Applicator for one-handed operation for storing and applying a dental liquid comprising a cavity, a container containing the dental liquid and a conduit (28, 29) by means of which the dental liquid is guidable from the container to a surface of an applicator tip of the applicator, - the container being slideable relative to the conduit, - a channel being arranged in the conduit (28, 29), connecting the inside of the container to the applicator tip and, optionally, to a distributor arranged thereto, - the applicator having a handhold at the end of the applicator opposing the applicator tip, by means of which the container is pushable into the cavity, the cavity taking up the side walls of the container when the container is being slid over the conduit (28, 29), - a seal being arranged at the ingress of the conduit (28, 29) into the container preventing the dental liquid from ingressing into the cavity, - the container being made from a foil or at least regions thereof comprising a foil closing the container in a fluid-tight manner, the container being closed by a foil at the end of the container facing the conduit (28, 29), - a mandrel being arranged in the applicator by means of which the foil is puncturable, the container with punctured foil being opened, and the mandrel being arranged in the region of the conduit (28, 29) and of the container, particularly preferably being formed as hollow mandrel forming a first end of the conduit (28, 29), - the applicator comprising a displacing piston for extruding the dental liquid from the container, and the displacing piston being arranged at one end of the container inside the container and being slideable relative to the container, and the displacing piston remaining in the same place relative to the conduit (28, 29) when the side walls of the container are being slid into the cavity so that the dental liquid is being pushed out of the inside of the container through the conduit (28, 29), and the container being positioned with respect to the mandrel such that the driving mechanism which is used for extruding the dental liquid from the applicator is also used to puncture or slit the foil with the mandrel, the container being opened by the same force by means of which the dental liquid is dispensed, and one-handed operability of the applicator being attained not only when the dental liquid is being dispensed but also when the container is being opened. - the container being slideable relative to the conduit, - a channel being arranged in the conduit (28, 29), connecting the inside of the container to the applicator tip and, optionally, to a distributor arranged thereto, - the applicator having a handhold at the end of the applicator opposing the applicator tip, by means of which the container is pushable into the cavity, the cavity taking up the side walls of the container when the container is being slid over the conduit (28, 29), - a seal being arranged at the ingress of the conduit (28, 29) into the container preventing the dental liquid from ingressing into the cavity, - the container being made from a foil or at least regions thereof comprising a foil closing the container in a fluid-tight manner, the container being closed by a foil at the end of the container facing the conduit (28, 29), - a mandrel being arranged in the applicator by means of which the foil is puncturable, the container with punctured foil being opened, and the mandrel being arranged in the region of the conduit (28, 29) and of the container, particularly preferably being formed as hollow mandrel forming a first end of the conduit (28, 29), - the applicator comprising a displacing piston for extruding the dental liquid from the container, and the displacing piston being arranged at one end of the container inside the container and being slideable relative to the container, and the displacing piston remaining in the same place relative to the conduit (28, 29) when the side walls of the container are being slid into the cavity so that the dental liquid is being pushed out of the inside of the container through the conduit (28, 29), and the container being positioned with respect to the mandrel such that the driving mechanism which is used for extruding the dental liquid from the applicator is also used to puncture or slit the foil with the mandrel, the container being opened by the same force by means of which the dental liquid is dispensed, and one-handed operability of the applicator being attained not only when the dental liquid is being dispensed but also when the container is being opened.