3 Reasons Why You’re Not Going Numb

One of the most common worries people have when visiting a dentist is that the anesthetic won't work and they will experience pain. While the majority of these concerns are due to anxiety, there are some rare scenarios where the effectiveness of local anesthetic is reduced.

Overactive Nerve Endings

Local anesthetic injected into the mouth will always work if it is supplied in the correct spot. However, the location of this spot can vary widely between patients and some people may have such an unusual setup that the standard procedure adopted by dentists doesn't work.

With that said, this is extremely rare and there is likely another explanation for why you aren't feeling the effects of anesthetic. In many cases, the problem stems from a collection of overactive nerve endings that supply the feeling to the tooth. These nerves are extremely sensitive, so having more than the average person can ramp up the pain experienced when undergoing treatment.

However, dentists understand this condition well and are able to take steps to reduce your discomfort. If your dentist suspects that you have overactive nerve endings, they can inject a highly localized shot of anesthetic to block these nerves from feeling pain. This anesthetic aims to freeze the path running from the nerves, which in turn will stop them signalling to your brain that they are experiencing pain.


If you are currently suffering from a localized infection then a regular dose of anesthetic may not be enough to numb your mouth entirely. This problem is most common in patients with abscesses, as these abscesses typically indicate a highly concentrated area of infection. This infection acts to alter the pH level of the surrounding tissue which can cause the area around the abscess to become acidic.

Local anesthetic is highly dependent on the pH level of its surrounding environment and acidic environments are very good at negating the effects of the injection. Specifically, the acidic environment slows down the movement of the anesthetic to a near halt, such that the medication is unable to reach the required areas in time.

Thankfully, ramping up the level of local anesthetic applied can help this condition. By saturating the surrounding area with medication, the infection present in your mouth becomes overwhelmed and the local anesthetic can get to the right locations prior to treatment.

If you know of an abscess that may cause some trouble to the medication, speak to your dentist prior to having the injection administered. Dentists understand the relationship between infection and anesthetic, so letting them know of any existing condition will allow them to up your dosage.

Ehlers-Danlos Syndrome

If your dentist has taken all possible steps to get you numb but isn't getting anywhere, it could be due to an underlying medical condition. Specifically, patients with Ehlers-Danlos syndrome can find it difficult to "get numb" when treated with local anesthetic.

Ehlers-Danlos syndrome is a condition that affects the mobility of joints and connective tissues. The most common sign in suffers of Ehlers-Danlos is the presence of hypermobile joints. Many children have hypermobile joints, which is where the joint is able to move beyond its normal range of motion. If this continues into adulthood however, it could be a sign of Ehlers-Danlos syndrome.

There is evidence to suggest that patients with Ehlers-Danlos have a high resistance to local anesthetic. With that said, dentists can help these patients by using a long-lasting variant of local anesthetic that also narrows the blood vessels.

If you believe that Ehlers-Danlos syndrome could be the cause of your problem, speak to your dentist or a place like Schererville Family Dentistry, PC about what can be done. Typically, your dentist won't administer a long-lasting anesthetic without good reason, so it's important to make them aware of any condition that may merit a stronger medication.