Most states that let hygienists administer local anesthesia allow both techniques — nerve blocks and infiltration.
But ADHA's chart, revised December 2025, shows four states limit hygienists to infiltration only: Alabama, New York, South Carolina, and Texas.
Virginia's entry carries a different condition — its chart cell reads "Both (Only on patients over 18)."
Here's what the two techniques are and where the limits apply.
The short answer
Where a state permits hygienists to administer local anesthesia at all, it almost always permits both techniques — nerve block and infiltration.
Per ADHA's Local Anesthesia Administration by Dental Hygienists chart, revised December 2025, only four of the 51 jurisdictions it tracks limit hygienists to infiltration only: Alabama, New York, South Carolina, and Texas.
A fifth, Virginia, carries a different condition — its chart cell reads "Both (Only on patients over 18)".
This article covers the technique distinction and where the infiltration-only limit applies.
Whether a state permits local anesthesia at all — and what supervision it requires — is a separate question; see the main local anesthesia article for that.
Verify with your state dental board
What's the difference between a block and infiltration?
Infiltration is the more limited technique: the anesthetic is deposited near the tip of the tooth's root, and it diffuses through the bone to numb that tooth and the surrounding soft tissue.
It works well where the bone is thin and porous — commonly the upper (maxillary) teeth — but it doesn't reliably numb a wider area.
A nerve block is deposited near a larger nerve trunk before it branches, numbing an entire region — a quadrant or a whole side of the jaw — rather than a single tooth.
Blocks are the technique typically needed for the lower (mandibular) posterior teeth, where the bone is too dense for infiltration to reliably numb through.
In practice, a hygienist limited to infiltration only can still numb most upper teeth and many procedures, but can't perform a mandibular block for the lower back teeth where one is usually needed.
Which states limit hygienists to infiltration only
Per the ADHA chart, four states restrict hygienists to infiltration and don't authorize the block technique at all:
- Alabama (authorized 2018)
- New York (authorized 2001)
- South Carolina (authorized 1995)
- Texas (authorized 2023)
Every one of those four also requires direct supervision — the dentist must be physically present when the hygienist administers anesthesia.
That pairing shows up in all four; the chart doesn't say whether the two are connected.
In every other jurisdiction the chart tracks, hygienists authorized to give local anesthesia may give both infiltration and block anesthesia once trained and, where required, examined.
The exception: Virginia's age-conditioned entry
Virginia isn't on the infiltration-only list — its chart cell for block and infiltration reads "Both (Only on patients over 18)".
That parenthetical qualifies the whole entry rather than naming which technique it applies to, so this article carries it exactly as written rather than assigning the age condition to block or infiltration specifically.
Virginia also requires direct supervision and 36 hours of combined didactic-clinical training.
It's the only entry of its kind on the chart — no other jurisdiction attaches an age condition to its block-and-infiltration cell.
Confirm the current rule, and exactly what it applies to, with the Virginia Board of Dentistry before relying on it.
What the infiltration-only limit means for your job search
If you're licensed — or considering licensure — in Alabama, New York, South Carolina, or Texas, know that your local-anesthesia scope stops at infiltration.
That doesn't block you from most periodontal procedures, but it does mean a dentist (or another provider authorized to give blocks) has to step in for cases that need one, most often deep scaling on lower back teeth.
If you're comparing dental hygienist jobs across state lines, that's one more scope difference to weigh alongside supervision level and course-hour requirements — a role that looks identical on paper can carry a materially different anesthesia scope once you check the state.
Ask before you relocate
How to confirm your state's rule
ADHA's chart is the best single reference for comparing states side by side, but your state dental board's practice act and administrative rules are the controlling authority.
If the two ever seem to disagree, the board wins.
If you're weighing a move, it's worth checking your target state's full local-anesthesia entry — the technique limit is only one column of a chart that also covers supervision level, required course hours, and whether an exam applies.
This article is general information, not legal or clinical advice. Scope-of-practice and licensing rules vary by state and change over time — confirm current requirements with your state dental board.