First, always check the carpule for cracks or suspended articles floating in the solution. If you find any, discard the carpule and notify the dental and dental supply to ensure other batches of anesthetic are usable. Disinfect the rubber diaphragm on the carpule before loading it in the syringe. Do not touch the rubber diaphragm after you disinfect it. Placing the carpule end in the aspirating syringe is fairly easy. Use the following steps:
Use the thumb ring to pull the plunger back against the syringe body.
Place the cartridge into the barrel of the syringe with the rubber stopper end in first, positioned toward the plunger.
Break the seal on the needle container and remove only a small portion of the plastic needle cover.
Insert the needle into the syringe and screw the hub onto the syringe.
Engage the harpoon into the rubber stopper of the cartridge by holding the body portion of the syringe with one hand while lightly tapping the end of the thumb ring with your other hand.
Do not tap the thumb ring with too much force; this might cause the glass carpule to shatter.
Make a quarter turn with the thumb ring to ensure that the harpoon is firmly engaged in the rubber stopper. If it is, the thumb ring will rotate back to its original position.
Force a small, but visible amount of anesthesia through the needle to expel air.
Loosen the needle cap, but keep the plastic needle covering in place until you pass the syringe to the dentist to guard against possible contamination.
The plastic needle cover must be removed to check the syringe's operation and during the injection.
The dentist will be ready to administer the local anesthetic after the topical anesthetic is applied. The assistant passes the syringe with the needle cover in place. Hold the barrel of the syringe in your hand. Place the thumb ring of the syringe over the dentist's thumb and the finger grip between the dentist's index and middle fingers. While you are still holding the syringe by the barrel, use the other hand to remove the needle cap.
After the dentist gives the injection, carefully remove the syringe by grasping the barrel and lifting the syringe out of the dentist's hand. Remember to exercise extreme caution when grasping the barrel of the syringe because the needle is exposed and contaminated. DO NOT attempt to recap the needle while the syringe is in the dentist's hand. If it is necessary to recap the needle, it must be done using some type of mechanical device or the one-handed scoop technique discussed in Volume I, Chapter 9, "Infection Control."
After the patient is dismissed, the syringe must be disassembled safely. It is vitally important to prevent needle sticks from the contaminated needle. It is advisable to first remove the carpule with the needle remaining in place. This provides an air vent to prevent the glass carpule from shattering. To unload the carpule, pull the piston rod back as far as possible to disengage the harpoon from the rubber stopper without pulling the stopper from the carpule. The carpule can then be easily removed from the syringe. Remove the used needle and dispose of it into a puncture-resistant container according to established infection control standards.
Immediately after the dentist administers the local anesthesia, you will irrigate and aspirate the injection site. This is necessary because the anesthetic solution produces a bitter taste in the patient's mouth. Additionally, you are required to irrigate and aspirate (drawn by suction) often throughout the treatment procedure to maintain a clean treatment site.
The dentist expects you, as the dental assistant, to irrigate the oral cavity when necessary. By applying water or saline solutions to the treatment site in the oral cavity, small tooth particles, dried blood, and other debris are flushed from the area and removed by aspiration. Handpieces with water spray systems provide some irrigation, but additional irrigation is always necessary. At times, the dentist may decide not to use the water spray system on the handpiece for a particular procedure. During routine operative procedures, you will use the three-way syringe on theContinue Reading