This study was performed to investigate the effects of tooth mobility and design of the direct retainer on the stress of supporting tissues in distal extension removable partial denture. Tooth mobility was simulated and four different types of direct retainer such as Akers clasp, I-bar clasp, wrought wire, and Dalbo attachment were designed and stress o the supporting tissues were measured and analyzed with straingauge method. The following conclusions were drawn from this study. 1. The stress revealed at the lingual side of alveolar bone of the abutment tooth in edentulous area was the largest. 2. The stress at the lingual side of alveolar bone of the abutment tooth in edentulous area was increased according to the increases of tooth mobility in I-bar clasp and Dalbo attachment. 3. The stress at the residual ridge crest was the great in Dalbo attachment on mobility 0, in I-bar clasp on mobility 1, and in wrought wire clasp on mobility 2. 4. There was little changes of stress according to the increase of tooth mobility at buccal and lingual side of the residual ridge crest and around the abutment teeth in dentulous area.
Denture, Partial, Removable* ; Tooth Mobility* ; Tooth*

The purpose of this study was to investigate the possibility on recycling of IPS Empress ceramic for the wide use of esthetically pleased IPS-Empress ceramic in clinical prosthodontic treatment. The specimens were made of first, second, and third pressed IPS Empress ceramic and were immersed in 0.05% methylene blue solution for 24hours. The amount of color change before and after stainning was measured with colorimeter(Model Tc-6Fx, Denshoku Co., Tokyo, Japan). The change of E in first pressed ceramic was 18.33 and those in second and third pressed ceramics were 19.33 and 19.93 respectively. Although there was statistical difference among them, the differences were minute and acceptable. From the results of this study, the possibility of recycling of IPS Empress ceramic could be suggested.
Ceramics* ; Methylene Blue ; Prosthodontics ; Recycling

Simulation of naturally appearing enamel in fixed prosthodontics could be achieved with all ceramics. The purpose of this study was to investigate the stain resistance of 4 different all ceramics materials (In-ceram, IPS Empress, Celay, Vintage). Forty specimens were prepared using manifacture's instruction and the samples were divided into two groups. The specimens for one group were glazing and those for other group wee ground to remove the glazing layer. All specimens were immersed in methylene-blue for 24hours. The color values for each specimen was measured with colorimeter (Mode Tc-6Fx, Tokyo Denshoku Co.) prior to and after immersion in methylene-blue. The following conclusions were drawn from this study. 1. The stain resistance of glazing ceramics was higher than that of unglazing ceramics. 2. The changes of E* and L* values were revealed in Vintage and unglazing Celay. 3. The changes of a* values were revealed in unglazing vintage, Celay, In-cream. 4. The changes of b* value were revealed in Vintage, IPS Empress and unglazing Celay.
Ceramics* ; Crowns* ; Dental Enamel ; Immersion ; Prosthodontics

No abstract available.
Arm*

This study was performed to investigate the distribution and magnitude of stress at supporting tissue of abutment teeth and residual ridge tissue with remaining unilateral posterior teeth. Four types of removable partial dentures that included clasp retained removable partial denture, attachment retained removable partial denture, telescopic removable partial denture, and swing-lock partial denture were designed, and strain gauge was used for stress analysis. Each prosthesis was subjected to simulated vertical and oblique load. The following conclusions were drawn from this study. 1. The clasp retained removable partial denture generally distributed simulated vertical force more evenly to the supporting structure. 2. The stress at buccal side of 1st premolar was the lowest in swing-lock partial denture and that was highest in attchment retained removable partial denture. The stress at lingual side of 1st premolar was the lowest in telescopic partial denture. 3. In clasp retained removable partial denture, stress was lower at load site and ridge crest at midline, but it was higher at lst premolar area on vertical load. 4. In attachment removable partial denture, stresses at buccal side of 1st premolar, lingual side of 1st premolar on vertical load, and ridge crest at midline on oblique load were higher. 5. In telescopic removable partial denture, stress at lingual side of 1st premolar was the least in all removable partial dentures, but the stress at load site was higher. 6. In swing-lock removable partial denture, stress at buccal side of 1st premolar was the lowest, and stresses at load site and distal end of residual ridge crest were higher.
Bicuspid ; Denture Design* ; Denture, Partial ; Denture, Partial, Removable ; Dentures* ; Prostheses and Implants ; Tooth*

No abstract available.
Humans ; Muscle Spasticity*

No abstract available.
Adolescent* ; Humans

No abstract available.
Crowns*

No abstract available.
Alloys* ; Dental Porcelain*

No abstract available.
Denture, Partial, Fixed*