Study On Constructing Microstructures Inspired By Octopus Suction Cups On The Surface Of Silicone Rubber Soft Denture Liner In Vitro

Objectives: The microstructures inspired by octopus suction cups is constructed on the surface of silicone rubber soft lining materials to evaluate its impact on adhesion in vitro,and provide theoretical and technical support for further producing the tissue surface of complete denture base with it,and explore new ideas to improve retention of complete denture.Methods: The experimental groups used nano Arch S130 3D printing system to print the negative resin mold of microstructures inspired by octopus suction,and then used Silagum-Comfort silicone rubber material to turn over mold.The silicone rubber samples were divided into 5 groups according to the parameters of microstructures.The parameters of each group were 100 μm,200 μm,300 μm,400 μm and 500 μm,named as group A,B,C,D and E.The control group was set as plane silicone rubber samples without microstructure.Accuracy of production technology was evaluated by scanning electron microscopy to characterize microstructures and adsorption force of samples in each group were tested by universal mechanic material tester under simulated oral environment in vitro.Then statistical analysis was conducted.Results: The deviation between 3D-printing negative mold and predetermined size was about 7～9%,while that between microstructures made from silicone rubber material and predetermined size reduced to 1～5%.Samples of experimental group A,B and C had bubbles and the bubble rate was about 50%.After optimizing the production process on the oscillator,the bubble rate dropped below 5%,and the size had not changed significantly.Experimental group D and E had no large number of bubbles.Adhesion of experimental groups were（0.20±0.04）N,（0.16±0.03）N,（0.13±0.04）N,（0.12±0.02）N,（0.14±0.02）N,（0.12±0.03）N while control group was（0.12±0.03）N.Adhesion of experimental group A and B increased significantly,which were statistically different compared to control group（P<0.05）.Conclusions: On the surface of silicone rubber soft denture liner,constructing octopus suction cup-liked microstructures with diameter of 100 μm and 200 μm can improve adsorption.Making octopus suction cup-liked microstuctures on tissue surface of complete denture base may improve the retention of it.