001

Conthocamptus mirabilis Sterba is redescribed on the basis of the material newly collected from the type locality near Bekijing, China, with an evaluation of the variability of several characters. C. mirabilis possesses the plesiomorphic characters of the round and narrow hyaline membrane and the unmodified outer terminal furcal setae, while it also bears the apomorphic ones of the male-type caudal rami in females and the modified outer terminal setae of male leg 4 exopod. the peculiar dorsal keel ornamented with spinule array on the female's caudal rami is the most significant feature differentiating this species from its relatives of the mirabilis group, which turned out to be a species group of closely related and largely allopatric or parapatric species. Affinities with the allies of the species group are discussed, and the morphological discrepancies differentiating the Japanese population are enumerated.

• Journal of Periodontal and Implant Science
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• v.26 no.1
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• pp.80-88
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• 1996

The aim of the present investigation was to see the effect of combined use of PDGF BB and IGF -1 on the guided tissue regeneration(GTR) using barrier membrane in the treatment of human furcation involvement. Twelve patients with initially diagnosed as having moderate to advanced adult periodontitis with mandibular class II buccal furcation defects have been wer selected. Initial scaling and root planing has been performed and baseline data consisting of probing depths and attachment levels have been recorded prior to surgical procedures. The GTR procedures using either barrier membrane(control : ePTFE) alone or together with the application of PDGF - BB and IGF -l(experimental : ePTFE+PDGF/IGF) have been done under the routine guidelines. During the surgery, the distance from CEJ either to the bottom of the bone defects(CEJ - BD) or to the bone crest(CEJ-BC) were measured. Horizontal distance to the deepest area in the furcal defects were measured from the reference line connection the most prominent bony walls of the two buccal roots. 6 months following the GTR therapy, all the measurements were made repeatedly. The probing attachment gain of the experimental and the control grous were 2.14mm and l.07mm, respectively with no statically significnant difference. Amont of vertical bone fill in the experimental and the control groups were 2.43mm and 2.29mm, rexpectively. Amonut of horizontal bone fill were 2.86mm in the experimental group and 2.17mm in the control group, respectively. However, there were no significant differences in the amount of bone fill(both vertical and horizontal)between the two groups.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.25 no.2
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• pp.363-373
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• 1995

The aim of this study was to evaluate and compare observer performance between conventional radiographs and their digitized images for the detection of bone loss in the bifurcation of mandiblar first molar. One dried human mandible with minimal periodontal bone loss around the first molar was selected and serially enlarged 17 step defects were prepared in the bifurcation area. The mandible was radiographed with exposure time of 0.12, 0.20, 0.25, 0.32, 0.40, 0.64 seconds, after each successive step in the preperation and all radiographs were digitized with IBM-PC/32 bit-Dx compatible, video camera (VM-S8200, Hitachi Co., Japan), and color monitor(Multisync 3D, NEC, Japan). Sylvia Image Capture Board for the ADC(analog to digital converter) was used. The obtained results were as follows: 1. In the conventional radiographs, the mean score of the readability was higher at the condition of exposure time with 0.32 second. Also, as the size of artificial lesion was increased, the readability of radiographs was elevated (P<0.05). 2. In the digital images, the mean score of the readability was higher at the condition of exposure time with 0.40 second. Also, as the size of artificial lesion was increased, the readability of digital images was elevated(P<0.05). 3. At the same exposure time, the mean scores of readibility were mostly higher in the digitized images. As the exposure time was increased, the digital images were superior to radiographs in readability. 4. As the size of lesion was changed, the digital images were superior to radiographs in detecting small lesion. 5. The coefficient of variation of mean score has no significant difference between digital images and radiographs.

• Journal of Periodontal and Implant Science
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• v.31 no.2
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• pp.269-276
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• 2001

The purpose of this study was to evaluate the clinical validity of multi-rooted teeth subjected to root-resection treatment. Over a period of 1-7 years, 60 root-resected molars in 59 patients were examined clinically and radiographically. All patients were p0eriodically recalled once or twice a year. Root-resections were due to periodontal, more specifically furcal bone loss or marginal bone loss,in 34 cases and extensive dental carious destruction in 10 cases. In other cases,root-resections resulted from 6 cases of root fracture, 6 cases of periodontal-endodontic combined lesion, and 1 case of endodontic problem. Root-resection was carried out on 26 maxillary molars and 34 mandibular molars. The results are as follows; 1. 14 cases(23.3%) were considered failures. 8 cases(13.3%) of them occurred within the first year(8 cases, 13.3%), 4 cases(6.7%)between 1-3 years, and 2 cases(3.3%) between 4-7 years. 2. 8 cases(13.3%) were considered failures due to periodontal reasons, 3 cases(5%) due to root fracture, 2 cases(3.3%) due to endodontic problem, and 1 case(1.7%) due to prosthetic problem. 3. 37 cases(61.7%) showed up for the recall appointments, and the percentage of failures(13.5%) was lower compared with that of all patients(23.3%). The results of the present study indicate that the prognosis of root-resected teeth is favourable if attention is paid to the selection of proper case and to achieving optimal oral hygiene and periodic check up.

• Journal of the korean academy of Pediatric Dentistry
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• v.32 no.4
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• pp.628-633
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• 2005

Deep caries in primary molars without early intervention frequently induce a pulpal disease and consequent furcation lesion with fistulous openings Up to now, majority of the textbooks on pediatric dentistry and literatures have described that extraction of the inflicted teeth is indicated for these cases and in reality these teeth have usually been extracted in the dental clinics. However when we recognize the excellent capacity of bone regeneration in children and the presence of numerous accessory canals at furcation areas, the removal of infection source in pulp by pulpectomy and inflammatory granulation tissues at furcation areas by furcal curettage might open the possibility of rapid healing at the furcation regions. In this report, 10 cases of primary molars in 3 to 6-year-old children with fistulous openings and furcation lesions in moderate size of 2 to 4mm in depth radiolucency at furcation lesion have been chosen. After pulpectomy and furcal curettage, evident bone regeneration was detected radiographically in all cases. Through the cases, we came to realize that all the cases previously described are not the indications of extraction and this approach could make many cases with pulp and furca combined lesions survive and remain healthy in the children's dental arches. However, in order for this approach to acquire objective appropriateness, it is thought that more scrupulous evaluation is desirable on the various factors regarding the indication such as the extent of furcation lesions, absorption status of teeth, amount of covering bone on succeeding teeth and so on.

• Restorative Dentistry and Endodontics
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• v.29 no.5
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• pp.446-453
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• 2004

The aim of this study was to evaluate the shaping abilities of four different rotary nickel-titanium instruments with anticurvature motion to prepare root canal at danger zone by measuring the change of dentin thickness in order to have techniques of safe preparation of canals with nickel-titanium files. Mesiobuccal and mesiolingual canals of forty mesial roots of extracted human lower molars were instrumented using the crown-down technique with ProFile, $GT^{TM}$ Rotary file, Quantec file and $ProTaper^{TM}$. In each root, one canal was prepared with a straight up-and-down motion and the other canal was with an anticurvature motion. Canals were instrumented until apical foramens were up to size of 30 by one operator. The muffle system was used to evaluate the root canal preparation. After superimposing the pre- and post-instrumentation canal. change in root dentin thickness was measured at the inner and outer sides of the canal at 1. 3, and 5 mm levels from the furcation. Data were analyzed using two-way ANOVA. Root dentin thickness at danger zone was significantly thinner than that at safe zone at all levels (p < 0.05). There was no significant difference in the change of root dentin thickness between the straight up-and-down and the anticurvature motions at both danger and safe zones in all groups (p > 0.05). ProTaper removed significantly more dentin than other files especially at furcal 3 mm level of danger and safe zones (p < 0.05) Therefore, it was concluded that anticurvature motion with nickel-titanium rotary instruments does not seem to be effective in danger zone of lower molars.

• Journal of dental hygiene science
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• v.16 no.4
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• pp.317-322
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• 2016

Mineral trioxide aggregate (MTA) is widely used in endodontic therapy as a pulp-capping material, root or furcal perforation repair material, and for apexification and obturation of the root canal system. The purpose of this study was to formally document cases of MTA application in South Korean children and adolescents. Through this research, the practice of using MTA will be introduced and familiarized to the clinical practitioners. This study involved endodontic treatment using MTA for fractured crowns in 11- and 12-year-old. The children were followed up for 12 months until the pulp vitality was confirmed; in young permanent teeth with immature roots, the pulp is integral to the process of apexogenesis. These observational results regarding the use of MTA as an apexification material in non-vital immature permanent incisors appear to provide promising results in the search for new materials to meet existing endodontic needs.