• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.39
• /
• pp.2.1-2.6
• /
• 2017

Background: All clinicians are aware of the difficulty of installing a dental implant in posterior maxilla because of proximate position of maxillary sinus, insufficient bone width, and lower bone density. This study is to examine which factors will make the implantation in the posterior maxilla more difficult, and which factors will affect the postoperative implant stability in this region. Methods: Five hundred seventy-three fixtures on the maxilla posterior were included for this study from all the patients who underwent an installation of the dental implant fixture from January 2010 to December 2014 at the Department of Oral and Maxillofacial Surgery in Pusan National University Dental Hospital (Yangsan, Korea). The postoperative implant stability quotient (ISQ) value, fixture diameter and length, presence of either bone graft or sinus lift, and graft material were included in the reviewed factors. The width and height of the bone bed was assessed via preoperative cone beam CT image analysis. The postoperative ISQ value was taken just before loading by using the OsstellTM $mentor^{(R)}$ (Integration Diagnostics AB, Gothenburg, Sweden). The t test and ANOVA methods were used in the statistical analysis of the data. Results: Mean ISQ of all the included data was 79.22. Higher initial bone height, larger fixture diameter, and longer fixture length were factors that influence the implant stability on the posterior edentulous maxilla. On the other hand, the initial bone width, bone graft and sinus elevation procedure, graft material, and approach method for sinus elevation showed no significant impact associated with the implant stability on the posterior edentulous maxilla. Conclusions: It is recommended to install the fixtures accurately in a larger diameter and longer length by performing bone graft and sinus elevation.

• The Journal of Korean Academy of Prosthodontics
• /
• v.44 no.1
• /
• pp.85-102
• /
• 2006

Statement of problem: Currently, there are some 20 different geometric variations in implant/abutment interface available. The geometry is important because it is one of the primary determinants of joint strength, joint stability, locational and rotational stability. Purpose: As the effects of the various implant-abutment connections and the prosthesis height variation on stress distribution are not yet examined this study is to focus on the different types of implant-abutment connection and the prosthesis height using three dimensional finite element analysis. Material and method. The models were constructed with ITI, 3i TG, Bicon, Frialit-2 fixtures and solid abutment, TG post, Bicon post, EstheticBase abutment respectively. And the super structures were constructed as mandibular second premolar shapes with 8.5 mm, 11 mm, 13.5 mm of crown height. In each model, 244 N of vertical load and 244 N of $30^{\circ}$ oblique load were placed on the central pit of an occlusal surface. von Mises stresses were recorded and compared in the crowns, abutments, fixtures. Results: 1. Under the oblique loading, von Mises stresses were larger in the crown, abutment, fixture compared to the vertical loading condition. 2. The stresses were increased proportionally to the crown height under oblique loading but showed little differences with three different crown heights under vertical loading. 3. In the crown, the highest stress areas were loading points under vertical loading, and the finish lines under oblique loading. 4. Under the oblique loading, the higher stresses were located in the fixture/abutment interface of the Bicon and Frialit-2 systems compared to the ITI and TG systems. Conclusions: The stress distribution patterns of each implant-abutment system had difference among them and adequate crown height/implant ratio was important to reduce the stresses around the implants.

• Journal of the Korean Society for Precision Engineering
• /
• v.18 no.1
• /
• pp.98-103
• /
• 2001

Machining is the commonly used process in the manufacturing of prototypes. This process offers several advantages, such as rigidity of the machine, precision of the machine, precision of the operation and specially a quick delivery. The weight and immobility of the machine support and immobilize the part during the operation. However, despite these advantages it shows, machining still presents several limitations. The immobilization, location and support of the part are referred to as fixturing or workholding and present the biggest challenge for time efficient machining. So it is important to select and design the appropriate fixturing assembly. This assembly depends on the complexity of the part and the tool paths and may require the construction of dedicated fixtures. With traditional techniques, the range of fixturable shapes is limited and the identification of suitable fixtures in a given setup involves complex reasoning. To solve this limitation and to apply the automation, this paper presents the Reference Free Part Encapsulation(RFPE) and implementation of the encapsulation system. The feature-based modeling system and the encapsulation system are implemented. The small part of which it is difficult to find out the appropriate fixturing assembly is made by this system.

• Korean Institute of Interior Design Journal
• /
• no.16
• /
• pp.116-125
• /
• 1998

This study attempts to analyze the characteristics and changing trends of the interior design of modern Korean houses since 1960s and to understand the impacts of Western architecture and design. the photos of 101 houses were selected from the magazines published since 1960s. The data collected were analyzed via frequency percentage and average. The result reveals that the interior design of the living rooms in modern Korean houses has undergone lots of changes in finishing materials window treatments types of cabinets and use of lighting fixtures. It is concluded that 1960-1960s is a period of introducing Western design as a superior while 1980's is a period of exploring various ways toward harmony between Korean style and Western styles and 1990's is a period of settlement of koreanized modernism style.

• Journal of the Korean Society of Industry Convergence
• /
• v.7 no.4
• /
• pp.325-330
• /
• 2004

The forces acting on the tool are an important aspect of maching. For those concerned with the manufacture of machine tools, a knowledge of the forces in needed for estimation of power reguirements and for the design of machine tool elements tool-holders and fixtures, adequately rigid and free from vibration. The force reguired to form the chip is dependent on the shear yield strength of the work material un der cutting conditions which are cutting speed, workpiece, feedrate, insert type. In this study, FG, ML, MP, MC, C, RT inserts were investigated in turning using SM45C, SCM4, SKD11, SUS316, materials. The diameter of materials was 60mm, 80mm, 110mm. This paper presents MP were lowest and SKD11 were largest of the workpiece in cutting forces.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2001.10a
• /
• pp.255-259
• /
• 2001

The spring constant of a micro coil spring was measured by uniaxial tensile test. The inner diameter of it is $35{\mu}m$ and the pitch size is about $23{\mu}m$. A suing constant measurement system was developed. It consists of control units, load cell units, linear stages and several specially designed jigs and fixtures. Load and displacement are measured using a commercial load cell of 1000g capacity and a magnetic scale of $0.5{\mu}m$ resolution. In this study, a method to measure the spring constant of micro coil spring is presented and the relationship between misalignment of specimen and measurement error is discussed.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 2007.11a
• /
• pp.157-160
• /
• 2007

Recently, may high-rise buildings have been constructed, and will be constructed so that concerns about high-rise buildings have increased. We need to develop energy saving techniques immediately because the high-rise buildings consume a lot of energy. The most of effective energy saving method is the application of the efficient lighting designs and fixtures. The purpose of this study is to analyze the trend of lighting design, fixture and control system in Korea and it can be used the lighting application guide-line for the high-rise buildings.

• Journal of the Korean Academy of Esthetic Dentistry
• /
• v.8 no.1
• /
• pp.46-59
• /
• 1999

A fixed bridge is preferred as a prosthetic option supported by oral implants. However, it is very difficult to re tore edentulous maxilla with fixed prosthesis in cases with improper position and angulation of fixtures, abnormal jaw relation, and need for proper lip support. Six Br${\aa}$nemark implants were installed in edentulous maxilla opposing mandible with natural dentition. A removable hybrid prosthesis attached to a bar milled by 6 degrees was therefore designed to overcome such disadvantages of fixed prosthesis. Lateral stabilization of removable prosthesis was obtained by framework closely fitting the milled bar. Support for the prosthesis was ensured by three elevated areas on the bar. Two precision attachments(CEKA REVAX) provided appropriate direct and indirect retention without influencing support. A clinical and laboratory procedure was presented.

• The Journal of the Korean dental association
• /
• v.49 no.5
• /
• pp.279-285
• /
• 2011

Currently there is no dental ceramic material can be used in all dental situations need to be restored. However, in view of recent clinical reports, the most viable alternative is zirconia ceramic. Clinical success of dental zirconia restorations strongly depends on proper selection of materials, accurate laboratory procedure and final cementation, which can be achievable with the correct understanding of zirconia. As dental materials, zirconia ceramics have a very bright future, because they are being used increasingly in the anterior region as implant fixtures, as well as crown and bridge restorations and implant abutments. Many dental ceramics showing poor clinical performance have been gone from the dental market. However, in terms of outstanding mechanical properties and esthetic nature, new dental materials can replace zirconia ceramics will not be available in the foreseeable future.

• Proceeding of Spring/Autumn Annual Conference of KHA
• /
• 2000.11b
• /
• pp.123-129
• /
• 2000

The purpose of this study was to provide the fundamental data for the effective housing remodeling plan. Through the questionnaire survey, the actual conditions of remodeling in apartment housing were investigated. And as the result of statistic analysis, the relationships between characteristics of remodeling and building life-cycle, and family life-stage, were found out. The major findings of this study are as follows; 1) Most of apartment residents have remodeled the family living space and private living space. In detail, they performed remodeling frequently the change of finishing materials, facilities and equipments, and the change of the location of curtain wall ＆ storage fixtures. 2) It might be predicted that the building life-cycle was influential variable to predict apartment residents' remodeling. Therefore, in planning the support service for the remodeling, the building life-cycle should be taken into consideration.