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Objective To compare bacterial blocking rate of different medical packaging material,as well as weight loss rate,tear strength,and abrasion resistance of cotton cloth with different times of washing.Methods According to test methods for sterile medical device packaging,bacterial blocking rates of cotton cloth,non-woven fabric,and disposable filter paper were tested.Weight loss test,tensile test,and abrasion resistance test of cotton cloth were performed to test weight loss rate,tear strength,and abrasion resistance of cotton cloth with different times of washing.Results In test for microbial barrier ranking of porous package material,the average bacterial blocking rates of double-layer new cotton cloth,double-layer old cotton cloth,disposable filter paper,and nonwoven fabric were 62.15％,31.39％,82.04％,and 89.71％ respectively;after cotton cloth was washed 30 times,the weight loss rate decreased by 1.22％,tear strength decreased by 6.70％,fabric-rubbing test revealed there was no pilling.Conclusion Bacterial blocking effect ranked as follows:non-woven fabric,disposable filter paper,doublelayer cotton cloth.After 30 times of washing,the weight loss rate and tear strength decreased,and bacterial blocking effect was worse than that of new cotton cloth.
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@#ObjectiveTo study the method of testing abrasion resistance of axillary crutch tips. MethodsA test method based on pressure analysis in normal use of axillary crutches was suggested, which characterized: put 450 N on axis of the tip; the tip or text surface sway 60° for 500000 times in frequency of 40 /min; maximal abrasion thickness after test should be less than 3.3 mm. Experimental facilities were established to carry out fatigue test of wearability. ResultsThe test method suggested can reflect tips abrasion in real context. ConclusionThe text method can be used for tips abrasion and fatigue resistance adjustment.
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The purpose of this study was to evaluate the abrasion resistance of surface penetrating sealant which was applied on a composite resin restoration and to provide proper time to reapply sealant on composite resin surface. Two hundred rectangular specimens, sized 8 x 3 x 2 mm, were made of Micronew (Bisco, Inc., Schaumburg, IL, U.S.A) and divided into two groups; F group (n = 10) was finished with coarse and medium grit of Sof-Lex discs and BisCoverwas applied B group (n = 190) after finishing with discs. B group was again subdivided into nineteen subgroups. From B-1 group to B-18 group were subjected to toothbrush abrasion test using a distilled water-dentifrice slurry and toothbrush heads. B-IM group was not subjected to toothbrush abrasion test. Average surface roughness (Ra) of each group was calculated using a surface roughness tester (Surfcorder MSE-1700: Kosaka Laboratory Ltd., Tokyo, Japan). A representative specimen of each group was examined by FE-SEM (S-4700: Hitachi High Technologies Co., Tokyo, Japan). The data were analysed using cluster analysis, paired t-test, and repeated measure ANOVA. The results of this study were as follows; 1. Ra of F group was 0.898 +/- 0.145 microm and B-IM group was 0.289 +/- 0.142 microm. Ra became higher from B-1 group (0.299 +/- 0.48 microm) to B-18 group (0.642 +/- 0.313 microm). 2. Final cluster center of Ra was 0.361 microm in cluster 1 (B-IM ~ B-7), 0.511 microm in cluster 2 (B-8 ~ B-14) and 0.624 microm in cluster 3 (B-15 ~ B-18). There were significant difference among Ra of three clusters. 3. Ra of B-IM group was decreased 210.72% than Ra of F group. Ra of B-8 group and B-15 group was increased 35.49% and 51.35% respectively than Ra of B-IM group. 4. On FE-SEM, B-IM group showed the smoothest resin surface. B-8 group and B-15 group showed vertically shallow scratches, and wide and irregular vertical scratches on composite resin surface respectively. Within a limitation of this study, finished resin surface will be again smooth and glazy if BisCover would be reapplied within 8 to 14 months after applying to resin surface.
Subject(s)
HeadABSTRACT
The purpose of this study was to evaluate the abrasion resistance of surface penetrating sealant which was applied on a composite resin restoration and to provide proper time to reapply sealant on composite resin surface. Two hundred rectangular specimens, sized 8 x 3 x 2 mm, were made of Micronew (Bisco, Inc., Schaumburg, IL, U.S.A) and divided into two groups; F group (n = 10) was finished with coarse and medium grit of Sof-Lex discs and BisCoverwas applied B group (n = 190) after finishing with discs. B group was again subdivided into nineteen subgroups. From B-1 group to B-18 group were subjected to toothbrush abrasion test using a distilled water-dentifrice slurry and toothbrush heads. B-IM group was not subjected to toothbrush abrasion test. Average surface roughness (Ra) of each group was calculated using a surface roughness tester (Surfcorder MSE-1700: Kosaka Laboratory Ltd., Tokyo, Japan). A representative specimen of each group was examined by FE-SEM (S-4700: Hitachi High Technologies Co., Tokyo, Japan). The data were analysed using cluster analysis, paired t-test, and repeated measure ANOVA. The results of this study were as follows; 1. Ra of F group was 0.898 +/- 0.145 microm and B-IM group was 0.289 +/- 0.142 microm. Ra became higher from B-1 group (0.299 +/- 0.48 microm) to B-18 group (0.642 +/- 0.313 microm). 2. Final cluster center of Ra was 0.361 microm in cluster 1 (B-IM ~ B-7), 0.511 microm in cluster 2 (B-8 ~ B-14) and 0.624 microm in cluster 3 (B-15 ~ B-18). There were significant difference among Ra of three clusters. 3. Ra of B-IM group was decreased 210.72% than Ra of F group. Ra of B-8 group and B-15 group was increased 35.49% and 51.35% respectively than Ra of B-IM group. 4. On FE-SEM, B-IM group showed the smoothest resin surface. B-8 group and B-15 group showed vertically shallow scratches, and wide and irregular vertical scratches on composite resin surface respectively. Within a limitation of this study, finished resin surface will be again smooth and glazy if BisCover would be reapplied within 8 to 14 months after applying to resin surface.
Subject(s)
HeadABSTRACT
Foi propósito deste estudo avaliar a resistência à abrasão de dentes artificiais de resina de 7 diferentes marcas comerciais, previamente submetidos a hidratação em saliva artificial. Foram utilizados primeiros molares inferiores das marcas Artplus, Biolux, Myerson, SR Orthosit, Trilux, Trubyte Biotone e Vipi Dent Plus, divididos em 7 grupos (n = 12), totalizando 84 corpos-de-prova. Após serem confeccionados em embutidora metalográfica sob pressão de 150 kgf.cm-2, durante 16 minutos, os corpos-de-prova permaneceram imersos em saliva artificial à temperatura constante de 37 ± 1°C durante 30 dias. Em seguida foram submetidos ao ensaio de desgaste em politriz metalográfica, sob pressão de 200 gramas e velocidade constante, durante 10 minutos. A resistência foi avaliada pelo método gravimétrico em balança de precisão, segundo as diferenças porcentuais das massas de cada corpo-de-prova antes e após o ensaio. Os valores obtidos foram submetidos à análise de variância e posteriormente ao teste comparativo de Tukey (p < 0,05). Observou-se diferença estatisticamente significante entre o grupo SR Orthosit e os demais grupos, que não apresentaram diferença significante entre si. Ante as condições testadas, as marcas Artplus, Biolux, Myerson, Trilux, Trubyte Biotone e Vipi Dent Plus apresentaram comportamento semelhante, demonstrando menor resistência à abrasão quando comparadas ao grupo SR Orthosit, que apresentou maior resistência
Subject(s)
Tooth, Artificial , Dental Restoration Wear , Prostheses and Implants , Saliva, Artificial , In Vitro Techniques , Data Interpretation, StatisticalABSTRACT
The purpose of this study was to investigate the abrasion resistance and surface roughness of conventional dental stones and improved dental stones and newly developed dental stones. Materials included in this study were several dental stones and newly developed dental stone; 2 type III, 6 type IV(including newly developed dental stone),1 type V Ten specimens for each material,total ninety specimens were made. Each specimen was subjected to 50 complete cycle abrasion under constant load 0.42N at speed of 6mm per sec.The depth after abrasion test was measured for each specimen. Surface roughness before and after abrasion test was compared.The results were as follows ; 1.The resin containing die materials such as Tuff Rock and Resin Rock had superior abrasion resistance. 2.Type IV,V Surface roughnessdental stone exhibited greater abrasion resistance than Type IIIdental stone. 3.The results of the surface roughness showed similar pattern with the abrasion resistance.