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Updated: Jun 24, 2023

It’s time to celebrate!


Because more states have expanded the scope of practice for dental hygienists to include the administration of local anesthesia. At the time of writing Delaware is the only that doesn't allow dental hygienists to pick up the syringe and anesthetize a patient. Washington and Oregon were the first states to expand the scope of practice for hygienists in the early 1970’s. It is my hope that the last three states bring this benefit to the operatory.

With more hygienists giving injections, I am often asked which ones should be locked, loaded and ready to go for our patients. It’s hard to narrow it down to just a few, as each type of injection has it’s time and place for patient care. But if someone wants to focus on mastering a handful here are my top six injections every dental hygienist should know. I chose these because they will work for a variety of patients no matter if it’s for non-surgical perio therapy or restorative care.


infiltration technique

The first and most simple injection is the infiltration technique also called the supraperiosteal injection. The infiltration technique is designed to anesthetize a single tooth (pulp and surrounding gingiva). These are mainly done from the facial aspect at the height of the mucobuccal fold and the anesthetic is deposited at the apex of the root. If there is a procedure in which the lingual tissue is highly sensitive or if there is cross-over innervation a lingual or palatal approach can be used. For hygienists in Alabama, New York, and South Carolina this is the only type of injection they can perform. This is unfortunate, as it requires multiple injections and more anesthetic than needed. Ideally, this injection approach is best for anesthetizing a single tooth.


nasolabial groove

The PSA is one of the main injections every clinician should have mastered. This injection will anesthetize the pulps of the maxillary molars and the associated facial structures.

I consider the PSA geometry in motion because it’s all about moving the syringe to gain the correct angles. The challenge of getting the 45 degrees away from the midline and 45 degrees away from the maxillary occlusal plane., can make you feel like you are trying to thread a tiny needle, in the dark, and only by feel. That’s probably why it’s one of the injections board examiners use to assess the qualifications of a hygienist’s ability to perform injections.

Using the nasolabial groove makes a great external landmark to help you align your barrel. The beauty of this landmark is when the syringe is parallel to it your angles will fall in place.


IA site of insertion

Speaking of anesthesia board exams, the IA is the other injection analyzed to see if hygienists have the skills necessary to inject someone safely. This is probably the most popular mandibular block used in dentistry and the one which causes clinicians the most trouble too. When correctly done the IA numbs the pulp of the entire mandibular quadrant (of the side injected). However, it does not take care of the facial tissue of the molar region. This is important to remember because a follow-up long buccal injection may be needed. When done correctly it is relatively easy to give. The error I see most often is the clinician inserting the needle too low along the ramus of the mandible. When this happens, the anesthetic solution ends up below the mandibular foramen. The patient’s tongue might lose sensation, but the pulps of the teeth will not be affected. To correct this simply look for the Linea Alba (bite line). When the patient opens wide, this landmark creates a great leveling line for your needle insertion.


Gow-Gates Injection Site

The Gow-Gates is my favorite mandibular block because it is highly reliable, and the patient can achieve profound anesthesia. The reason is because the G-G bathes the mandibular nerve higher along the ramus of the mandible, which means there is a greater likelihood to anesthetize the long buccal nerve which innervates the facial tissue of the molar region and the mylohyoid nerve which can cause cross over innervation to the mandibular 1st molar. The drawback to this injection is the patient needs to keep their mouth open wide during the injection and for a few minutes after. When first learning this injection patience is required due to a steep learning curve.



Popping back upstairs to the maxillary teeth we need to think about the rest of the quadrant other than the molars, right? The AMSA injection is a dream! This palatal approach anesthetizes so many structures. With just one shot your patient will have the pulps of the premolars through the midline anesthetized. Plus, the entire palatal tissue of the side injected and the facial tissue from the premolars to the midline. The bonus of this injection is your patient keeps complete sensation and function of the upper lip, and it does not affect the nose either. (This means your patient won’t feel like they have stuff hanging out of their noses)

Many clinicians did not learn this injection while in school. Probably because it has only been about 20 years since it’s been part of mainstream dentistry. And many clinicians tend to shy away from giving palatal injections. But if you use pressure anesthesia your patient won’t bat an eye.


IO Injection

Let the “I’s “have it…I can’t decide if the IO or the Incisive should be number 6. So maybe they are tied…These two injections or mirrors of each other. They both take care of the premolars to the midline. The IO is for the maxilla and the Incisive is for the mandible. The key to both is to deposit the solution over the foramen and massage the anesthetic in. The incisive is great when you need premolar to premolar without lingual tissue. The IO is just the same and is a great choice for those who are leery of the palatal approach. The main thing to remember with the IO is the patient will achieve anesthesia on the cheek, nose, and lip.

There are many more injections clinicians should be willing to implement when needed. When I first sat down to write this, I originally thought I’d give you my top four or five. Obviously, that didn’t work, since I basically discuss seven different injections. No matter which injections you choose to use on a regular basis I encourage you to create some time and take a refresher course on anesthesia which includes techniques to buff up your syringe slingin’ skill set. There are several options out there including my online course HIT ME WITH YOUR BEST SHOT.

Keep those syringes safe and happy injecting!


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