• Proceedings of the Korean Society of Veterinary Clinics Conference
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• 2006.05a
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• pp.210-210
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• 2006

• The Journal of Korean Academy of Prosthodontics
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• v.39 no.6
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• pp.633-640
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• 2001

Statement of problem. Relatively low success rate of root analogue implant system was supposed to be due to the time duration between extraction and implant installation. The use of three-dimensional computer tomography and the reconstruction of objects using rapid prototyping methods would be helpful to shorten this time. Purpose. This aim of this study was to evaluate the application possibility of the 3-dimensional computer tomography and the rapid prototyping to root analogue implants. Material and methods. Ten single rooted teeth were prepared. Width and height of the teeth were measured by the marking points. This was followed by CT scanning, data conversion and rapid prototyping model fabrication. 2 methods were used; fused deposition modelling and stereolithography. Same width and height of this models were measured and compared to the original tooth. Results. Fused deposition modelling showed an enlarged width and reduced height. The stereolithography showed more exact data compared with the fused deposition modelling. Smaller standard deviation were recorded in the stereolithographic method. Overall width error from tooth to rapid prototyping was 7.15% in fused deposition modelling and 0.2% in stereolithography. Overall height showed the tendency of reducing dimensions. Conclusion. From the results of this study, stereolithography seems to be very predictable method of fabricating root analogue implant.

• Computers and Concrete
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• v.31 no.2
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• pp.163-171
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• 2023

Face gear transmission is widely used in aerospace shunt-confluence transmission system. Tooth wear is one of the main factors affecting its bearing transmission performance. Furthermore, the installation errors of face gear are inevitable. In order to study the wear mechanism of face gear tooth surface with installation errors, based on tooth contact analysis numerical method and Archard wear theory, the UMESHMOTION subroutine in ABAQUS is developed.Combining with Arbitrary Lagrangian-Eulerian adaptive mesh technology, the finite element mesh wear model of abraded face gear pair is established.The preprocessing conditions are set to generate the inp files.Then,the inp files for each corner are imported and batch processed in ABAQUS.The loading tooth contact problem at each rotation angle is solved and the load distribution coefficient among gear tooth, tooth root bending stress, tooth surface contact stress and loaded transmission error are obtained. Results show that the tooth root wear is the most serious and the wear at the pitch cone is close to 0.The wear law of tooth surface along tooth width direction is convex parabola and the wear law along tooth height direction is concave parabola.

• The Journal of the Korean dental association
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• v.54 no.8
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• pp.658-665
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• 2016

Treatment of immature permanent teeth with irreversibly damaged pulp has been challenging in dental practice because of the lack of apical constriction, thin dentinal walls, and short roots. This may lead to the extrusion of filling materials, and fracture of the root due to its more fragile feature during shaping of the root canal. Apexification with calcium hydroxide or MTA is one of the treatment options for these cases. Although favorable results of apexification have been reported, these treatment procedures do not guarantee the increase of root length and/or width even after a long term period. Thus, treated teeth are still prone to fractures. Recently, pulp revascularization has been proposed as an alternative treatment for immature teeth with necrotic pulp and periapical pathosis. Pulp revascularization allows the stimulation of the apical development and the root maturation. There have been many treatment protocols using various materials such as antibiotics and calcium hydroxide medicament. In this case report, literature review about pulp revascularization and two related cases are presented.

• Restorative Dentistry and Endodontics
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• v.39 no.3
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• pp.226-229
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• 2014

Orthodontic extrusion is usually performed by means of a fixed orthodontic appliance that utilizes arch wire attached to adjacent teeth and transfers the desired force by elastic from the wire to the root. However, clinicians often encounter cases where the bonding required for tooth traction is not possible because the adjacent teeth have been restored with ceramic or veneer. The purpose of this case report is to describe a modified orthodontic extrusion appliance that is useful when conventional orthodontic treatment is not possible. The modified appliance was fabricated using an artificial tooth, clear plastic sheeting, and a braided fiber-reinforced composite strip that covered adjacent teeth without bonding. It satisfied the esthetic and functional needs of the patient and established the optimal biologic width.

• Restorative Dentistry and Endodontics
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• v.41 no.3
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• pp.210-217
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• 2016

Exposing sound structure of a subgingivally fractured tooth using orthodontic extrusion is considered to be a conservative way to re-establish biologic width without sacrificing esthetics or jeopardizing periodontal support of neighboring teeth. When a misaligned tooth is traumatically involved, a more comprehensive approach combining tooth extrusion and re-alignment may be necessary for a successful restorative outcome. This case report describes a successful esthetic management of a patient with complicated crown-root fracture on the maxillary right central incisor and pre-existing malocclusion in the maxillary anterior region. Forced eruption along with re-alignment of teeth by orthodontic movement seems to allow re-positioning of the fracture line to a favorable position and correction of crowding, providing a better esthetic result.

• Journal of the korean academy of Pediatric Dentistry
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• v.35 no.2
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• pp.305-312
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• 2008

Crown-root fractures occur throughout both crown and root, and are defined as fractures involving enamel, dentin and cementum. The fractures may be grouped according to pulpal involvement into complicated and uncomplicated one. Crown-root fractures often occur on maxillary anterior teeth and comprise 5% of injuries affecting the permanent dentition and 2% in the primary dentition. To restore crown-root fractured tooth, biologic width must be maintained. For maintaining biologic width, such methods as gingivectomy following osteoplasty or orthodontic extrusion or surgical extrusion are available. Surgical extrusion is a method that extracts the tooth and replants the fractured tooth supragingivally. It is indicated when the length of the crown fragment is less than half the length of the clinical root. In these cases, root canal treatment and crown restoration using light-cured composite resin were performed after surgical extrusion. In following periodic examinations, favorable outcome was observed.

• The korean journal of orthodontics
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• v.38 no.4
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• pp.265-274
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• 2008

Objective: The aim of this study was to evaluate the potency of panoramic radiography for the detection of maxillary impacted canines. Methods: Twenty-five patients were selected, comprised of 7 males (mean age: 10.9 years, range: 8.5 - 14.5 years) and 18 females (mean age: 10.9 years, range: 8.2 - 15.7 years). In total, thirty-five maxillary impacted canines were estimated. The position of the canine and root resorption of adjacent teeth were evaluated on panoramic radiography and 3D CT. Results: Except for angulation to the occlusal plane, the other parameters, such as tooth length, crown width, vertical distance and lateral shift showed larger values on panoramic radiography compared to 3D CT. In palatally impacted cases, the angulation of canine was smaller, and the vertical distance to the occlusal place was larger on panoramic radiography than 3D CT. For labially impacted canines, tooth length, crown width, and angulation to the occlusal plane were similar for the two methods. The sensitivity for detecting root resorption on panoramic radiography was calculated as being 33.3% of 3D CT. Conclusions: The position of labially impacted canines can be effectively estimated using panoramic radiography, but palatally impacted canines need further investigation such as 3D CT for proper diagnosis.

• Journal of Dental Rehabilitation and Applied Science
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• v.24 no.3
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• pp.243-251
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• 2008

A subgingival crown-root fracture presents a restorative problem to the clinician because restoration is complicated by the need to maintain the sound tooth structures. Forced eruption offers a method of treatment of teeth fractured close to the alveolar crest. Extrusion of such teeth allows elevating the fracture line above the epitherial attachment and so the proper finishing margins can be prepared. The purpose of this case is to report successful tooth restoration using forced eruption in case of crown-root fractures.

• Imaging Science in Dentistry
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• v.44 no.4
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• pp.287-292
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• 2014

Purpose: To describe the features of impacted upper canines and their relationship with adjacent structures through three-dimensional cone-beam computed tomography (CBCT) images. Materials and Methods: Using the CBCT scans of 79 upper impacted canines, we evaluated the following parameters: gender, unilateral/bilateral occurrence, location, presence and degree of root resorption of adjacent teeth (mild, moderate, or severe), root dilaceration, dental follicle width, and presence of other associated local conditions. Results: Most of the impacted canines were observed in females (56 cases), unilaterally (51 cases), and at a palatine location (53 cases). Root resorption in adjacent teeth and root dilaceration were observed in 55 and 47 impacted canines, respectively. In most of the cases, the width of the dental follicle of the canine was normal; it was abnormally wide in 20 cases. A statistically significant association was observed for all variables, except for root dilaceration (p=0.115) and the side of impaction (p=0.260). Conclusion: Root resorption of adjacent teeth was present in most cases of canine impaction, mostly affecting adjacent lateral incisors to a mild degree. A wide dental follicle of impacted canines was not associated with a higher incidence of external root resorption of adjacent teeth.