Silicone rubber belongs to high molecular synthetic rubber. As an impression material, it has the advantages of high strength, good elasticity and fluidity, good plasticity, stable size, high precision and stable chemical properties. It is the most ideal type of impression material at present. . Mainly used for some precision restorations. Clinical attention should be paid to the blending of silicone rubber impression materials and the preparation of models:

(1) When using metal trays, especially non-porous trays, in order to prevent the impression from being released from the tray, a tray adhesive can be used.

(2) When nurses knead the silicone rubber impression material by hand, they should use disposable polyethylene plastic film gloves, or remove the gloves and wash their hands, and operate in a dry environment, and the setting time is about 2 minutes. The use of latex gloves and humid environments will prolong the cohesion time of the silicone rubber, while latex gloves containing talc will affect the complete polymerization of the silicone rubber.

(3) When manually preparing silicone rubber, it should be prepared with fingertips, mixed evenly, and the palm of the hand is prohibited. The high temperature of the palm can accelerate the solidification of the silicone rubber, and the blending ratio given by the manufacturer according to different materials must be used, so as not to cause a decrease in strength and affect the taking. Die accuracy.

(4) When stirring the silicone rubber, the unmixed silicone rubber in the slow period should be removed to avoid affecting the curing of the model.

(5) Due to the high strength of silicone rubber, it is more difficult to demold the model than the alginate impression material, so the demolding operation should be very careful to prevent the abutment from breaking.

(6) When the silicone rubber impression is taken, the tray should be kept fixed before the impression is completely cured, so as to prevent the elasticity of the silicone rubber impression from lifting the tray and deforming the impression.

(7) The silicone rubber must be fully polymerized for half an hour after taking the mold to prevent the mold taking error.