A dental block is a nerve-numbing injection used before lip filler to eliminate pain during the procedure. Instead of numbing just the surface of the lips, a dental block delivers anesthetic deep into the tissue near specific nerves, blocking all sensation to the lips and surrounding area for several hours. It’s the same type of injection a dentist gives before a filling, repurposed here for cosmetic use.
Not every practitioner uses a dental block for lip filler. Many prefer topical numbing cream or rely on the lidocaine already mixed into most modern fillers. Whether a dental block is right for you depends on your pain tolerance, your injector’s technique, and the tradeoffs you’re willing to accept.
Which Nerves Are Targeted
Lip filler dental blocks target two main nerves, one for the upper lip and one for the lower. The infraorbital nerve supplies sensation to the upper lip, the side of the nose, and the lower eyelid area. The mental nerve handles the lower lip, the chin, and the inner lining of the lower mouth. It branches off the inferior alveolar nerve, which runs through the jawbone and exits through a small opening called the mental foramen, located roughly below the premolar teeth.
To numb both lips completely, your injector needs to block both nerves on both sides of the face, meaning up to four separate injections before the filler itself. For the lower lip, the needle is placed near the mental foramen along the jawline. For the upper lip, it’s directed toward the infraorbital foramen just below the eye socket. Each injection deposits a small amount of anesthetic right next to the nerve, shutting down signal transmission from that entire region.
What the Injection Feels Like
The dental block itself involves a brief sting as the needle enters, followed by a feeling of pressure as the anesthetic is deposited. Most practitioners use lidocaine, often in a 2% concentration combined with a small amount of epinephrine to constrict blood vessels and keep the numbing effect localized. Some use articaine, which diffuses through bone tissue more effectively and comes in a 4% concentration.
Numbness typically sets in within one to three minutes. Once the block takes effect, you won’t feel the filler injections at all. The tradeoff is that the numbness extends well beyond the treatment itself, usually lasting two to four hours, though it can persist longer depending on the anesthetic used. Bupivacaine, a longer-acting option occasionally used in dental settings, can keep tissue numb for four to nine hours.
Why Some Injectors Avoid It
Dental blocks come with a set of practical downsides that make many experienced filler injectors prefer other options. The biggest concern is tissue distortion. The volume of anesthetic fluid injected near the nerves can cause subtle swelling in and around the lips. When the lips are swollen and completely numb, it becomes harder for the injector to judge symmetry, shape, and volume in real time. Muscle function in the lip area can also be temporarily affected, causing a drooping or uneven appearance that masks the true result. Some patients end up needing a touch-up appointment once the block wears off and the final shape becomes visible.
There are also additional risks from the block injections themselves. More needle entry points mean more opportunities for bruising, swelling, and post-procedure soreness. In rare cases, a dental block can cause temporary or prolonged nerve irritation, or a small blood collection called a hematoma at the injection site. For practitioners who aren’t trained dentists, the reliability of the block depends heavily on technique. Missing the nerve target by even a few millimeters can result in incomplete numbness, requiring a second attempt.
The prolonged numbness also creates practical problems after you leave the office. With lips that can’t feel temperature or pressure, you risk burning yourself on hot drinks, biting your lip without realizing it, or having difficulty eating, drinking, and speaking normally. Drooling is common while the block is active.
Alternatives to a Dental Block
Most filler practitioners today use one of two simpler approaches, either alone or in combination.
- Topical numbing cream: A lidocaine-based cream (often 4% or 5%) is applied to the lips 15 to 20 minutes before the procedure. It numbs the surface tissue enough to take the edge off the needle pricks without affecting deeper sensation or distorting the lip shape. The numbness fades relatively quickly after treatment.
- Lidocaine in the filler: Most hyaluronic acid fillers sold today contain 0.3% lidocaine mixed directly into the gel. As the filler is injected, the lidocaine numbs the tissue from the inside, so each subsequent injection point hurts less than the one before. Combined with a topical cream applied beforehand, this is enough for most patients to tolerate the procedure comfortably.
Lip filler injections are not painless with these methods, but the discomfort is brief and manageable for most people. The sensation is typically described as a series of quick pinches and some pressure, lasting 15 to 30 minutes total.
When a Dental Block Makes Sense
Some patients have very low pain tolerance or significant anxiety around needles, and for them, a dental block can make the experience far more manageable. Certain procedures that involve larger volumes of filler or more extensive reshaping of the lip border may also benefit from deeper anesthesia. If you’ve had lip filler before and found it too painful with just topical cream, a dental block is a reasonable option to discuss with your injector.
The key is working with someone who performs nerve blocks routinely and understands how the temporary swelling and muscle relaxation will affect the final result. Practitioners with dental training or significant experience with facial nerve blocks can compensate for the distortion and plan their filler placement accordingly. If your injector offers a dental block, ask how they account for the tissue changes it causes and whether they typically need follow-up appointments to adjust symmetry.