• The Journal of Korean Academy of Prosthodontics
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• v.55 no.3
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• pp.292-299
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• 2017

Long-term alveolar bone resorption in edentulous patient causes difficulty in denture use. Applying an implant overdenture with 2 to 4 implants to edentulous patient is easily approachable. Moreover, it improves denture stability, support, and retention. Milled bar, the attachment used in implant overdenture, can be used to induce better stability and retention to the supporting structure than conventional bar. It has become convenient to use due to the development of CAD/CAM system which had allowed the simplification of dental techniques. In this case, application of conventional maxillary full denture and mandibular overdenture made of CAD/CAM milled bar with 4 implants showed satisfactory results in the patient who had used upper and lower full dentures for a long time.

• Journal of Korea Multimedia Society
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• v.3 no.1
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• pp.63-76
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• 2000

Most work done in CSCW (Computer Supported Collaborative Work) system has been targeted toward supporting the exchange of documents or messages among group members, and yet support for cognitive aspects such as group organization, division and merge of work, and work flow control. The objective of the study is to provide CSCW environment for the engineering design process such as CAD (Computer Aided Design) and CASE (Computer Aided Software Engineering). The proposed DCWA (Distributed Collaborative Writing Aid) system suggests a mechanism that unifies the group organization, work division, and work flow control in the CAO, CASE, and software simulation tool. In particular, CAD relates the group and work partition by providing expressing the relation of drawing object (e.g., binding, attachment, and proportional scaling) which is owned by different members of group, and CASE combining with the simulation tool supports the flexibility of the work flow control. Simulating the prototype before manu-facturing a product can reduce time and cost in development.

• Journal of Power System Engineering
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• v.16 no.5
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• pp.70-75
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• 2012

In mechanical industries, forging is one of the basic process. But comparing the other developed industries, forging industries can not reach at the level of that development. In forging industries, the quality of the products totally depends on the skills of workers and also the precision of the equipments. Particularly because the open die forging industry is unable to deviate from the past method of production and all works are manually progressed, the operator is always exposed to the danger. In the regard some additional device has been made especially. Thus, in this research, by using the forklift as the means for the manipulation of the development object system, it tries to be comprised the process automation. After than it is fitted with the forklift for safe and easy handling of jobs and products during open die forging process. First of all, development system mold has been assembled to the system, after than it is assembled with forklift. This development system has been applied for handling of large scale products more than 300kg, and the satisfactory result with uniform quality of the products have been achieved due to this mechanical setup.

• The Journal of Korean Academy of Prosthodontics
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• v.33 no.1
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• pp.130-143
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• 1995

The purpose of this study was to analyze the magnitude and distribution of stress using photoelastic model with the rigid connection using T-block attachment and non-rigid connection using key & keyway attachment. The vertical load of 16 Kg was applied on the central fossa of the tooth, the pontic and the implant, and the pattern and distribution under each condition was analyzed. The following results were obtained : 1. In case of vertical load on the central fossa of the implant, the stress was concentrated at the apex of the implant involving the mesial alveolar bone in both fixed partial denture with the rigid connection and that with the nonrigid connection and the stress concentration at the mesial cervical area of the implant was a little more in the nonrigid connection than in the rigid connection. 2. In case of vertical load on the central fossa of the pontic, the stress was concentrated at the apex of 2nd bicuspid in both 3 unit fixed partial denture with nonrigid connection and that with the rigid connection. The stress was more concentrated at the mesial alveolar bone of the implant, but the stress distribution at the natural teeth more favorable at the rigid connection than at the non-rigid connection in case of 4 unit fixed partial denture. 3. In case of vertical load of the central fossa of the 2nd bicuspid, much stress with 3 fringe order was observed at the apex of the 2nd bicuspid in the 3 unit fixed partial denture, but relatively even stress distribution was observed at the apex of the implant, the 1st and 2nd bicuspid, and the adjacent cuspid in the 4 unit fixed partial denture.

• Journal of the korean academy of Pediatric Dentistry
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• v.28 no.4
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• pp.626-632
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• 2001

Ectodermal dysplasia is a hereditary disease characterized by congenital dysplasia of one or more ectodermal structures. Intraorally, common findings are anodontia or oligodontia, conical teeth, and, consequently, generalized spacing. This case presented the oral rehabilitation of a child with hypohidrotic ectodermal dysplasia. Oral rehabilitation is important from functional, esthetic, and psychologic perspectives. Due to the absence of teeth, the volume of alveolar bone and its growth are decreased, resulting in a loss of vertical dimension and protuberant lips. The treatment involved increasing the patient's vertical dimension of occlusion, fabricating a maxillary partial denture, and using magnets to help retain the mandibular partial denture. A 5-year 7-month old Korean boy was referred to the pediatric department for examination, evaluation and treatment of his disorder. we used magnets on '73 and '83 for enhanced retention of a mandibular overdenture. The magnet used in this case was the Magfit system(GC Co., Japan).

• Journal of Dental Rehabilitation and Applied Science
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• v.27 no.2
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• pp.223-231
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• 2011

The purpose of this case report is to introduce new attachment system(milled titanium bar with $Locator^{(R)}$ attachment) for implant supported overdenture in maxillary edentulous patients. A 56-years-old male patient visited the hospital due to the mobility of his maxillary fixed partial dentures(10-unit bridge). Including temporomandibular joint(TMJ), there was no specific PMHs to influence dental treatment. In radiographic and clinical evaluation, there was a severe bone resorption and mobility in maxillary teeth. Accordingly all the remaining maxillary teeth was extracted and fabrication of implant supported overdenture was planned. The milled titanium bar with $Locator^{(R)}$ was designed as an attachment system, considering the stability and retention of denture, masticatory efficiency, oral hygiene care, esthetics, pronunciation, and patient's financial state. The milled titanium bar was manufactured using CAD/CAM technology, and $Locator^{(R)}$ attachment connected to the bar by tap & drill method. For over 1-year, in terms of function and esthetics, satisfactory result was obtained.

• The Journal of Korean Academy of Prosthodontics
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• v.35 no.3
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• pp.577-608
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• 1997

The purpose of this study is to evaluate the stress distribution in the bone around dental implants supporting mandibular overdenture according to the number of implant and the type of attachment. Two or four implants were placed in an edentulous mandibular model and three dimensional photoelastic stress analysis was carried out to measure the fringe order around the implant supporting structure and also to calculate principal stress components at cervical area of each implant. The attachments tested were rigid and resilient type of Dolder bar, Round bar, Hader bar and Dal-Ro attchment. The results were as follows ; 1. In 2-implant supported overdenture using Round bar, Hader bar, and Dal-Ro attachment, compressive stress pattern was observed on the supporting structure of implant on loaded side, while tensile stress pattern in unloaded side. 2. In 2-implant supported overdenture using Dolder bar, the rigid Dolder bar shared the occlusal loads between 2 implants in a more favorable manner than was exhibited by the resilient type, while the resilient type placed a more stress on the distocervical area of the implant on the loaded side. But compressive stress pattern was observed in both the loaded and unloaded sides in either case. 3. In 2-implant supported overdenture, rigid and resilient type of Dolder bar exhibited more cross arch involvement than the Round bar, Hader bar, or Dal-Ro attachment. 4. In 4-implant supported overdenture using resilient Dolder bar and Hader bar, stress turned out to be distributed evenly among the implants between loaded and unloaded side, but thor was no reduction in the magnitude of the stress in the surrounding structure of implant contratry to 2-implant supported overdenture. 5. The stress pattern at cervical area of implant was different with the number of implant or the type of attachment but the overload, harmful to surrounding structure of implant, was not observed.

• The Journal of Korean Academy of Prosthodontics
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• v.61 no.1
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• pp.90-99
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• 2023

Implant overdentures are widely used as a treatment method to restore oral function in completely edentulous or partially edentulous patients with severe bone resorption. Using a milled bar, it is mechanically advantageous as the implant fixtures are splinted. Applying additional attachments to the bar has the advantage of dispersing the stress applied to the implant. In this case, a patient who used implant overdentures using 4 implants wanted to fabricate a new prosthesis due to repeated fractures of the denture and weakened retention. Milled bar with ADD-TOC attachment and zirconia prosthesis were fabricated by CAD-CAM method and mechanically and aesthetically satisfactory results were obtained.

• The Journal of Korean Academy of Prosthodontics
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• v.53 no.2
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• pp.150-156
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• 2015

As dental implant treatment becomes popular for both partial and complete edentulous patients, old people with complex systemic diseases also tend to prefer implant-assisted-overdenture or implant-supported-fixed prostheses to conventional complete denture. In this case, 77-year-old female who was on medication for hypertension and osteoporosis and paralyzed on right side due to stroke visited for implant-assisted-overdenture on lower jaw. After oral and radiographic examination, root-assisted magnet overdenture on upper jaw and implant-assisted magnet overdenture on lower jaw are planned. Consequently, overdentures using self-adjusting magnetic attachment(SA) system on both jaws resulted in recovering satisfying function and retention, which is enable to insert and remove with only one hand.

• Journal of the korean academy of Pediatric Dentistry
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• v.36 no.4
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• pp.613-618
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• 2009

Impacted molars are not usual with the prevalence rate of less than 1%, however problems such as infraocclusion, extrusion of the opposite tooth and lack of space are caused. If molars are impacted, radiographic check-up and observations are needed as they play an important role in skeletal development and mastication. Causes of impaction are underdevelopment of roots, supernumerary teeth, cysts, odontomas, ankylosis and etc. In our first case, we present impacted molar which was surgically exposed and orthodontically traded. As the developmental state of the root was less than half at first visit, we observed until the root was 2/3 in its length and traction was carried out. The second case is orthodontic traded molar with compleate enucleation of the existing cysts. When trading impacted molars, direct bonding of attachments to the tooth and light continuous forces are recommended so as to ankylosis, external absorption and periodontal attachment loss avoid. Fixed appliances tract the teeth on arch and obtain eruption spaces without patient's cooperation. We report surgically exposed and orthodontically traded molars which resulted in good occlusion and patients satisfaction.