A dental syringe may include a replaceable valve cartridge containing one or more valves. The valves may include air and water valves using a seating surface and an opposing seating surface with a relative angle formed between the two surfaces. The relative angle allows for regulation of the flow of fluid traveling through the valves. The replaceable valve cartridge may also include a system to remove a residual liquid from a tip of a dental syringe. Additionally, the replaceable valve cartridge may include a seal that prevents bleed-over of fluids within a dental syringe through use of first and second rings of elastic portions of the seal with a low pressure zone defined in between. Further, the dental syringe may include a tip retention insert which may be replaceable and may use either a pair of plates or a plurality of ball bearings to retain the dental syringe tips.
