No abstract available.

No abstract available.
Dentures*

No abstract available.
Denture Bases* ; Dentures*

No abstract available.
Rubber* ; Wettability*

The purpose of this study was to evaluate the effect of proportional thickness of various reline materials on the transverse strength of denture base. The denture base resin used in this study was Vertex RS (Dentimex Zeist., Holland). The reline resins used were Tokuso rebase normal set (Tokuyama Corp., Japan), Rebaron (GC Corp., Japan), KoolinerTM(GC INC., U.S.A). New trulinerTM(Harry J. Bosworth Co., U.S.A). The bulk specimens with 2.5mm thickness of denture base were prepared as the control group. Group 1 was fabricated with 2.0mm thickness of denture base and 0.5mm reline material, group 2 with 1.5:1.0mm. group 3 with 1.0:1.5mm, group 4 with 0.5:2.0mm composition. Measurements of transverse strength were taken for each specimens. The results were as follows: 1. Regardless of the reline resin type, the transverse strength of denture base was decreased after reline procedure. 2. The transverse strength according to the reline resin type was decreased in the following order : Rebaron, Tokuso rebase, Kooliner, and then New truliner and there was a significant difference among the reline materials (P<0.05). 3. The strength of the relined denture base generally decreased as the proportional thickness of the denture reline material increased. These results suggest that increasing the proportional thickness of the reline material progressively decreased the strength of the relined denture base. Thus, the denture base should not be unnecessarily altered during the reline procedure.
Denture Bases* ; Dentures*

This study was performed to evaluate effect on color and opacity of 3 different copy-milled In-Ceram cores by glass infiltration and porcelain veneering. Color was evaluated by the CIEL*a*b* readings were recorded with a Colorimeter, Color difference value( E*ab) was calculated and opacity was represented by the contrast ratio. The variance of each color parameter (L*, a*, b*), color difference value, and opacity change after glass-infiltrated and veneered with porcelain was compared. Three experimental groups were fabricated as follows. Group 1 (Alumina core) : 15 Alumina blanks was infiltrated with originally marketed glass (A1) and veneered with porcelain(A1) Group 2 (modified Alumina core) : 15 Alumina blanks was infiltrated with its associated glass(S11) and veneered with porcelain(A1) Groups 3 (Spinell core) : 15 Spinell blanks was infiltrated with originally developed glass(S11) and veneered with porcelain(A1) The results were as follows: 1. After glass infiltration, L* value showed decrease, a* value showed decrease only group 1(p<0.001) and b* value showed increase on group 1, increase on group 1, increase on group 2, 3(p<0.001). 2. After porcelain veneering L* value showed decrease(p<0.001), a* value showed increase on group 1, decrease on group 2(p<0.05) and b* value showed decrease on group 1, increase on group 2, 3(p<0.001). 3. E* ab between before and after galss infiltration was more than 13.77, and between after glass infiltration and after porcelain veneering more than 19.63. 4. After glass infiltration and porcelain veneering, Alumina showed the lowest L*, a* value and highest b* value among 3 different groups (p<0.05). E*ab between group 1-2, 1-3 was higher than that of group 2-3. 5. After glass infiltation, opacity showed decrease, Group 1 had the highest opacity(p<0.05), but no significant differences between group 2 and 3. Above results suggest that glass infiltration and porcelain veneering effects on color and opacity of In-Cream core, and that modified In-Ceram Alumina uses single crowns of bridges like In-Cream Spinell.
Aluminum Oxide* ; Crowns ; Dental Porcelain ; Glass ; Reading

No abstract available.

No abstract available.
Crowns*

No abstract available.
Denture, Overlay*

The purpose of this study was to evaluate the effects of thermocycling on the shear bond strength of Co-Cr alloy to denture base resin. PMMA denture base resin such as heat-cured Vertex-RS , self-cured Vertex-SC and 4-META denture base resin such as heat-cured Meta-Dent , self-cured Meta-Fast was bonded to Co-Cr alloy. Samples were divided into 3 groups : no thermocycling group as control, thermocycling between 5degrees C and 55degrees C with 15 second dwell time as group 1, thermocycling with 1 minute dwell time as group2. The shear bond strength was measured and the interface between metal and resin was observed by SEM. The results were as follows. 1. The shear bond strength decreased significantly according to thermocycling and dwell time(P<0.001). 2. The bond strength of Co-Cr alloy and 4-META denture base resin was significantly higher than that of Co-Cr alloy and PMMA denture base resin(P<0.001). 3. IN SEM, there was no gap in control group, but there was much and large gap in group 1, 2. The longer dwell times, the lower bond strength. PMMA denture base resin had more gap than 4-META denture dwell times, the lower bond strength. PMMA denture base resin had more gap than 4-META denture base resin in the interface. These results revealed that thermocycling decreased the bond strength between Co-Cr alloy and denture base resin and dwell time of thermocycling changed the effect of thermocycling. The results suggested that oral temperature change affect the bond strength of prosthesis.
Alloys* ; Denture Bases* ; Dentures* ; Polymethyl Methacrylate ; Prostheses and Implants