| Objective:The purpose of this study was to synthetize polymeric hydrogel denture adhesive,and to evaluate their the tensile bond strength test and the effect of hemolysis.So this experiment can provide theoretical basis for clinical applications in the future.Methods:1.By using mixed solvents, hydrophobic poly vinyl acetate and hydrophilic poly methyl vinyl ether-alt-maleic anhydride with two different molecular weight were cross-linked to synthetize polymeric hydrogel, respectively for No.1 and No.2 material.2.Commercially available denture adhesive as a control group,No.1 and No.2materials were used as the experimental groups.Tensile test was done with the universal material testing machine.The test machine was used to test the tensile bond strength of the three kinds of materials,and these samples were tested immediately and immersed in artificial saliva for 1 hour.3.The above two kinds of material were prepared their saline extract according to State Standard of the People’s Republic of China GB/T 16886.12-2005.Hemolysis test was carried out according to YY/T 0127.1-93“biological test method of oral materialsâ€,and the absorbance value was measured by ultraviolet spectrophotometer,then was used to calculated the rate of haemolysis.Samples of each material were dissolved to artificial saliva.The pH values were measured immediately after preparation and at 1-, 2-, 3-,4-, 6-,12-, and 24-h intervals using a digital pH meter.Also the two kinds of material saline extraction by the NaHCO3 buffer were to reach the pH-value of normal blood which is keptbetween 7.35 and 7.45,the same way tested the rate of hemolysis.Results:1.The tensile bond strength values of No.1 and No.2 material confected immediatly were better than those of commercially available denture adhesive,P<0.05,the difference was statistically significant.The bond strength value of No.2 material was greater than No.1,which had statistical meaning(P<0.05).After immersed in artificial saliva No.1 and No.2 material was gradually dissolved,and unable to measure the bond strength value.2.The hemolysis rate of the No.1 material is 67.76%,and No.2 material is 46.60%without adjusting the pH value.They were more than 5% and did not meet the requirements of the standard.It pointed that the material exhibited hemolysis effect.The tested material generally were acidic and remained relatively pH-stable in 24 h,which ranged from 4.45 to4.80 and 4.51 ~ 4.85,respectively.With NaHCO3 buffer the two kinds of material saline extracts,the hemolysis rate was 2.38%,1.20% respectively.These value were less than5%.They met to the medical requirements.Conclusions:1.The two kinds of synthetic polymer hydrogel denture adhesive material have good instant tensile bond strength,but the delay of adhesive tensile strength is insufficient.2.The two kinds of synthetic polymer hydrogel denture adhesive materials have hemolytic effect, the reason may be related to the pH value of the material acidity. |
