• The Journal of the Korean dental association
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• v.15 no.4
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• pp.261-263
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• 1977

• The Journal of the Korean dental association
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• v.33 no.12 s.319
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• pp.886-887
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• 1995

• 대한치과보철학회:학술대회논문집
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• 1999.04a
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• pp.36-40
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• 1999

• The Journal of Korean Academy of Prosthodontics
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• v.36 no.6
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• pp.878-887
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• 1998

Although attachments have been utilized for a retainer of removable prostheses during several decades, there is little information on the force distribution by the attachments. This study was undertaken to evaluate the stress patterns developed by partial dentures employing rigid attachments on the supporting structures. Four types of the mandibular removable partial dentures were designed depending upon the position of the rigid attachment and the existency of lingual bracing. Under 100N of vertical and 25N of lateral loads on the 1st and 2nd lower molar of partial denture, stress distribution patterns and displacement were analysed with three dimensional finite element method by ANSYS version 5.3. 1. The highest stresses were concentrated on the distal alveolar crest of posterior abutment and the second stresses on the apical region of posterior abutment in the models. 2. The greatest displacement were shown on the distal alveolar crest of posterior abutment and the second displacement on the distal alveolar crest of anterior abutment in the models. 3. There was little difference between the models with intraoral attachment and those with extracoronal attachment. 4. There was little difference between the models with and without the lingual bracing.

• The Journal of Korean Academy of Prosthodontics
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• v.28 no.1
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• pp.43-61
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• 1990

The laser reflexion method is a new technique which permits precise contactless measurement and observation of tooth mobility as well as tooth movement. The purposes of this study were to clarify the reliability of the laser reflexion method in clinical application and to measure the abutment tooth movement according to clasp design. This study was designed to determine 1) How much a bending movement of the impression plate stand affects the position of the reflexion pattern and how precise the patient bites into plate 2) Which clasp design causes greater movement of the abutment tooth. Under medium and maximum bite forces, tests were performed on central loading position which was 13mm distal to terminal abutment tooth of distal extension removable partial denture. The movement in the mesiodistal and buccolingual directions was measured. The Duncan's New Multiple-Range test was used to compare the means for the four castings under each direction-load combination; and the paired sample t-test was for medium and maximum bite forces. From this experiment, the following results were obtained. 1. The Roach clasp, the combination clasp, the RPI clasp, and the Akers clasp did not significantly differ in their effects on buccolingual movement of the abutment tooth. 2. The direction of abutment tooth movement was not significantly altered by clasp design and all abutment tooth movements were oriented distobuccally. 3. Under medium bite force, the Akers clasp caused greater distal movement of the abutment tooth than did the combination clasp and the RPI clasp. Under maximum bite force, the Akers clasp caused greater distal movement of the abutment tooth than did the RPI clasp. 4. The testing apparatus and procedures used in this study(laser reflexion method) proved to be reliable in clinical application.

• The Journal of the Korean dental association
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• v.10 no.8
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• pp.535-537
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• 1972

The author observed good clinical results applying the I Bar attachment in the case of distal extension partial denture construction.

• The Journal of the Korean dental association
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• v.23 no.1 s.188
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• pp.45-60
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• 1985

• The Journal of Korean Academy of Prosthodontics
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• v.56 no.3
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• pp.218-226
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• 2018

In partial edentulous patients, implant-assisted removable partial denture which provide additional retention and support by placing a small number of implants in strategic positions might be suitable treatment. This case of patient with loss of maxillary posterior teeth and moderate to severe wear of residual dentition, three implants were placed in the maxillary anterior edentulous area and then surveyed bridges were made including remaining anterior natural teeth. Posterior edentulous area was restored with distal extension removable partial denture (RPD). In addition, the worn mandibular natural teeth were restored with fixed prostheses. As a result, reduced vertical dimension and collapsed occlusal plane were rehabilitated, and improved functionally and aesthetically. The purpose of this case was to report the results of three-year follow-up of full mouth rehabilitation with anterior implant surveyed bridges and distal extension RPD.

• Journal of Technologic Dentistry
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• v.8 no.1
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• pp.85-90
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• 1986

The effect of splinting on aqbutment tooth distal movement was performed in vitro study. An acrylic resin mandibular model with missing 2nd premolars, molars and a removable partial denture framework were constructed. The roots of the canines, 1st premolars and edentulous ridges were coated with silicone rubber. A modified Ney Surveyor was used for vertical load appkication, and abutment tooth distal movement were measured with a dial gauge with four conditions of splinting methods were tested by applying unilateral vertical loadings. The results are follows; 1. The magnitude of abutment tooth distal movement on the non-load side was less 40$\sim$69% than that occurred on the load side. 2. On the load side, reducing effect of splinting on abutment tooth movement in the condition of load side double abutment(30%), non-load side double abutment(10%), double abutments of both sides(40%) was compared with single abutments of both sides. 3. On the non-load side, reducing effect of splinting on abutment tooth movement in the condition of load side double abutment(5%), non-load side double abutment(22%), double abutments of both sides(59%) was compared with single abutments of both sides. 4. The magnitude of abutment tooth distal movement in the condition of double abutments of both sides was less 40$\sim$59% than that in the condition of single abutments of both sides.

• The Journal of Korean Academy of Prosthodontics
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• v.33 no.4
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• pp.780-806
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• 1995

The purpose of this study was to describe the application of 3D finite element analysis to determine resultant stresses on the bone anchored fixed prosthesis, implants and supporting bone of the mandible according to fixture numbers and load conditions. 4 or 6 fixtures and the bone anchored fixed prosthesis were placed in 3D finite element mandibular arch model which represents an actual mandibular skull. A $45^{\circ}$ diagonal load of 10㎏ was labiolingually applied in the center of the prosthesis(P1). A $45^{\circ}$ diagonal load of 20㎏ was buccolingually applied at the location of the 10mm or 20mm cantilever posterior to the most distal implant(P2 or P3). The vertical distribution loads were applied to the superior surfaces of both the right and the left 20mm cantilevers(P4). In order that the boundary conditions of the structure were located to the mandibular ramus and angle, the distal bone plane was to totally fixed to prevent rigid body motion of the entire model. 3D finite element analysis was perfomed for stress distribution and deflection on implants and supporting bone using commercial software(ABAQUS program. for Sun-SPARC Workstation. The results were as follows : 1. In all conditions of load, the hightest tensile stresses were observed at the metal lates of prostheses. 2. The higher tensile stresses were observed at the diagonal loads rather than the vertical loads 3. 6-implants cases were more stable than 4-implants cases for decreasing bending and torque under diagonal load on the anterior of prosthesis. 4. From a biomechanical perspective, high stress developed at the metal plate of cantilever-to-the most distal implant junctions as a consequence of loads applied to the cantilever extension. 5. Under diagonal load on cantilever extension, the 6-implants cases had a tendency to reduce displacement and to increase the reaction force of supporting point due to increasing the bendign stiffness of the prosthesis than 4-implants cases. 6. Under diagonal load on cantilever extension, the case of 10mm long cantilever was more stable than that of 20mm long cnatilever in respect of stress distribution and displacement. 7. When the ends of 10mm or 20mm long cantilever were loaded, the higher tensile stress was observed at the second most distal implant rather than the first most distal implant. 8. The 6-implants cases were more favorable about prevention of screw loosening under repeated loadings because 6-implants cases had smaller deformation and 4-implants cases had larger deformation.