The Dentists Asked for It By Trisha E. O’Hehir, RDH, BS, Editorial Director, Hygienetown Magazine

Now an integral part of dental hygiene practice, local anesthesia was taught to dental hygienists in several demonstration projects in Pennsylvania, Iowa, Massachusetts, and Washington, DC nearly 40 years ago. In 1971, The state of Washington was the first to change the law, thus allowing licensed dental hygienists to legally administer local anesthesia. The idea originated within the dental association and was presented to Dr. Martha Fales, then director of the Dental Hygiene Program at the University of Washington.

The dentists proposed local anesthesia and restorative functions for the dental hygienist and wanted educational support before seeking a law change to include these procedures in the scope of practice for dental hygienists. Dr. Fales, a dental hygienist herself, assured the dental association officers that her department could teach these skills to hygienists. With that support, the dental association moved forward to change the law.

Today, 40 states include local anesthesia in the scope of practice of the dental hygienist. Despite evidence to the contrary, some state dental boards still fear that incorporating local anesthesia into the practice of dental hygiene will lead to independent practice for hygienists and probably patient death. However, in my experience, dental hygienists licensed to administer local anesthesia free the dentist to perform more profitable procedures. After nearly four decades of dental hygienists administering local anesthesia, it is clear they are not only capable and safe, but also a valuable asset to the practice. Dental hygienists licensed to provide local anesthesia use their skills for both their patients and the dentist’s patients. It’s only a matter of time before the remaining 10 states bring the practice of dental hygiene in their states up to the established standard by including local anesthesia for dental hygienists in their laws.

Over the past 35 years, injections and the equipment to administer them have changed. Today, hygienists have a wide variety of anesthetics, syringes, syringe products, topical anesthetics, and even new injections from which to choose. If you are already licensed to administer local anesthesia, you’ll find these product and technique advances helpful. If you work in a state that has yet to change the practice act, your options also have broadened to include more topical anesthetics, some replacing injections.

SYRINGES

In the 1970s, dental hygienists used a standard stainless-steel harpoon syringe. Today the range of syringes includes self-aspirating, designs for small hands, lightweight materials, pressure syringes for interligamental injections, a needleless syringe and two computer-regulated syringe systems.

Self-aspirating syringes were my choice in the past because pulling back on the thumb ring to aspirate is awkward with a standard harpoon syringe. Today, petite syringe designs from Septodont, Miltex and Hu-Friedy fit the smaller hands of women, providing greater needle control while aspirating. I'm sure the future will bring petite syringes with the self-aspirating feature.

The pressure syringe was introduced in the late 1970s, providing an option for the periodontal ligament injections. The needle is inserted into the sulcus like a probe, and then inserted into the periodontal ligament. This technique allows for pulpal anesthesia of a single tooth. It’s ideal for extraction of deciduous teeth or periodontal treatment on a single tooth. The early designs were trigger operated, depositing the anesthetic solution with pressure (Resista Peripress and HSW Ligmaject). The newer designs are highly refined, sleeker, and allow the clinician to easily and comfortably deposit the anesthetic solution a drop at a time. The sleek pen design reduces patient anxiety associated with viewing a syringe. The Citoject syringe from Heraeus angles the needle for easier insertion and although the Paroject from Septodont is a straight syringe now, future designs will include an angled needle hub. These syringes also are used for palatal and papillary injections. Consider putting one of these syringes on your dental hygiene department shopping list.

Technology has reached the field of local anesthesia. Two computer-assisted injection systems are now available. These systems electronically control the flow of the anesthetic, to assure a slow, comfortable injection for the patient. New injections have been described specifically for these systems.

The Milestone Scientific CompuDent delivery system with the Wand handpiece was developed to control the delivery of a preset amount of local anesthetic agent, avoiding rapid injections and providing a more comfortable experience for patients. The Wand is held much like a pen, which is more comfortable for the clinician than a standard syringe and less intimidating for the patient. The Wand was the first computerized injection system, followed by the Dentsply Midwest Comfort Control System.

SYRINGE ADJUNCTS

Do you “wiggle and jiggle” the tissue at the site of injection to distract the patient and trick the mind into recognizing the vibration of “wiggle and jiggle” – not the sensation of pressure associated with the injection? Now, there’s a battery-operated attachment for the syringe that does the “wiggle and jiggle” for you. The ITL Dental VibraJect was invented by oral surgeon, Dr. Norman Pokras and dental products inventor Ron Coss. This battery-operated, vibrating motor attaches directly to the syringe, providing vibrations to reduce the patient’s perception of the needle being inserted.

To adapt standard syringes to smaller hands, Eva Stadick, RDH, designed and patented a thumb ring reducer that fits right in the thumb ring of standard syringes. This simple, yet clever plastic ring will slip into the thumb ring on the syringe, reducing the size and ergonomically adapting the syringe for comfortable administration of injections. Eva’s patented thumb ring is not yet in production, but is available to companies interested in licensing the patent.

ANESTHETIC AGENTS

To the public, all injections are Novocain. Although procaine, the generic name for the trade name Novocain (which means new and cocaine), was the first injectable local anesthetic, it hasn’t been used alone for many years. It isn’t a particularly effective agent, since it provides no pulpal anesthesia and only 15-30 minutes of soft-tissue anesthesia.

In the 1970s, hygienists used primarily lidocaine with and without vasoconstrictor and occasionally mepivacaine or prilocaine. Since then, many new anesthetic agents have been introduced and new ones are in the works. The newest is articaine (known as carticaine prior to 1984). It was used in Europe and Canada long before becoming available in the US. Articaine is fast becoming the favorite of dental hygienists due to quick diffusion through tissue, thus achieving profound anesthesia. Some report that fewer palatal injections are needed when infiltration is done on the facial surfaces, as diffusion to the palatal is sufficient for instrumentation.

TOPICAL ANESTHETICS

Topical anesthetics were designed to numb the site prior to inserting the needle. They come in gels, liquids, sprays and patches. Becker-Parkin, Sultan Dental and others offer individually wrapped, presoaked, premeasured, topical anesthetic swabs.

New to this class of products is the introduction of topicals to replace injections. It started with DentiPatch, a transoral lidocaine delivery system created in 1996 by Noven Pharmaceuticals, Inc. The patch combines lidocaine and an adhesive and is placed on mucousal tissue like a Band-Aid prior to an injection or to achieve soft-tissue anesthesia, allowing for subgingival instrumentation. Onset is 15 minutes and duration 35-45 minutes.

Oraqix from Dentsply Pharmaceutical is the only topical combined with a polymer. When delivered into a pocket, body temperature changes it from a liquid to a gel for longer-lasting anesthesia. Onset of action is 30 seconds and it provides 20 minutes of anesthesia for periodontal instrumentation in pockets 5 mm or less. Each carpule of Oraqix provides enough gel for one quadrant.

Topical anesthetic can be delivered to subgingival areas prior to instrumentation. Liquid agents can be drawn up into a syringe for subgingival delivery; examples are Cetylite Industries, Inc. Cetacaine, Beutlich LP Pharmaceuticals Hurricane and Sultan Dental Topex liquid. There also are preloaded syringes, such as Ultracare available from Ultradent.

Selecting your favorite topical is based on patient acceptance of flavor and the rate of onset you achieve. No studies have been reported comparing various liquid topical agents used subgingivally. The decision is up to you.

INJECTION TECHNIQUES

Thirty years ago, the standard block injections included: the inferior alveolar, lingual, posterior, middle as well as anterior superior alveolar and the infraorbital. Three new injections have been introduced to provide better anesthesia in difficult areas. The Gow-Gates injection was developed in Australia to anesthetize both maxillary and mandibular teeth and tissue. Check out the free Hygienetown online CE courses for video demonstrations of these injections.

The introduction of the Wand brought with it two new injections, the anterior middle superior alveolar (AMSA) block and the palatal anterior superior alveolar (PASA) block. The AMSA anesthetizes the soft tissue from the central to the second premolar both palatal and facial. The PASA anesthetizes maxillary incisors, cuspids, anterior third of the palate and the anterior facial gingiva. Using the computerized syringe with slow, pressure-driven delivery of the anesthetic agent, these block injections are comfortable for both clinician and patient.

Conclusion

The Washington State Dental Association asked for local anesthesia and restorative funtions for dental hygienists to help dentists with the high patient demand they faced in the early 1970s. Shortly thereafter, the US government offered dental schools grant money to build new dental schools if the schools agreed to double student enrollment. This action flooded the market with dentists who experienced a shortage of patients, and thus support shifted away from allowing hygienists to administer local anesthesia. This is reflected in the pattern of anesthesia law changes. In just seven years, from 1971 to 1978, eight states followed Washington’s lead and changed laws to include local anesthesia for dental hygienists. It took 17 years for the next eight states to change the law. Since 1995, 23 states have changed their laws to include local anesthesia. The pendulum is beginning to swing back to an era of fewer dentists and increased patient demand. This bodes well for the remaining 10 states. When dentists in those 10 states realize the value of hygienists administering local anesthesia, they too will rally to change the laws.