• The Journal of Advanced Prosthodontics
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• v.6 no.6
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• pp.528-538
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• 2014

PURPOSE. The purpose of this prospective study was to evaluate the effectiveness of newly developed autogenous tooth bone graft material (AutoBT)application for sinus bone graft procedure. MATERIALS AND METHODS. The patients with less than 5.0 mm of residual bone height in maxillary posterior area were enrolled. For the sinus bone graft procedure, Bio-Oss was grafted in control group and AutoBT powder was grafted in experimental group. Clinical and radiographic examination were done for the comparison of grafted materials in sinus cavity between groups. At 4 months after sinus bone graft procedure, biopsy specimens were analyzed by microcomputed tomography and histomorphometric examination for the evaluation of healing state of bone graft site. RESULTS. In CT evaluation, there was no difference in bone density, bone height and sinus membrane thickness between groups. In microCT analysis, there was no difference in total bone volume, new bone volume, bone mineral density of new bone between groups. There was significant difference trabecular thickness ($0.07{\mu}m$ in Bio-Oss group Vs. $0.08{\mu}m$ in AutoBT group) (P=.006). In histomorphometric analysis, there was no difference in new bone formation, residual graft material, bone marrow space between groups. There was significant difference osteoid thickness ($8.35{\mu}m$ in Bio-Oss group Vs. $13.12{\mu}m$ in AutoBT group) (P=.025). CONCLUSION. AutoBT could be considered a viable alternative to the autogenous bone or other bone graft materials in sinus bone graft procedure.

• Journal of Korean Dental Science
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• v.9 no.2
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• pp.55-62
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• 2016

Purpose: Alveolar bone develops with tooth eruption and is absorbed following tooth extraction. Various ridge preservation techniques have sought to prevent ridge atrophy, with no superior technique evident. Collagen has a long history as a biocompatible material. Its usefulness and safety have been amply verified. The related compound, atelocollagen, is also safe and displays reduced antigenicity since telopeptides are not present. Materials and Methods: The current study evaluated whether the $Rapiderm^{(R)}$ atelocollagen plug (Dalim Tissen, Seoul, Korea) improves tissue healing of extraction sockets and assessed the sequential pattern of bone regeneration using histology and microcomputed tomography in six beagle dogs. To assess the change of extraction socket, hard tissues were examined 2, 4, 6, and 8 weeks after tooth extraction. Result: The experimental groups showed better bone fill with slow remodeling process compared to the control groups although there was no statistical difference between groups. Conclusion: The atelocollagen seems to have a tendency to slow bone remodeling in the early phase of healing period and maintain remodeling capacity until late phase of remodeling. Also, use of atelocollagen increased the bone-to-tissue ratio compared to healing of untreated extraction socket.

• Journal of Periodontal and Implant Science
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• v.38 no.4
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• pp.611-620
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• 2008

Purpose: The purpose of this study was to assess the long term survival rates of the most posterior single tooth implant and to evaluate the influence of implant characteristics on implant survival. Material and Methods: This retrospective report presents findings on 37 patients with 43 implants replacing single molars. The inclusion criteria were having implants replacing a molar of the most posterior region and follow-up data over at least 6 months. Data were recorded regarding the incidence of complications and survival rates of these implants. Results: The range of follow-up was from 9 to 66 months(mean: 40.2 months). The cumulative survival rate of total implants was 93.0% which reflects the loss of three implants: one had broken neck, one implant failed because of infection, one implant showed failed osseointegration. Abutment- screws loosening occurred in five implants(11.6%). Conclusion: Within the limits of this study, a single tooth-implant can serve as a good long-term and predictable treatment modality to replace the most posterior teeth with low complication and failure rates.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.9
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• pp.1914-1922
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• 2002

Operating test of power-transmission plastic spur gears were performed inspecting both characteristics of friction-wear and endurance, and suggesting endurance improvement method that either drills internal holes of tooth or inserts metallic pin in the internal hole of tooth and verifying this newly-provided method. In case of acetal gears, amount of friction-wear is observed to increase by development of plastic deformation and increase of tooth stiffness due to brittle material property of acetal. To the contrary, in case of nylon gears, suggested method is shown to drop down the tooth temperature for about 3∼10$^{\circ}C$ than original gear, thus amount of wear is reduced by over 30% and operating lift prolonged by more than 200%. Hence, suggested method is proved to be practically applicable to the plastic gears made by soft polymers such as Nylon.

• The Journal of Korea Assosiation for Disability and Oral Health
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• v.14 no.1
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• pp.26-30
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• 2018

Aspiration of tooth can occur not only during dental treatment, but also due to factors like trauma or physiologic exfoliation of primary tooth. If this occurs, complications such as fever, cough, dyspnea, pain, and bronchitis can be appeared. 9 years-old girl with Lennox-Gastau syndrome visited the dental clinic for regular checkups. Calcified tooth-like material was observed in the chest PA x-ray, and maxillary left primary first molar was not observed in the patient's oral cavity. She had a history of hospitalization for pneumonia two months ago. Because it was considered that the tooth was likely to be aspirated and caused pneumonia, the extraction of remaining primary teeth with mobility was performed. It is necessary to reduce the risk of aspiration in patient with disabilities by performing active treatment such as removal of primary tooth with mobility or ill-fitting restorations.

• Restorative Dentistry and Endodontics
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• v.12 no.1
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• pp.85-93
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• 1986

The purpose of this study was to investigate the curing effect of visible light through tooth substance, 0.5mm, 1.0mm thickness of enamel and dentin were prepared. Experimental specimen were made by Bisfil M & Silux packing into cylindrical brass mold 6.0mm in diameter, 2.0mm and 3.0mm, in height. All specimen were irradiated by visible light (Grip type) model No. SDL-50 Shofu Co.) for 30 seconds through tooth substance. Experimental groups were classified into enamel group (group 1) and dentin group (group 2) according to the thickness of tooth materials and then were divided into 2 subgroups (0.5mm group and 1.0mm group). In experimental groups, visible light irradiated to the specimen through either 0.5mm in thick or 1.0mm in think of tooth material. In Control group specimen were prepared by direct irradiation on the specimen surface of visible light without through tooth substance. The hardness was measured with a Barcol hardness tester (Barber-Colman Co. U.S.A.) for each prepared specimen. The results were as follows: 1. In control group, there were higher hardness values than those of in experimental group. 2. In experimental groups, 0.5mm groups had higher hardness values than 1.0mm groups did. 3. The hardness value at top surface of the specimen were higher than the hardness of bottom surface in each group. 4. Bisfil M had higher hardness values than Silux. 5. In all specimen of 3.0mm height polymerization effect was not occurred at bottom surface except Bisfil M in control group.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.37
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• pp.2.1-2.9
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• 2015

Background: The aim of this study was to evaluate the effect of autogenous tooth bone as a graft material for regeneration of bone in vertical bony defects of the minipigs. Material and Methods: Six minipigs were used in this study. Four molars were extracted in the right mandibular dentition and sent to the Korea Tooth Bank for fabrication of autogenous tooth bone. Ten days later, each extraction site was implanted with MS Implant Narrow Ridge $3.0{\times}10mm$ fixture (Osstem, Seoul, Korea) after standardized 2mm-sized artificial vertical bony defect formation. Pineappleshaped Root-On type autogenous tooth bones were applied to the vertical defects around the neck area of the posterior three fixtures and the fore-most one was not applied with autogenous bone as a control group. Each minipig was sacrificed at 4, 8, 12 weeks after fixture installation and examined radiologically and histologically. Histological evaluation was done under light microscope with Villanueva osteochrome bone staining with semi-quantitative histomorphometric study. Percentage of new bone over total area (NBF) and bone to implant contact (BIC) ratio were evaluated using digital software for area calculation. Result: NBF were $48.15{\pm}18.02%$, $45.50{\pm}28.37%$, and $77.13{\pm}15.30%$ in 4, 8, and 12 weeks, respectively for experimental groups. The control group showed $37.00{\pm}11.53%$, $32.25{\pm}26.99%$, and $1.33{\pm}2.31%$ in 4,8,12 weeks, respectively. BIC ratio were $53.08{\pm}19.82%$, $45.00{\pm}28.37%$, and $75.13{\pm}16.55%$ in 4,8,12 weeks, respectively. Those for the control groups were $38.33{\pm}6.43%$, $33.50{\pm}29.51%$, and $1.33{\pm}2.31%$ in 4, 8, 12 weeks, respectively. Conclusion: Autogenous tooth bone showed higher score than control group in NBF and BIC in all the data encompassing 4,8,12 weeks specimens, but statistically significant only 12 weeks data in both NBF and BIC.

• Restorative Dentistry and Endodontics
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• v.27 no.1
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• pp.16-23
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• 2002

Physical properties of composite resins such as strength, resistance to wear, discoloration, etc depend on the degree of conversion of the resin components. The purpose of this study was to evaluate the degree of conversion of the composite resins according to the thickness of tooth structure penetrated by light and applied light curing time. The coronal portions of extracted human teeth (one anterior tooth, three posterior tooth) was embedded by pink denture material. the mounted teeth were cut into three illumination sections (1mm thickness enamel section, 1mm thickness dentin section, 2mm thicknes dentin section) and one backing section with cutting wheel. Thin resin films were made by using 6kg pressure between slide glass during 5 minutes Thin resin film was light cured on coupled illumination section during 40sec, 80sec and 120sec. each illumination section was coupled as follows; no tooth structure(X), ename section(E), enamel section + 1mm dentin section(ED1), enamel section + 2mm dentin section(ED2), enamel section + 1mm dentin section + 2mm dentin section(EDD). To simulate the clinical situation more closely, thin resin films was cured against a backing section of tooth structure. The degree of conversion of carbon double bonds to single bonds in the resin films were examined by means of Fourier Transform Infrared Spectrometer. The results were obtained as follows ; 1 As curing time was increased, conversion rate was increased and as tooth thickness which was penetrated by curing light was increased, conversion rate was decreased. 2. At all tooth thickness groups, conversion rate between 80sec and 120sec was not significantly increased(P＞0.05). 3. At 40sec group and 80sec, conversion rate between no tooth structure(X) group and 1mm enamel section(E) group was not significantly decreased(P＞0.05). 4. At 80sec group and 120sec, conversion rate between 1mm enamel section(E) group and 1mm enamel section + 1mm dentin section(ED1) group was not significantly decreased(P＞0.05).

• Journal of Dental Rehabilitation and Applied Science
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• v.27 no.2
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• pp.141-147
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• 2011

The aim of this study was to evaluate histomorphometrically and compare the efficiency of various bone graft material and autogenous tooth bone graft material which were used in sinus bone graft procedure. Subjects were the 24 patients who had treated with sinus bone graft using lateral approach from October 2007 to September 2009 at SNUBH. The average age was $52.51{\pm}11.86$ years. All cases was taken after 4month of procedure and divided into 3 groups according to bone graft material. Group 1: autogenous tooth bone graft material, Group 2: OrthoblastII(integra lifescience corp. Irvine, US)+Biocera(Osscotec, seoul, korea), group 3: DBX(Synthes, USA)+BioOss(Geistlich Pharm AG, Wolhusen, Switzerland). Total 37 implant placement area were included and evaluated(7 in group 1, 10 in group 2, 20 in group 3). Evaluation of new bone formation, ratio of woven bone to lamellar bone, ratio of new bone to graft material were performed on each tissue section. Kruskal-Wallis test was used for statistical analysis(SPSS Ver. 12.0, USA). New bone formation were $52.5{\pm}10.7%$ in group 1, $52.0{\pm}23.4%$ in group 2, $51.0{\pm}18.3%$ in group 3. There were no statistical significant differences between each groups. Ratio of woven bone to lamella bone were $82.8{\pm}15.3%$ in group 1, $36.7{\pm}59.3%$ in group 2, $31.0{\pm} 51.2%$ in group 3. Ratio of new bone to graft material were $81.3{\pm}10.4%$ in group 1, $72.5{\pm}28.8%$ in group 2, $80.3{\pm}24.0%$ in group 3. After 4 month of healing period, all group showed favorable new bone formation and around graft material and implant. Within limitation of our study, it is suggested that autogenous tooth bone graft material might be used as novel bone graft material for sinus bone graft.

• Imaging Science in Dentistry
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• v.44 no.1
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• pp.37-41
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• 2014

Purpose: The aim of this study was to investigate the accuracy of cone-beam computed tomography (CBCT) in the diagnosis of vertical root fractures in a tooth with gutta-percha and prefabricated posts. Materials and Methods: This study selected 96 extracted molar and premolar teeth of the mandible. These teeth were divided into six groups as follows: Groups A, B, and C consisted of teeth with vertical root fractures, and groups D, E, and F had teeth without vertical root fractures; groups A and D had teeth with gutta-percha and prefabricated posts; groups B and E had teeth with gutta-percha but without prefabricated posts, and groups C and F had teeth without gutta-percha or prefabricated posts. Then, the CBCT scans were obtained and examined by three oral and maxillofacial radiologists in order to determine the presence of vertical root fractures. The data were analyzed using IBM SPSS 20.0 (IBM Corp., Armonk, NY, USA). Results: The kappa coefficient was $0.875{\pm}0.049$. Groups A and D showed a sensitivity of 81% and a specificity of 100%; groups E and B, a sensitivity of 94% and a specificity of 100%; and groups C and F, a sensitivity of 88% and a specificity of 100%. Conclusion: The CBCT scans revealed a high accuracy in the diagnosis of vertical root fractures; the accuracy did not decrease in the presence of gutta-percha. The presence of prefabricated posts also had little effect on the accuracy of the system, which was, of course, not statistically significant.