ABSTRACT
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.
ABSTRACT
PURPOSE: The aim of this in vitro study was to evaluate the effect of aging on the tear strength and cytotoxicity of four soft denture lining materials. MATERIALS AND METHODS: Four commonly used soft denture lining materials, (Coe-Comfort(TM) GC America Inc., Alsip, IL, USA; Coe-Soft(TM) GC America Inc., Alsip, IL, USA; Visco-gel Dentsply Caulk Milford, DE, USA; and Sofreliner Tough M Tokuyama Dental Corporation Tokyo, Japan) were selected. Sixty trouser-leg designed specimens per lining material were fabricated using a stainless steel mold for tear strength testing. The specimens were divided into non-thermocycling and 1000-, and 3000- thermocycling groups. For the cytotoxicity test, twenty-four disk shaped specimens per material were fabricated using a stainless steel mold. The specimens were soaked in normal saline solution for 24 h, 48 h and 72 h. Cytotoxicity was measured by XTT assay in L929 mouse fibroblasts. Data were analyzed by two way analysis of variance and Dunnett's test (P<.05). RESULTS: Before thermocycling, Sofreliner Tough M (10.36 +/- 1.00 N) had the highest tear strength value while Coe-Comfort(TM) (0.46 +/- 0.10 N) had the lowest. After 3000 cycles, Sofreliner Tough M (9.65 +/- 1.66 N) presented the highest value and Coe-Comfort(TM) (0.42 +/- 0.08 N) the lowest. Sofreliner Tough M, in all incubation periods was the least toxic with significant differences compared to all other materials (P<.05). Coe-Comfort(TM), Coe-Soft(TM), and Sofreliner Tough M did not show any significant differences within their material group for all incubation periods. CONCLUSION: This in vitro study revealed that aging can affect both the tear strength and cytotoxicity of soft denture materials depending on the composition.
Subject(s)
Animals , Mice , Aging , Americas , Dentures , Fibroblasts , Fungi , Sodium Chloride , Stainless SteelABSTRACT
Objective To evaluate the mechanical properties of SEI silicone for maxillofacial prosthesis before and after heat aging and explore its clinical value. Methods Two kinds of silicones, SEI and A-2186, were performed heat aging for 24, 48 and 72 h. The parameters of tear strength, tensile strength, elongation at break and hardness of them were detected under ordinary state and at different time points after heat aging. Statistic comparison and analysis were conducted. Results Tear strength, tensile strength and elongation at break of A-2186 silicone were more favorable than those of SEI silicone under ordinary state, while the parameter of hardness was an exception (P < 0.05). After heat aging and with time progress, tear strength, tensile strength and elongation at break significantly decreased and hardness significantly increased for both A-2186 silicone and SEI silicone (P < 0.05). After heat aging, tear strength and tensile strength of A-2186 silicone were more favorable than those of SEI silicone, while the latter had a minor change in hardness. Conclusion Compared with the worldwide commonly used A-2186 silicone, there is room for improvement in tear strength and tensile strength for SEI silicone. Given the favorable property of minor change in hardness after heat aging, SEI can be used as a prosthetic material for facial soft tissue defect.