No abstract available.

No abstract available.
Denture, Partial, Removable*

No abstract available.
Denture, Partial, Removable*

No abstract available.
Humans

No abstract available.
Humans ; Temporomandibular Joint Disorders* ; Temporomandibular Joint*

No abstract available.
Denture, Partial, Removable*

STATEMENT OF PROBLOM: In the internal connection system the loading transfer mechanism within the inner surface of the implant and also the stress distribution occuring to the mandible can be changed according to the abutment form. Therefore it is thought to be imperative to study the difference of the stress distribution occuring at the mandible according to the abutment form. PURPOSE: The purpose of this study was to assess the loading distributing characteristics of 3 implant systems with internal connection under vertical and inclined loading using finite element analysis. MATERIAL AND METHOD: Three finite element models were designed according to the type of internal connection of ITI(model 1), Friadent(model 2), and Bicon(model 3) respectively. This study simulated loads of 200N in a vertical direction (A), a 15 degree inward inclined direction (B), and a 30 degree outward inclined direction (C). RESULT: The following results have been made based on this numeric simulations. 1. The greatest stress showed in the loading condition C of the inclined load with outside point from the centric cusp tip. 2. Without regard to the loading condition, the magnitudes of the stresses taken at the supporting bone, the implant fixture, and the abutment were greater in the order of model 2, model 1, and model 3. 3. Without regard to the loading condition, greater stress was concentrated at the cortical bone contacting the upper part of the implant fixture, and lower stress was taken at the cancellous bone. 4. The stress of the implant fixture was usually widely distributed along the inner surface of the implant fixture contacting the abutment post. 5. The stress distribution pattern of the abutment showed that the great stress was usually concentrated at the neck of the abutment and the abutment post, and the stress was also distributed toward the lower part of the abutment post in case of the loading condition B, C of the inclined load. 6. In case of the loading condition B, C of the inclined load, the maximum von Misess stress at the whole was taken at the implant fixture both in the model 1 and model 2, and at the abutment in the model 3. 7. The stress was inclined to be distributed from abutment post to fixture in case of the internal connection system. CONCLUSION: The internal connection system of the implant and the abutment connection methods, the stress-induced pattern at the supporting bone, the implant fixture, and the abutment according to the abutment connection form had differenence among them, and the stress distribution pattern usually had a widely distributed tendency along the inner surface of the implant fixture contacting the a butment post.
Finite Element Analysis ; Mandible ; Neck ; Prostheses and Implants*

Clinically, the curve of Spee is widely applied as a determined level of the occlusal curvature when the oral rehabilitation and the reconstruction of the prosthesis is needed at the malalignment dentition due to the missing, extrusion, and the inclination of the teeth. The purpose of this study was to analyze the curve of Spee of the occlusal curvature which influences to the occlusal form and the location three dimensionally, and then was to measure the radius and the degree of curvature of the curve of Spee and also was to investigate the influence to the cuspal inclination according to the change of the inclination of the curve of Spee which was analyzed by AutoCAD R.13 program at the gnathological cast and the cephalometric radiograph. The following results were obtained : 1. The radius of the curve of Spee was the mean of 11.74+/-3.64cm in the model, 12.75+/-4.63cm in the radiograph and there was no significant difference statistically between the model and the radiograph(P >0.001). 2. The radius and the degree of curvature of the curve of Spee showed negative correlation(r=-0.80), while the radius and the degree of curvature of the curve of Spee in relation to the length of the curve of Spee did not show correlation. 3. The case of the curve of Spee inclined to the posterior, that is, Post.Mtheta group showed the mean of 4.73+/-3.64 , positive cerrelation to the P2m, M1mm, M1dm, M2dm, and especially the greatest correlation coefficient to the mesial inclination angle of the mesio-buccal cusp tip of the first molar(r=0.70). 4. The case of the curve of Spee inclined to the anterior, that is, Ant.Mtheta group showed the mean of 3.28+/-3.59, positive cerrelation to the P2m, M1mm, and also the greatest correlation coefficient to the mesial inclination angle of the mesio-buccal cusp tip of the first molar(r=0.78)
Dentition ; Prostheses and Implants ; Radius ; Rehabilitation ; Tooth

STATEMENT OF PROBLEM: There are common clinical cases in which the mandibular first and second molars are missing unilaterally. PURPOSE: This study was designed to compare and evaluate the magnitude and distribution of stress produced by four kinds of mandibular unilateral free-end removable partial dentures that could be applied clinically in Kennedy class II cases. MATERIAL AND METHODS: Four unilateral free-end removable partial dentures using clasp, Konus crown, resilient attachment, and flexible resin were fabricated on the photoelastic models of the Kennedy class II cases. The vertical load of 6kg was applied on the central fossa of the first molar of every removable partial denture in the stress freezing furnace and the photoelastic models were frozen according to the stress freezing cycle. After these models were sliced mesio-distally to a thickness of 6mm, the photoelastic isochromatic white and black lines of the sliced specimens were examined with the transparent photoelastic experiment device and photographs were taken with a digital camera. The fringe order numbers at eight measuring points in the photograph were measured with the naked eye. RESULTS: The maximum fringe order number of each sliced specimen and the fringe order number at the residual ridge just below the loading point were in the decreasing order of the unilateral removable partial dentures using flexible resin followed by clasp, resilient attachment, and Konus crown. The fringe order number at the root apex of the second premolar was in the decreasing order of the unilateral removable partial dentures using clasp followed by flexible resin, Konus crown, and resilient attachment. CONCLUSION: The removable partial denture using Konus crown showed the most equalized stress distribution to the supporting alveolar bone of abutment teeth and residual ridge under the vertical loads. The removable partial denture using flexible resin can be applied to the case that has a better state of residual ridge than abutment teeth.
Bicuspid ; Crowns ; Denture, Partial, Removable ; Eye ; Freezing ; Humans ; Molar ; Tooth

A lot of the research paper was reported about the result of influence of IMC (Intramobile connector)in the IMZ implant placed solely in the alveolar bone, but reports about the effect of IMC on functional load at state of connecting with natural teeth were rare. The major purpose of this study was find the mechanical character of IMC itself by using the finite element analysis program after simulated variance of condition connected with the natural teeth and implant on functional load. When first and second premolar was lost, IMZ implant was placed with a diameter of 3.3 mm and a length of 13mm with IMC in second premolar area. Rigid connection was done and the non-figid connection was located on the female part of the canine abutment and the implant respectively and then both the infraocclusion of 30um and the non-infraocclusion under the load of 40kg applied to the portion of the natural teeth, the pontic and the implant. The displacement and the stress of it was estimated and analyzed IMC itself of the rigid connection and the non-rigid connection was grouped. The following results were obtainded. 1. In all groups, the displacement of Y-axis was greater than that of X-axis and the aspect of displacement showed that IMC was displaced downward and to the center. 2. There was no differences in the displacement of IMC regardless of the connection type. 3. In the displacement of IMC, I 4 was the least, I 1 and I 3 are similar and I 2 was the greatest. 4. There was no differences in the peak value of miximal stress of IMC regardless of the connection type. 5. In the peak value of maximal stress of IMC, I 4 was the least, I 1 and I 3 ere similar, and I 2 was the largest.
Bicuspid ; Denture, Partial, Fixed* ; Female ; Finite Element Analysis* ; Humans ; Tooth*