The American Dental Association (ADA) has established criteria for acceptance of local anesthetic syringes.
- They must be durable to withstand repeated sterilization without damage.
- Disposable syringes should be packaged in a sterile container.
- They should be capable of accepting a wide variety of cartridges and needles of different manufacturers.
- They should be inexpensive, self-contained, lightweight, and simple to use with one hand.
- They should provide for effective aspiration and be constructed so that blood may be easily observed in the cartridge.
Syringe durability can be enhanced by following a routine of proper care and handling.
- After each use, thoroughly wash and rinse the syringe of any local anesthetic solution, saliva and other foreign matter.
- Autoclave the syringe as other surgical instruments.
- After every five autoclavings, dismantle the syringe and lightly lubricate all threaded joints and where the piston contacts the thumb ring and guide bearing.
- Clean the harpoon with a brush after each use.
- After extended use the harpoon will decrease in sharpness and fail to remain embedded within the cartridge stopper. Replace the piston and harpoon as necessary.
Even with proper maintenance problems may still arise.
- Bent harpoon – An off-center puncture of the rubber plunger may cause breakage of the anesthetic cartridge or leakage of the anesthetic solution.
- Dull harpoon – A dull harpoon may cause disengagement from the rubber plunger during aspiration.3