Development in Local Oral Anesthesia

By Rebecca Stone February 26, 2019

Pain control is probably the number one concern of patients dropping into a dental chair. But the irony is that the very thing that helps eliminate pain, also inflicts it momentarily. And patients may be more fearful of that local injection than they are of any actual dental pain.

But a trip to the dentist needn’t be a white-knuckle affair. Advances in anesthesia have taken aim at reducing the fear and pain on many fronts. 

Local Anesthesia Delivery

Slow delivery is recognized as the least painful way to administer a local injection. But innovations abound. One method of delivering painless injections involves the use of vibration. A battery-operated device, clipped onto a syringe, produces a mild vibration. The brain senses the vibration and doesn’t feel the prick of the needle.1

Another method employs transcutaneous electrical nerve stimulation via a small, battery-powered electronic device. The electrical stimulation emitted appears to interfere with pain signals between nerves and the brain. It may be most helpful as an adjunct for local anesthesia.2,3

An additional strategy has to do with the formulations. Because solutions such as lidocaine tend to be highly acidic (low pH), they can sting when injected into human tissue, which has a higher pH. To combat this, sodium bicarbonate can be added to the mix as a buffering agent. Buffering raises the pH, reducing pain during injection. It can also save time via faster uptake, and has become available as a computer-controlled system.1

A further innovation is a delivery device that helps clinicians keep track of how much anesthetic they’re drawing or injecting by emitting a click per milliliter.

The design of the needles themselves offers another avenue toward less painful injections. In one product, needle tips are beveled on three sides, feature siliconized canulas, and slide through tissue without pulling. 1

Needleless Innovations

Other advances don’t involve needles at all. For instance, in 2016, the U.S. Food and Drug Administration approved a tetracaine-based nasal spray. Offering needleless local anesthesia, the spray has been shown to be safe and effective in maxillary tooth restorations.1,4

Other needleless options are also available, including a lidocaine/prilocaine periodontal gel that’s applied subgingivally via a blunt-tipped applicator. Another features a cannula that can be slipped into the sulcus to apply anesthetic across the periodontal ligament for rapid, single-tooth anesthesia.1

Efforts are also underway to develop local anesthetics whose effects would last for possibly 2 or 3 days. Without the need to combat post-op pain, patients would not need to resort to highly addictive opioids.5

Enhancing Safety and Comfort

Pre- and post-operative measures can be taken to enhance patient comfort. These include application of topical anesthetics prior to injection, and application of a reversal agent to shorten the duration of anesthetic effects once treatment is completed. Nitrous oxide is another strategy that can take the edge off injection anxiety by inducing a mild sense of euphoria during treatment.

No matter which strategy you use to provide your patients with the least painful injection possible, it’s good to know that you can further extend the comfort factor with the use of systems such as Isolite. Not only will it relieve jaw fatigue by serving as a bite block, but it shields the throat from foreign objects, and provides continual suction and superb traction, all while illuminating the field of operation.

Dentists who can keep their patients comfortable score high with them. And overall, that’s good for business.



  1. Stone R. Stop feeling the burn. Mentor. 2016;7(12):26–28,30–31.
  2. Electronic Dental Anesthesia. Available at: Accessed December 21, 2018.
  3. Kasat V, Gipta A, Ladda R, Kathariya M, Saluja H, Farooqui AA. Transcutaneous electric nerve stimulation (TENS) in dentistry–a review. J Clin Exp Dent. 2014;6:e562–e568.
  4. Penn Today. Penn Study Finds Nasal Spray Effective and Safe Anesthesia for Dental Work. Available at: Accessed December 21, 2018.
  5. Moore PA. Innovations in local anesthesia are easing the pain of dentistry. Compend. 2018;39:256–257.