PURPOSE: The aims of the study were to evaluate the fracture load of zirconia core material after dipping in coloring liquid at different time intervals and to compare the color of dipped blocks with that of prefabricated shaded blocks. MATERIALS AND METHODS: 3-unit bridge frameworks were designed digitally. Sixty frameworks were fabricated using uncolored zirconia blocks by CAD/CAM and divided into 4 groups randomly (n = 15). Group 2 (G2) was subjected to coloring liquids for 2 minutes, Group 4 (G4) for 4 minutes, and Group 6 (G6) for 6 minutes. CFS group was not subjected to any coloring procedure. After coloring, color differences between the test groups and a prefabricated shaded zirconia group (CPZ, n = 15) were evaluated by using a spectrophotometer. Fracture test was conducted immediately after shade evaluation with a Testometric test device at a cross-head speed of 1 mm/sec. Statistical analysis for evaluating color and fracture load was performed by using one way ANOVA followed by Tukey HSD test (P ≤ .05). Weibull analysis was conducted for distribution of fracture load. RESULTS: There was no difference in terms of fracture load and color between CFS (1176.681 N) and G2 (985.638 N) group and between CPZ (81.340) and G2 (81.140) group, respectively. Fracture load values of G4 (779.340 N) and G6 (935.491 N) groups were statistically significantly lower than that of CFS group (P ≤ .005). The color values of G4 (79.340) and G6 (79.673) groups were statistically different than that of CPZ group (P ≤ .005). CONCLUSION: Prolonged immersion of zirconia in coloring liquid not only negatively affected the fracture load of the zirconia being tested in the current study but also deteriorated the desired shade of the restoration.
Ceramics ; Immersion

The purpose of this study was to evalute the effect of immersion disinfection on the dimensional stability of rubber impression materials. The metallic master model was made in order to simulate the intraoral arch form. Impressions were made from four impression materials (Exaflex, Extrude, Reprosil, Impregum-F) and immersed in three disinfectant solutions (Wydex, Vi-Pon, Potadine). Casts from the impressions were measured according to the interpreparation distance. The A-B and The B-D abutment distance were compared with the control group and disinfected groups. The results were as follows; 1. The measurements of the stone cast increased relative to the master model and there was a significant difference (P<0.05). 2. The relative dimensional change of the stone cast as compared with master model ranged from 0.10% to 0.56% in the A-B distance and ranged from 0.04% to 0.27% in the B-D distance. 3. The dimensional change of the disinfected groups as compared with the control group was significantly different in the three impression materials except for Impregum-F (P<0.05). 4. The relative dimensional change of the disinfected groups compared with the control group ranged from 0% to 0.20% in the A-B distance and ranged from -0.09% to 0.11% in the B-D distance. These results suggest that immersion disinfection of rubber impression materials by chemical disinfectants causes very small dimensional change and the change is clinically acceptable for prothesis fabrication
Disinfectants ; Disinfection* ; Immersion* ; Rubber*

STATEMENT OF PROBLEM: Because dental impression can be a cross-infection source, disinfection, such as immersion disinfection is nessecary. However, the disinfection process may change the volume of the impression cast. PURPOSE: The purpose of this study is to find out the effects on dimensional change of different storage times and methods, of agar-alginate impression when immersed in a 5% idophor disinfectant. MATERIAL AND METHODS: An agar-alginate impression was made from a mandible model and then was disinfected and stored according the experimental conditions and a stone model was produced. Measurements were taken between reference points on the original mandible model and they were compared to measurements taken between reference points on the stone model. The study was divided into 4 groups. In group 1, the impression was stored in a 100% humidor for 30 minutes, 1 hour, 2 hours, 3 hours, 4 hours, 6 hours, 12 hours and 24 hours and stone models were made at each time. In group 2, the impression was immersed in 5% idophor disinfectant and then stored in a 100% humidor for the same length of times as group 1, and stone models were made at each time. In group 3, the impression was stored in extend-A-pourR, a special storage solution for 30 minutes, 1 hour, 2 hours, 3 hours, 4 hours, 6 hours, 12 hours, 24 hours 3 days, and 7 days and stone models were made at each time. In group 4, the impression was immersed in 5% idophor disinfectant and then stored in stored in extend-A-pourR, a special storage solution for the same length of times as group 3, and stone models were made at each time. 5 impressions and stone models were made at each time to make a total of 180. The Student-t test (P < .05) was used to do a statistical analysis of the measurements of the mandible model and stone models. The repeated-measure 2-way analysis of variance (P < .05) was used to do a statistical analysis of the difference in the 4 groups. RESULTS: The percent liner dimensional change was from 0.25+/-0.03% (group 1, 30 minutes) to 0.34+/-0.06% (group 4, 7 days). No significant change was noticed between the 4 groups. CONCLUSION: According to the above study, in both methods, least dimensional change was recorded when the storage times were short and in both methods, immersion in 5% idophor disinfectant did not effect dimensional change in the agar-alginate impression.
Disinfection* ; Immersion ; Mandible

OBJECTIVES: This study investigated the effect of red and white wine on color changes of nanofilled and nanohybrid resin composite. MATERIALS AND METHODS: Sixty specimens of each resin composite were prepared. Baseline data color values were recorded using a spectrophotometer. Three groups of discs (n = 20) were then alternately immersed in red, white wine, and deionized water (as a control) for twenty five minutes and artificial saliva for five minutes for four cycles. Specimens were then stored in artificial saliva for twenty two hours. This process was repeated for five days following immersion in artificial saliva for two days. Subsequently, the process was repeated again. Data were analyzed by two-way repeated ANOVA, one-way ANOVA, and Tukey's HSD. RESULTS: Red wine caused significantly higher color change (ΔE* > 3.3) than did white wine and deionized water (p < 0.05). Nanohybrid resin composites had significantly more color changes than nanofilled resin composite (p < 0.05). CONCLUSIONS: The effect of red and white wine on the color changes of resin composite restorative materials depended upon the physical and chemical composition of the restorative materials and the types of wine.
Immersion ; Saliva, Artificial ; Water ; Wine*

The purpose of this study was to evaluate the color changes of composite resin polymerized with three type of light curing units. Composite resin (Z100, shade A2) were applied in a cylindrical metal mold(2 mm thick, 7 mm diameter). Twenty specimens according to light curing units were made. Group1: the specimens were polymerized with Apollo 95E for 3seconds(1370 mW/cm2). Group2: the specimens were polymerized with XL 3000 for 40seconds(480 mW/cm2). Group3: the specimens were polymerized with Spectrum 800 for 10 seconds(250 mW/cm2) and 30 seconds(700 mW/cm2). The microhardness values(VHN) of upper and lower surfaces specimens after light polymerization were measured for the degree of polymerization. All specimens were stored in distilled water at 60degrees C for 30 days. The color characteristics(L*, a*, b*) of the specimens before and after immersion were measured by spectrophotometer and the total color difference (DeltaE*) was computed. The results obtained were as follows: 1. The microhardness values of Group I showed significantly lower than those of Group II and III(p<0.05). 2. In all groups the DeltaE* values presented below 2.0. 3. Group I showed the highest DeltaE* values followed order from highest to lowest by Group II and III (p<0.05).
Immersion ; Light ; Polymerization ; Polymers ; Water

The purpose of this study was to evaluate the color changes of composite resin polymerized with three type of light curing units. Composite resin (Z100, shade A2) were applied in a cylindrical metal mold(2 mm thick, 7 mm diameter). Twenty specimens according to light curing units were made. Group1: the specimens were polymerized with Apollo 95E for 3seconds(1370 mW/cm2). Group2: the specimens were polymerized with XL 3000 for 40seconds(480 mW/cm2). Group3: the specimens were polymerized with Spectrum 800 for 10 seconds(250 mW/cm2) and 30 seconds(700 mW/cm2). The microhardness values(VHN) of upper and lower surfaces specimens after light polymerization were measured for the degree of polymerization. All specimens were stored in distilled water at 60degrees C for 30 days. The color characteristics(L*, a*, b*) of the specimens before and after immersion were measured by spectrophotometer and the total color difference (DeltaE*) was computed. The results obtained were as follows: 1. The microhardness values of Group I showed significantly lower than those of Group II and III(p<0.05). 2. In all groups the DeltaE* values presented below 2.0. 3. Group I showed the highest DeltaE* values followed order from highest to lowest by Group II and III (p<0.05).
Immersion ; Light ; Polymerization ; Polymers ; Water

The purpose of this study was to evaluate the color changes of composite resin polymerized with three type of light curing units. Composite resin (Z100, shade A2) were applied in a cylindrical metal mold(2 mm thick, 7 mm diameter). Twenty specimens according to light curing units were made. Group1: the specimens were polymerized with Apollo 95E for 3seconds(1370 mW/cm2). Group2: the specimens were polymerized with XL 3000 for 40seconds(480 mW/cm2). Group3: the specimens were polymerized with Spectrum 800 for 10 seconds(250 mW/cm2) and 30 seconds(700 mW/cm2). The microhardness values(VHN) of upper and lower surfaces specimens after light polymerization were measured for the degree of polymerization. All specimens were stored in distilled water at 60degrees C for 30 days. The color characteristics(L*, a*, b*) of the specimens before and after immersion were measured by spectrophotometer and the total color difference (DeltaE*) was computed. The results obtained were as follows: 1. The microhardness values of Group I showed significantly lower than those of Group II and III(p<0.05). 2. In all groups the DeltaE* values presented below 2.0. 3. Group I showed the highest DeltaE* values followed order from highest to lowest by Group II and III (p<0.05).
Immersion ; Light ; Polymerization ; Polymers ; Water

The purpose of this study was to investigate the cytotoxicity and mutagenicity of denture ase resins. According to manufacturer's instructions, resin specimens were made. Group 1: heat-polymerizing acrylic resin (Luciton 199(R)). Group 2: heat-polymerizing acrylic resin containing polyhedraloligosilsesquioxane(POSS esin). Group 3: auto-polymerizing acrylic resin (Repair Acrylic(R)). Group 4: direct relining auto-polymerizing acrylic resin (Tokuso Rebase(R)). Fresh specimens, 24 hrs. and 72 hrs. soaked specimens in distilled water were made. Responses with metabolic assay and mutagenesis assay to eluates from resin specimens were measured. Cultures with medium alone provided controls. Cytotoxicity was assessed with agar overlay test. The results were as follows: 1. Group 4 showed higher cytotoxicity than Group 1, Group 2 and Group 3 in fresh, 24-and 72-hour immersion cases (p<.05). Group 3 showed higher cytotoxicity than Group 2 in fresh cases and showed higher cytotoxicity than Group 1 and Group 2 in 24-and 72-hour immersion cases (p<.05). Group 1 and Group 2 showed no significant difference. 2. All acrylic denture base resins showed significant increase of cell activity as immersion time increased (p<.05). 3. Auto-polymerizing acrylic denture base resins showed higher cytotoxicity than heat-polymerizing acrylic denture base resins (p<.05). 4. All acrylic denture base resins showed lower mutagenicity than controls (p<.05).
Agar ; Denture Bases* ; Dentures* ; Immersion ; Mutagenesis ; Water

PURPOSE: The purposes of this study were to evaluate the staining resistance of CAD/CAM resin-ceramics polished with different techniques and to determine the effectiveness of the polishing techniques on resin-ceramics, comparing it with that of a glazed glass-ceramic. MATERIALS AND METHODS: Four different CAD/CAM ceramics (feldspathic ceramic: C-CEREC Blocs, (SIRONA) and three resin-ceramics: L-Lava Ultimate, (3M ESPE), E-Enamic, (VITA) and CS-CeraSmart, (GC)) and one light cure composite resin: ME-Clearfil Majesty Esthetic (Kuraray) were used. Only C samples were glazed (gl). Other restorations were divided into four groups according to the polishing technique: nonpolished control group (c), a group polished with light cure liquid polish (Biscover LV BISCO) (bb), a group polished with ceramic polishing kit (Diapol, EVE) (cd), and a group polished with composite polishing kit (Clearfil Twist Dia, Kuraray) (kc). Glazed C samples and the polished samples were further divided into four subgroups and immersed into different solutions: distilled water, tea, coffee, and fermented black carrot juice. Eight samples (8 × 8 × 1 mm) were prepared for each subgroup. According to CIELab system, four color measurements were made: before immersion, immersion after 1 day, after 1 week, and after 1 month. Data were analyzed with repeated measures of ANOVA (α=.05). RESULTS: The highest staining resistance was found in gl samples. There was no difference among gl, kc and cd (P>.05). Staining resistance of gl was significantly higher than that of bb (P<.05). Staining resistances of E and CS were significantly higher than those of L and ME (P<.05). CONCLUSION: Ceramic and composite polishing kits can be used for resin ceramics as a counterpart of glazing procedure used for full ceramic materials. Liquid polish has limited indications for resin ceramics.
Ceramics ; Coffee ; Daucus carota ; Immersion ; Tea ; Water

PURPOSE: Beverages may affect the translucency of esthetic dental restorative materials. The aim of the present study was to investigate the effects of coffee and red wine on the translucency of a PICN material with two translucency levels, and finished with different methods. MATERIALS AND METHODS: 2M2 high translucent and translucent VITA Enamic hybrid ceramic blocks were investigated. Rectangular specimens with the dimensions of 12 mm × 14 mm × 2 mm were prepared. The specimens were finished and polished with different methods as suggested by the manufacturer. The translucency parameters of the specimens were evaluated before and after 24 hours, 7 days, and 28 days immersion in distilled water, coffee and red wine. Translucency parameters were measured using a portable spectrophotometer. RESULTS: At the end of 28 days, there was no statistically significant difference between the groups of specimens kept in coffee (P>.05). In the red wine groups, there was a statistically significant difference between the control group and all other groups (P<.05) at the end of 28 days. CONCLUSION: The translucency of hybrid ceramic for a restoration may not be important regarding the effects of coffee on translucency change because the specimens with different translucencies and finishing methods that were immersed to coffee had similar translucency parameters at the end of 28 days. The translucency of hybrid ceramic may be important in the case of red wine, however, since the results showed that highly translucent specimens exposed to red wine demonstrated better translucency parameters than specimens made from translucent blocks at the end of 28 days.
Beverages ; Ceramics ; Coffee ; Immersion ; Methods ; Water ; Wine