• The Journal of Korean Academy of Prosthodontics
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• v.52 no.3
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• pp.252-257
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• 2014

It is important to produce a provisional restoration reflecting the patient's jaw relation, occlusal plane, lip support, shape of teeth, and occlusion type for fully edentulous patients before making a definite prosthesis. The patient introduced in this study showed bad prognosis of remained tooth after severe periodontal diseases. Therefore, remaining teeth were extracted and replaced with dental implants. Provisional restorations were fabricated and the the patient's vertical and horizontal jaw relationship, occlusal plane, amount of overjet and overbite, size of teeth, and length of anterior tooth were recorded. Provisional restorations were scanned and CAD/CAM techniques were used to fabricate a monolithic zirconia bridge, which contour is identical with the provisional restorations. The patient was satisfied with the treatment results on functional, esthetic aspects and the prosthesis retained stable during the four-month clinical observation period.

• Journal of Dental Rehabilitation and Applied Science
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• v.39 no.4
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• pp.229-236
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• 2023

Maxillary bone defects may follow surgical treatment of benign and malignant tumors, trauma, and infection. Palatal defects often lead to problems with swallowing and pronunciation from the leakage of air into the nasal cavity and sinus. Obturators have been commonly used to solve these problems, but long-term use of the device may cause irritation of the oral mucosa or damage to the abutment teeth. Utilizing implants in the edentulous area for the fabrication of the obturators has gained attention. This case report describes a patient, who had undergone partial resection of the maxilla due to adenocarcinoma, in need of a new obturator after losing abutment teeth after long-term use of the previous obturator. Implants were placed in strategic locations, and an implant-retained maxillary obturator was fabricated, showing satisfactory results in the rehabilitation of multiple aspects, including palatal defect, masticatory function, swallowing, pronunciation, and aesthetics.

• Journal of Dental Rehabilitation and Applied Science
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• v.32 no.4
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• pp.314-321
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• 2016

Conventional removable partial dentures (RPDs) with distal extensions are associated with some problems, including lack of stability that calls for frequent relining, and cantilever actions of claps that can produce excessive loading to abutment teeth, and the need for unesthetic retentive arm clasps. Therefore, IARPDs (Implant-assisted RPD) that use implants to support or retain RPDs has been reported to improve stability, esthetics and masticatory performance of RPDs. Also, an IARPD that has zirconia occlusal table can prevent the incongruity of occlusal plane and the extrusion of antagonistic tooth. In this case of partially edentulous patient with crossed occlusion, each edentulous area was restored with implant fixed prosthesis and implant retained partial denture to suit each situation. Through the procedure, satisfactory outcomes were achieved both in functional and esthetic aspects.

• Journal of Korean Dental Science
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• v.9 no.2
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• pp.63-68
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• 2016

Pressure root resorption can be observed during the eruption of permanent dentition, especially of the maxillary canines (affecting lateral incisors) and mandibular third molars (affecting mandibular second molars). Since the cause of root resorption of the adjacent affected teeth is evident, treatment simply involves extraction of the impacted tooth. However, there have been few reports on the prognosis of the remaining resorbed tooth, as dentists often choose to extract them when damage due to root resorption is observed. We report a case involving a tooth that was severely resorbed due to pressure from an adjacent impacted tooth. After extraction of the impacted tooth, the remaining tooth retained vital pulp and survived as a functional tooth.

• Journal of Advanced Marine Engineering and Technology
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• v.21 no.5
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• pp.512-521
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• 1997

This paper deals with an evaluation of the residual stress due to shot peening induced in a car¬burized gear tooth and its application to the fatigue crack propagation problem. The residual stress is estimated based on the assumption that the main cause of residual stress is the volume difference between the case and core due to martensitic transformation in cooling, and the influ¬ence of both the reduction of retained austenite and the strain in the surface layer induced by shot peening are considered. The reliability of the method is examined by comparison with stresses measured by the X-ray diffraction method. The stresses intensity factors are computed by the influence function method and the reduction of the factor due to the residual stress is demonstrat¬ed and discussed based on the fracture mechanics.

• Journal of the Korean Society of Safety
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• v.12 no.3
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• pp.30-37
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• 1997

This paper deals with the residual stress of carburized spur gears is calculated being on the assumption that the main cause of residual stress is the volume difference between case and core due to the martensitic transformation in cooling. A formula is proposed to estimated the residual stress from the hardness and the amount of retained austenite. The estimated residual stress is close to the stress measured by X-ray method. The estimated residual stress is applied to the analysis of the fracture mechanics of carburized spur gear teeth. The stress intensity factor due to the residual stress is demonstrated. The stress intensity factor is computed by the influence function method, and it is shown that the factor is decreased by the residual stress in Carburized gear tooth.

• Journal of the korean academy of Pediatric Dentistry
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• v.34 no.4
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• pp.679-684
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• 2007

Odontoma is the most common benign odontogenic tumors, and have been defined as mixed odontogenic tumor composed of epithelial and mesenchymal cells. Odontoma is believed to be hamartomatous rather than neoplastic in nature. The classification by WHO divides odontoma into 2 groups such as complex odontoma and compound odontoma. Compound odontoma comprises dental tissues, resembling the morphology of a tooth and has predilection for the anterior maxilla. In contrast, complex odontoma has unorganized mass, not resembling the normal tooth and has predilection for the posterior mandible. Odontoma is almost asymptomatic, so it is usually found on routine radiographic examination. Common presenting symptom is impacted or unerupted permanent teeth and retained primary teeth, but coexistent odontoma and congenital missing of permanent teeth is a very rare condition. The recommended treatment for an odontoma is conservative surgical excision, with care taken to remove the surrounding soft tissue. This report presents 2 patients with compound odontoma of the mandible who have congenital missing of the permanent teeth.

• The Journal of Korean Academy of Prosthodontics
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• v.59 no.2
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• pp.238-247
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• 2021

Congenital tooth agenesis is the most common developmental dental anomaly, of which oligodontia is defined as the absence of six or more permanent teeth, except the third molars. Tooth agenesis causes malocclusion, alveolar atrophy, aesthetic and psychosocial problems. This clinical report describes a multidisciplinary treatment for a patient diagnosed as oligodontia, who exhibited absence of 14 permanent teeth, atrophy of maxillary alveolar bone, and mandibular protrusion. Restoration space was secured and tooth axis was improved by the extraction of deciduous teeth and orthodontic treatment. However, edge-to-edge bite of posterior teeth and arch dimension discrepancy due to atrophic maxilla was remained. To restore the aesthetics and functionality, implant retained prosthesis was planned. Considering minimal bone grafts, location and number of dental implants and prostheses design were determined. Through the gradual adjustment of provisional restoration, the appropriate centric and eccentric occlusion was reflected into a definitive prosthesis. Currently, stable functional results were attained, however, regular follow up and maintenance care over lifetimes should be performed.

• Journal of Dental Rehabilitation and Applied Science
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• v.28 no.3
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• pp.253-268
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• 2012

Full-mouth reconstruction of a patient using dental implants is a challenge if there is vertical and horizontal bone resorption, since this includes the gingival area and restricts the position of the implants. however, hard- and soft-tissue grafting may allow the implants to be placed into the desired position. Although it is possible to regenerate lost tissues, an alternative is to use fixed detachable prostheses that restore the function and the esthetics of the gingiva and teeth. Various material combinations including metal/acrylic, metal/ceramic, and zirconia/ceramic have been used for constructing this type of restoration. Other problems include wear, separation or fracture of the resin teeth from the metal/acrylic prosthesis, chipping or fracture of porcelain from the metal/ceramic or zirconia/ceramic prosthesis, and fracture of the framework in some free-end prostheses. With virtually unbreakable, chip-proof, life-like nature, monolithic zirconia frameworks can prospectively replace other framework materials. This clinical report describes the restoration of a patient with complete fixed detachable maxillary and mandibular prostheses made of monolithic zirconia with dental implants. The occluding surfaces were made of monolithic zirconia, to decrease the risk of chipping or fracture. The prostheses were esthetically pleasing, and no clinical complications have been reported after two years.

• The Journal of Korean Academy of Prosthodontics
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• v.35 no.4
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• pp.793-800
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• 1997

Periotest(Siemens, Germany) has been used to test mobility of the implants clinically, however the effects of target materials and connection methods on the PTVs(Periotest Values) have not been evaluated. Periotest has been regarded as a reliable and objective tool to test implant and natural teeth mobility clinically, however this instrument showed different PTVs under various test conditions. This in vitro study was designed to compare PTVs of different veneering materials and prosthodontic designs (single and bridge restorations). To compare the effects of veneering materials on PTVs, 1 mm thickness of five different testing materials (porcelain, type III gold alloy, pure titanium, composite resin, acrylic resin) were placed on the resin block. Three full length of 13 mm Mark II implant fixtures were embedded into autopolymerizing resin block to fabricate single and bridge restorations. To evaluate effects of the connection method in single restorations, PTVs of screw retained(UCLA type) and cementation type(Cera-One system) were compared. Finally, to test reliability of PTVs of the final restorations, screw retained three unit short span PFM bridges were fabricated on the standard and Estheti-Cone abutments. All testing components were tightened with torque controller and PTVs of all specimens were measured 15 times for statistical analysis with SAS program. Following conclusions were made within the limit of this in vitro study. 1. PTVs of type III gold alloy, grade II titanium, composite resin veneering materials showed no significant differences, however acrylic resin and porcelain showed significant differences (P<0.05). 2. Single tooth restorations showed consistent PTVs as long as proper torque force was applied. 3. PTVs of bridge type prostheses was inconsistent regardless of abutment types. 4. PTVs of the prostheses showed higher scores and standard deviations than those of abutments regardless types of connection (P<0.05).