No abstract available.
Rubber* ; Wettability*

The purpose of this study was to investigate the contact angles and wettability of conventional dental stones and improved dental stones and newly developed dental stones on several impression materials. Materials included in this study were several dental stones and newly developed dental stone; 2 type III stones (Snow Rock, New Diastone), 6 type IV stones(Crystal Rock, Vel Mix, Fuji Rock, Tuff Rock, Resin Rock and newly developed dental stone) and 1 type V stone (Die Keen). Contact angles on the impression materials were measured with contact angle measuring device. Ten specimens for each material, total 180 specimens were made on void entrapment model. The two impression materials (Handae, GC) were used to produce 9 groups of die stone casts form void entrapment model. Voids in the stone casts were counted under a stereoscopic microscope. The grad for the reproduction ability of each materials on the void entrapment model was calculated from the casts by one examiner. From the experiment, the following results were obtained : 1. The newly developed stones showed smallest contact angle. Type III dental stone had larger contact angles than type IV and V stones. Contact angle was much affected by the impression materials. 2. Resin containing die materials such as Tuff Rock and Resin Rock had smallest void number than any other groups. 3. In comparing reproduction parameters, Tuff Rock and Resin Rock presented superior results, while Vel Mix showed lowest reproduction ability.
Reproduction ; Wettability*

STATEMENT OF PROBLEM: Die materials require abrasion resistance, dimensional stability with time, and high surface wettability for adequate material properties. Wear of gypsum materials is a significant problem in the fabrication of accurately fitting cast prosthetic devices. So It has been recommended that the use of die hardener before carving or burnishing ofthe wax pattern. PURPOSE: The purpose of this study was to compare the abrasion resistance and surface microhardness(Knoop) with 3 commonly used gypsum die materials(MG Crystal Rock, Super plumstone, GC FUJIROCK(R) EP) with and without the application of 2 die hardeners. MATERIAL AND METHODS: Three die materials were evaluated for abrasion resistance and surface microhardness after application of 2 die hardeners(Die hardener and Stone die & plaster hardener). Thirty specimens of each gypsum material were fabricated using an impression of resin die(Pattern resin; GC Corporation, Japan) with 1-mm high ridges, sloped 90 degrees. Gypsum materials were mixed according to manufacturer's recommendations and allowed to set 24 hours before coating. Specimens were arbitrary assigned to 1 of 3 treatment subgroups (n=10/subgroup): no treatment(control), coated with Die hardener, and coated with Stone die & plaster hardener. Abrasion resistance(measured by weight loss) was evaluated using device in 50g mass perpendicular to the ridges. Knoop hardness was determined by loading each specimen face 5 times for 15 seconds with a force of 50g. A scanning electron microscope was used to evaluate the surface of specimens in each treatment subgroup. Conclusions: The obtained results were as follows: 1. 3 types of die stone evaluated in this study did not show significant differences in surface hardness and abrasive resistance(P<.05). 2. In the abrasive resistance test, there were no significant differences between GC FUJIROCK(R) EP and MG Crystal Rock with or without 2 die hardener(P<.05). 3. Super plumstone treated with Stone die & plaster hardener showed increased wear loss(P<.05). 4. Die hardener coatings used in this study decreased the surface hardness of the gypsum material(P<.05).
Calcium Sulfate* ; Hardness ; Wettability

STATEMENT OF PROBLEM: When an implant is fixed, a fixture comes into contact with a tissue fluid. Adhesion of a tissue fluid to a surface of implant is various case by case. PURPOSE: The ultimate goal of this work is to analyze a correlation between a surface roughness and wettability of implant specimens. A measurement for wettability is performed considering 4 types of specimen implant with surface treatments different from each other to investigate the change of wettability with the elapse of time. MATERIAL AND METHODS: Firstly, 20 specimens of titanium were prepared. The specimen were made of a commercial Titanium Grade IV with the diameter of 10 mm and the thickness of 1 mm. According to the method of surface treatment, the specimens were classified into 4 groups of 5 specimens per group. Group A: Machined Surface Group B: Anodized surface Group C: RBM (HA blasting) surface Group D: CMP (calcium methaphosphate) coating surface. Surface roughness of specimen was measured using SV-3000S4 (Mituyoto, Japan). The measurement was based on the standard of JIS1994. Sessile drop method was used to measure the wettability, which measures contact angle between implant disc and saline with the time interval of 5, 10, and 15 seconds. SPSS 11.0 was used to analyze the collected data. In order to analyze the difference of wettability and surface roughness according to implant surface treatment method. The statistical significance was tested with the confidence level of 95 percent. Pearson's correlation coefficient was used to evaluate the correlation of surface roughness and wettability. RESULTS: The difference of surface roughness was statistically significant in the order of Group C (1.69 +/- 0.26), Group D (1.58 +/- 0.16), Group B (0.78 +/- 0.14) Group A (0.18 +/- 0.05). The wettability has also a statistically significant difference, which was in the order of group B (17.70 +/- 2.66), Group C (27.86 +/- 4.52), Group D (66.28 +/- 3.70) Group A (70.52 +/- 8.00). There was no difference in wettability with the passage of time. CONCLUSIONS: 1. The surface roughness was high in the order of RBM, CMP, Anodized, Machined group (P < .05). 2. The wettability was high in the order of Anodized, RBM, CMP, Machined group (P < .05). 3. There was no statistical significance in the correlation of surface roughness and wettability.
Surface Properties ; Titanium ; Wettability

Wettability of addition silicone impression material is very important property for making an accurate restoration. This study examined the impression quality in clinical condition and the wet tability of impression and die material. Four commercially available addition silicone impression material (Express, Examix, Contrast, Perfect) and three die materials (Die-Keen, Vel-Mix, FujiRock) were studied. A total of 50 putty/wash and heavy body/wash impressions of wet intact permanent molar teeth were examined for definition of the gingival sulcus reproduction and then classified in quality ranking. The percentage of the sulcus reproduction ability of each material was calculated from the sulcus depths of cross-sectioned epoxy resin casts from the impressions and clinically measured sulcus depths. The same impression materials were used to produce 3 groups of die stone casts form void entrapment die had been exposed to milk. Voids in the impression. body and stone casts were counted under a stereoscopic microscope. From the experiment, the following results were obtained 1. Sulcus reproduction ability of additional silicone impression material were diminished in order of Express, Examix, Perfect, Contrast. The significant difference was found between Perfect and other material. Heavy body/wash combination was superior to putty/wash method in Perfect impression material. 2. In direct observation, bontrast showed least void in impression body but correlations were not found between sulcus reproduction and void production. 3. In void entrapment laboratory test, wettability were diminished in order of Examix, Contrast, Express, Perfect. Clinical impression recording seems not to correlate with laboratory test. 4. The wettability of die material to impression material was not different in Express, Examix, Contrast. But, in Perfect, Die-Keen had superior wettability to others.
Milk ; Molar ; Reproduction ; Silicones ; Tooth ; Wettability*

The indirect technique for making cast restoration requires that dies be as accurate and durable as possible. Currently, stone is the most commonly used material for die. However, it has some problems such as the weakness in its strength and low abrasion resistance. Recently, epoxy resin die systems have become available. The purpose of this study was to examine two commercially available resin die systems and evaluate some characteristics for their clinical performance. This study evaluated the dimensional accuracy of epoxy resins and their wettability with impression materials. In this study, the first experiment was about dimensional accuracy of different die materials. The master model was made of stainless steel. 10 models were made of two epoxy resins (Die-epoxy, Tri-epoxy) and a die stone (Fujirock) each. Occlusal diameter (Dimension I), occluso-gingival height (Dimension II), and interabutment distance (Dimension III) wee measured in each model. Next, the contact angles of die materials with impression materials were observed. The blocks were made of polyether, hydrophilic additional silicone, polysulfide impression materials. By dropping the same amount (0.05ml) of Tri-epoxy, Die-epoxy, and die stone on the blocks, 10 samples of each die material were made. After setting of materials, the contact angles were measured. The results of this study were as follows. 1. The expansion of stone die and the shrinkage of resin dies in occlusal diameter were observed, and stone and Tri-epoxy were expanded and Die-epoxy was shrinked in occluso-gin-gival height. There was little change among materials in interabutment distance (p>0.05). 2. In comparison with the mater model, Tri-epoxy had the least variation in measurement of the three die systems examined. Did-epoxy was next, and die stone showed the greatest variation. 3. The compatibility of die stone for polyether, hydrophilic additional silicone, polysulfide decreased in order, wherease epoxy materials had the decreased compatibility for polyether and polysulfide, hydrophilic additional silicone in order. It was not statistically different between polyether and polysulifide (p>0.05). 4. The contact angles of Tri-epoxy, Die-epoxy, die stone were getting bigger in order.
Epoxy Resins* ; Silicones ; Stainless Steel ; Wettability

The purpose of this study was to investigate the effects of the anodization and cyclic calcification treatment on the surface characteristic and bioactivity of the titanium thin sheet in order to obtain basic data for the production of bioactive titanium membrane. A 30×20×0.08 mm titanium sheets were prepared, and then they were pickled for 10 seconds in the solution which was mixed with HNO₃: HF: H₂O in a ratio of 12: 7: 81. The TiO₂ nanotube layer was formed to increase the specific surface area of the titanium, and then the cyclic calcification treatment was performed to induce precipitation of hydroxiapatite by improvement of the bioactivity. The corrosion resistance test, wettability test and immersion test in simulated body solution were conducted to investigate the effect of these surface treatments. The nanotubes formed by the anodization treatment have a dense structure in which small diameter tubes are formed between relatively large diameter tubes, and their inside was hollow and the outer walls were coupled to each other. The hydroxyapatite precipitates were well combined on the nanotubes by the penetration into the nanotube layer by successive cyclic calcification treatment, and the precipitation of hydroxyapatite tended to increase proportionally after immersion in simulated body solution as the number of cycles increased. In conclusion, it was confirmed that induction of precipitation of hydroxyapatite by cyclic calcification treatment after forming the nanotube TiO₂ nanotube layer on the surface of the titanium membrane can contribute to improvement of bioactivity.
Corrosion ; Durapatite ; Immersion ; Membranes ; Nanotubes ; Titanium ; Wettability

Based on the defects in powder properties of the contents of Ziyin Yiwei Capsules, this study screened out the main medicinal slice powders causing the poor powdery properties, and introduced the powder modification process to improve the powdery properties of these slice powders, the pharmaceutical properties of the capsule contents, and the content uniformity of Ziyin Yiwei Capsules, so as to provide a demonstration for the application of powder modification technology to the preparation of Chinese medicinal solid preparations. Through the investigation on the powder properties of the contents of Ziyin Yiwei Capsules, it was clarified that the pulverized particle size of the capsule contents had a good correlation with the pulverization time. According to the measurement results of the powder fluidity and wettability, the quality defects of the capsule contents were caused by the fine powders of Taraxaci Herba and Lungwortlike Herba. "Core-shell" composite particles were prepared from medicinal excipients magnesium stearate and fine powders of Taraxaci Herba and Lungwortlike Herba slices after ultra-fine pulverization to improve the powder properties of the problematic fine powders. Powder characterization data including fluidity and wettability were measured, followed by scanning electron microscopy(SEM) and infrared ray(IR) detection. It was determined that the optimal dosage of magnesium stearate was 2%, and the compositing time was 3 min. The composite particles were then used as content components of the Ziyin Yiwei Capsules. The powder characteristics between the original capsule and the modified composite capsule including the particle size, fluidity, wettability, uniformity of bulk density, and uniformity of chromatism as well as the content uniformity and in vitro dissolution were compared. The results showed that the powder characteristics and content uniformity of the prepared composite capsule were significantly improved, while the material basis of the preparation was not changed before and after modification. The preparation process was proved to be stable and feasible. The powder modification technology solved the pharmaceutical defects that were easy to appear in the preparation of traditional capsules, which has provided experimental evidence for the use of powder modification technology for improving the quality of Chinese medicinal solid preparations and promoting the secondary development and upgrading of traditional Chinese medicinal dosage forms such as capsules.
Capsules ; Excipients ; Particle Size ; Powders ; Wettability

The wear debris of ultra-high molecular weight polyethylene (UHMWPE) used as a bearing material in total joint arthroplasty evokes a serious adverse biological reaction (osteolysis). In this study, therefore, the wear resistance of UHMWPE is enhanced by attaching a hydrophilic graft on the UHMWPE surface and by improving surface hardness without deteriorating the mechanical properties, which may result in the formation of lubrication film and the increased resistance to penetration, scratching or deformation during articulation. This was done by ion-implantation technique. The results showed that the wettability and the surface hardness of the modified UHMWPE by the above treatments increased due to the increased cross-linking density and hydrophilic graft attachment on the surface. The wear test was performed by a wear testing machine of pin-on-disk type. The modified UHMWPE revealed about 30~50% less volumetric wear than the control specimen. It was also shown that the volumetric wear depended not only on the optimal treatment condition but on the applied load and the sliding speed.
Arthroplasty ; Hardness ; Joints ; Lubrication ; Molecular Weight* ; Osteolysis ; Polyethylene* ; Transplants ; Wettability

PURPOSE: The object of this study was to investigate the effect of UV irradiation (by a general commercial UV sterilizer) on anodized titanium surface. Surface characteristics and cellular responses were compared between anodized titanium discs and UV irradiated anodized titanium discs. MATERIALS AND METHODS: Titanium discs were anodized and divided into the following groups: Group 1, anodized (control), and Group 2, anodized and UV irradiated for 24 hours. The surface characteristics including contact angle, roughness, phase of oxide layer, and chemical elemental composition were inspected. The osteoblast-like human osteogenic sarcoma (HOS) cells were cultured on control and test group discs. Initial cellular attachment, MTS-based cell proliferation assay, and ALP synthesis level were compared between the two groups for the evaluation of cellular response. RESULTS: After UV irradiation, the contact angle decreased significantly (P<.001). The surface roughness and phase of oxide layer did not show definite changes, but carbon showed a considerable decrease after UV irradiation. Initial cell attachment was increased in test group (P=.004). Cells cultured on test group samples proliferated more actively (P=.009 at day 2, 5, and 7) and the ALP synthesis also increased in cells cultured on the test group (P=.016 at day 3, P=.009 at day 7 and 14). CONCLUSION: UV irradiation induced enhanced wettability, and increased initial cellular responses of HOS cells on anodized titanium surface.
Carbon ; Cell Proliferation ; Humans ; Osteosarcoma ; Titanium ; Ultraviolet Rays ; Wettability