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local anesthesia in dentistry

Local anesthesia: Our savior and our nemesis

Dec. 11, 2024
Local anesthesia is, unfortunately, a necessary part of dentistry, and it’s a focal point in almost every appointment. Dr. Neville Hatfield shares tips on how he virtually eliminates the discomfort associated with local anesthesia and reaps the dividends.

As we all know, patient experience is the single most important factor in driving new-patient growth. You could have the best marketing strategy in the world, but you will fall short of your growth goals without word-of-mouth referrals or positive online reviews. One of the most effective ways I’ve improved patient experience is by updating my anesthetic delivery technique.

I used to rely on humor to diffuse patient tension and anxiety, and while I still do to some extent, I realized that anxiety often stems from the fear of injections or the noise of dental handpieces. While we can reduce handpiece noise by using electric handpieces or offering headphones and earplugs—and even invest in expensive dental lasers for cavity preparation without anesthesia—we often need to find more accessible methods to alleviate the anxiety associated with local anesthesia.

Since we cannot easily avoid administering local anesthesia in our work, we must be deliberate in our injection techniques. While some small carious lesions may not require anesthetics, they do not make up a significant portion of my restorations. However, by slightly adjusting my technique and investing in a more cost-effective armamentarium, I’ve significantly changed my patients’ expectations regarding uncomfortable dental experiences. This has led to a marked increase in word-of-mouth referrals. I jokingly refer to myself as having “magic hands” when patients exclaim that they felt nothing during the anesthesia process. Each dentist’s technique can vary greatly, and not every method works for everyone, but along the way, I’ve gathered and implemented several tips, tricks, and tools that work for me.

No. 1: Leveraging the “gate theory of pain”

My first tip is widely taught—the “gate theory of pain,” which involves using nonpainful stimuli to close the nerve “gates” to painful stimuli. This can be done by shaking the lip or cheek or quickly moving the tissue near the injection site. This serves as both a distraction and a way to shift the patient’s focus from the injection. I typically use my hand mirror to stimulate the tissue, but I’ve also used the VibraJect from GoldenDent, which I’ve found to be an incredibly effective tool for taking advantage of the “gate theory of pain.”

No. 2: The “air” instrument technique

My second tip comes from one of my attending pediatric dentists in dental school. Although I generally reserve this technique for severely anxious patients, I find it helpful in almost every instance I use it. This method also likely leverages the “gate theory of pain.” When I identify a severely anxious patient, whether through their admission or my observations, I ask if they’ve ever played a musical instrument. If they have, I encourage them to pretend to play that instrument, like an “air” guitar or piano, in time with the music playing in my operatory while I administer the anesthetic. For those not interested in playing music, I suggest they pretend to type out, “I hate the dentist and I’d rather be anywhere else,” on an “air” keyboard. This humorous approach helps diffuse the situation and shifts their focus away from the injection.

No. 3: Proper use of anesthetic gel

My third tip is to always thoroughly dry the injection area with a 2x2 gauze before applying a numbing gel. These gels, which typically contain benzocaine, only numb the most superficial soft tissue. However, patients expect them, and I find their use beneficial, though they may act more as a placebo. The reason for drying the tissue is that the gel can slide around on moist mucosa, sometimes ending up in the patient’s throat and causing complaints of a numb throat. The 2x2 gauze helps to dry the tissue, holds the gel at the injection site, and keeps the tongue away from the gel.

No. 4: The importance of a sharp needle

My fourth tip is to switch to a new needle if you need to puncture the tissue more than three times. Each puncture dulls the needle, requiring more force and causing less “cutting” of the tissue, leading to discomfort. Needles are inexpensive, and swapping out a dull needle, even if you haven’t finished the carpule of anesthetic, can build goodwill with your patient.

No. 5: Investing in a computer-aided anesthetic device

My fifth—and probably most important—tip is to invest in a computer-aided anesthetic device. Specifically, I use the Calaject from Directa Dental, which I’ve found to be the most versatile and cost-effective unit available. This device dispenses local anesthetic at a controlled flow rate, using the back pressure from the anesthetic to allow for precise and pain-free injection. Most of us know that the pain from an injection comes from adding liquid volume into a space that cannot expand to accommodate it. Calaject’s design follows scientific recommendations for the speed and pressure of anesthesia administration, ensuring a pain-free and comfortable experience for patients.

The Calaject system is designed to replace traditional injection techniques. It consists of three components: the main module with a long-lasting rechargeable battery and easy-to-clean control panel, a small foot pedal that connects to the main module, and a pen-shaped handpiece that eases anxiety by replacing the traditional dental syringe. The handpiece features a clear, autoclavable barrel that holds the anesthetic cartridge and needle, and it also has an auto-aspiration feature that prevents anesthetic from leaking where it’s not needed. The system offers three separate modes for intraligamental/palatal injections, infiltrations, and regional blocks, along with a prominently featured pressure gauge, which is critical for live feedback during PDL/palatal injections.

With all these features, Calaject has been a key component in transforming how I administer anesthesia in my practice. The feedback I receive from patients consistently highlights the difference in comfort compared to traditional syringes, making Calaject a crucial element in improving patient satisfaction.

While there are many other techniques I haven’t mentioned, it’s essential for us to invest in the knowledge and equipment necessary for pain-free dental injections. Local anesthesia is, unfortunately, a necessary part of our work, and it’s a focal point in almost every appointment. However, by virtually eliminating the discomfort associated with local anesthesia, you will undoubtedly see dividends in the form of increased patient referrals, better online reviews, and overall enhanced patient trust and satisfaction. 

Editor's note: This article appeared in the November/December 2024 print edition of Dental Economics magazine. Dentists in North America are eligible for a complimentary print subscription. Sign up here.

About the Author

Neville T. Hatfield, DMD

Neville T. Hatfield, DMD, graduated magna cum laude from the Boston University School of Dentistry. He completed a general practice residency at the Manhattan Veteran Affairs Hospital, where he provided interspecialty comprehensive prosthetic and surgical treatment to medically complex patients. When he is not treating patients in northern New Jersey, he enjoys lecturing about dental materials and products.

Updated April 7, 2023