A toothbrush assembly including a toothbrush and a toothpaste cartridge. The toothbrush includes: a handle having a compartment to receive the toothpaste cartridge a head having bristles a door covering an opening of the compartment and a conduit running from the compartment to the head to deliver toothpaste from the toothpaste cartridge in the compartment to the head and the bristles. The toothpaste cartridge includes: a housing having a cavity to store toothpaste a piston having threads a paste plate coupled to the piston via the threads a knob coupled to the piston to turn the piston to move the paste plate along the piston toward the head of the toothbrush to dispense the toothpaste from the cavity to through the conduit into the bristles and an end plate having at least one hole to discharge the toothpaste from the cavity of the cartridge to the conduit of the toothbrush
