| Objective: In this experiment,tensile strength test,effects of thermal cycling on silicone rubber with silver-loaded nano.Ag-TiO2 soft lining material and the bonding strength between the resin base,the failure mode of the specimen was observed by means of a microscope,study on the water absorption and solubility of hot and cold recycled materials,it provides a theoretical reference for the clinical application of silicone rubber soft lining material.Methods: 1.specimen preparation: conventional box,box for cooking to prepare specifications for 20 mm×10 mm×6mm into the denture base resin blocks 60,the resin blocks were divided into 3 groups,namely A,B,C,group.A-control group: the cuboid model with the specification of 43mm×10mm×6mm was prepared with the conventional wax film,silagum silicone rubber impression material according to the size of the model made by die.The two resin blocks are bonded to the silicone rubber mold cavity,there are 10 mm×6 mm×3 mm space between the bonding surfaces of the two resin blocks in the silicone rubber offset die.The silicon rubber soft lining and the prepared silver nano.Ag-TiO2 dioxide antibacterial agent with a mass ratio of 3% are uniformly mixed,between 2 resin blocks,glass plate to squeeze out bubbles.After the material polymerization,the specimens were polished,the A-control group was made of 10 pieces.B-complex aging group: With the A-control group the same preparation method of silver nano-soft lining denture base resin complex 10 blocks,in the cold and hot cycle instrument for the 40000 cold and hot cycle.C-base resin aging group: 10 base resin aging of thermoplastic resin block in thermal cycling machine in after 40000 thermal cycles,each pair then respectively and the silver nanometer soft lining material is bonded,made of 10 pieces of specimen base aging group.2.the three groups of specimens in the universal material testing machine for tensile strength testing,the failure mode of the specimen was observed by means of a microscope,scanning electron microscopy was used to observe the dispersion of antibacterial agents in the material.3.the A group of materials for 20000 cycles,weighing and measuring with B group,The water absorption and dissolution rate were calculated.Results: 1.The tensile strength(MPa)of A group and B group were 4.155±0.441 and 3.662±0.6174(P > 0.05),the main failure mode of the specimen is the failure of polymer,the results show that the bonding strength between materials is greater than that of the tear strength.The tensile strength value(MPa)of the C group was 2.884 ±0.931(compared with A and B two groups,P < 0.05),adhesive failure is the main failure mode of C group,the results show that compared with A and B group,the bond strength is weakened.2.the water absorption and dissolution rate of A group is(1.642±0.253)?(0.395±0.120)?,Group B is(2.216±0.389)?(0.683±0.199)?.Compared with A group,B group had significant difference in water absorption and dissolution rate(P <0.05).Conclusion: 1.after the lining of the silicone rubber lining containing the silver nano titanium dioxide antibacterial agent and the new resin base,after aging treatment,it has no influence on the long-term effect of the bonding strength between the base resin and the silver lining.2.the soft lining material of silver and the aging(old)base resin after the re lining,the bond strength between the obviously reduced,but still meet the clinical needs(>0.44MPa).3.with the increase of the number of hot and cold cycles,the water absorption rate and the dissolution rate of the material have increased,but the change range is small,so that in the course of the use of the material to maintain long-term stability and biological security. |
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