Ultrasonics is not for ‘dummies’

May 1, 2005
About 10 minutes before I graduated from dental hygiene school in 1971, I had my first experience with an ultrasonic scaler - a model 30 Cavitron.

About 10 minutes before I graduated from dental hygiene school in 1971, I had my first experience with an ultrasonic scaler - a model 30 Cavitron. It was big, old, and no one really knew how to use the antiquated-looking monster effectively. The tips were big, the handpiece was cumbersome, and water went everywhere. It’s hard to remember exactly what type of instruction we were given on the machine, but I don’t think it was much.

Hygienists who used ultrasonic scalers regularly in those days were scorned and given the derogatory name, Cavitron Queen. Our hearts told us that modern clinical practice revolved around proficient use of our skinny, gleaming hand instruments.

Times have changed. Tip designs have changed. Machines are more sophisticated and clinicians are more knowledgeable. Ultrasonic scaling is not a point-and-shoot activity, but a serious application of science. Whether someone uses a modern magnetostrictive unit or a contemporary piezo scaler is not the issue. The issue is what ultrasonics can do for our patients with respect to removing hard deposits, disrupting plaque biofilm, and increasing both patient and clinician comfort.

Jackhammer vs. feather duster

The thought of using an ultrasonic scaler exclusively or as the primary source of instrumentation is unnerving to many clinicians. The reasons they do not embrace these advancements are both legitimate and amazing.

Since I graduated 34 years ago, I respect how scary it can be to leave hand scalers behind. The technology, though, now allows ultrasonic scalers to provide patient care at a level we never dreamed possible.

If you have not had proper instruction on the use of ultrasonics, especially the newer, more adaptable units with the slimmer insert designs, using one would be like trying to drive a car without driver’s education. If you feel insecure about using a power scaler, then take a solid course with a hands-on component to learn about the advancements in ultrasonic technology.

Recent advancements in both magnetostrictive and piezo electric ultrasonic scalers are changing how we view contemporary scaling. Think about this analogy. Imagine taking a trip in a used Geo Metro with no air conditioning. Now imagine that same trip in a new Mercedes with all the creature comforts. This is how different hand scalers are from ultrasonic scalers. There are many brands on the market with a wide variety of features that determine clinical usage and the final clinical outcome for the patient.

All properly adjusted ultrasonic scalers will remove deposits to one extent or another, but the comfort level can be dramatically different. Newer, slimmer tips, designed for patient comfort, allow clinicians to access hard-to-reach areas. These designs allow hygienists to disrupt plaque biofilm in areas impossible to debride with a hand instrument, which results in a significant ergonomic benefit.

Sensitivity can be a serious problem. The size and diameter of the instrument tip has a profound impact on how ultrasonic scaling feels. The larger the tip diameter, the more potential for both hard and soft tissue discomfort. Slimmer tips create less tissue distention. Also, the force created by a large tip is greater than that of a slim tip. Think of a jackhammer versus a feather duster.

It is important to identify sensitive patients prior to scaling and to use products that can alleviate patient discomfort. There are a plethora of products that can eliminate or significantly minimize dentinal hypersensitivity. For years products that contained high levels of fluoride or potassium nitrate were the standard of care for treating root discomfort. New products have emerged, most notably ProClude, a desensitizing prophy paste that can significantly tackle this persistent clinical problem. Good post-scaling desensitizers are also available. These include various fluoride varnishes, fluoride gels, and special home care pastes.

The comfortable settings

Machines have varying power settings. Low power ranges are more comfortable for the patient and allow the clinician to use a slimmer tip. It may take more time to scale, but since patient comfort is a top priority, hygienists must be willing to spend more time with each patient. The dual stage power control device, available on current Dentsply ultrasonic scalers, offers extended low power ranges. By contrast, a conventional, automatically tuned magnetostrictive model does not provide the same adaptability.

Automatically tuned magnetostrictive ultrasonic scalers adjust the frequency to correlate with the power setting determined by the clinician. Some patients find automatically tuned units uncomfortable. These patients can often be treated with a manually tuned magnetostrictive scaler. The ability to change the relationship of frequency to power (amplitude) can allow manually tuned units to be used on patients who cannot tolerate ultrasonic scaling.

The amount of water or fluid used during ultrasonic scaling is a reflection of three phenomena - the type of unit, the diameter of the insert tip, and the ability to tune an insert out of phase. Fluid is used to cool and lubricate the tip, break up the biofilms with the cavitation mechanism of imploding bubbles, and provide washed field visibility. Some clinicians use liquids like chlorohexidine, fluoride or a povodone iodine solution as irrigants, but research has not demonstrated superior therapeutic benefits from these modalities.

In most cases, automatically tuned magnetostrictive units require more fluid than other units. Manually tuned units use considerably less fluid because less heat is generated in the stack when an insert is tuned out of phase. A simple adjustment of the frequency knob on the scaler alters the vibration pattern of the tip end. The result is a steady drip of water at the tip end, as opposed to a large halo of fluid generated by an automatically tuned unit. Typically, the fluid flow in manually tuned scalers becomes tepid, which is good for sensitive patients. Large diameter tips require more fluid than slim tips, which is true for either a magnetostrictive or a piezo unit.

Piezo electric ultrasonic scalers use crystals or ceramic discs that flex when energy is applied. This energy results in specific vibrations in the piezo tip. Magnetostrictive units use inserts composed of a stack of metal strips attached to an insert tip. When activated, these strips create vibrations that are transferred to the tip end. While both systems create vibrations at the tip end, piezo units do not generate a lot of heat. Although water is not needed to cool a piezo tip, it is very important for lubrication, washed field visibility, and disruption of plaque biofilm via the dynamics of cavitation. Piezo scalers typically use the same amount of irrigant as a tunable magnetostrictive unit. Either technology may be useful for treating geriatric or asthmatic patients due to reduced fluid flow and the reduced amount of aerosol that is generated by these scalers.

The tactile sensitivity from an ultrasonic is entirely different than from a hand scaler. Ultrasonic tactile sensitivity is a learned skill that increases with practice. It is dependent on the diameter of the insert, type of insert and proficiency of the clinician. Hygienists who use ultrasonics exclusively recommend an extraoral fulcrum and a light pen grasp on the scaler handpiece and all metal scaling inserts.

When challenged with industrial strength deposits, it is important to scale with a more powerful insert surface, increase the power setting on the scaler, choose a robust tip, and increase the frequency setting if using a tunable unit.

In my opinion it would be difficult, if not impossible, for most clinicians to put their hand scalers aside completely, but the tables are turning as the evidence mounts in favor of an ultrasonic scaler as our primary weapon against biofilm-based dental disease.

Ultrasonic scaling is not “Scaling for Dummies.” It is a sophisticated technology that can help us provide superior clinical care while saving our bodies from the ravages of repetitive stress injuries. Patti Beeson, RDH, summed it up: “One day you’ll be confident enough in your new skills to throw away the ‘crutch’ and trust the outcomes you are witnessing.”

We challenge you to experience the changes and create your new comfort zone.

Anne Nugent Guignon, RDH, MPH, is an international speaker, has published numerous articles, and authored several textbook chapters. Her popular programs include ergonomics, patient comfort, burnout, and advanced diagnostics and therapeutics. Recipient of the 2004 Mentor of the Year Award, Anne is an ADHA member and has practiced clinical dental hygiene in Houston, Texas, since 1971. You can reach her at [email protected] or (713) 974-4540 and her Web site is www.ergosonics.com.

The comfort of the tip

Understanding tip design and function is critical to providing maximum effectiveness, efficiency and patient comfort. Piezo tips work in a linear motion. The most effective clinical scaling with a piezo electric scaler is accomplished when the lateral surface of the tip is adapted to the tooth surface, which creates an erasure type motion. Magnetostrictive tips move in an elliptical or orbital path. All magnetostrictive tip surfaces are effective, however much more power is generated on the convex and concave surfaces.

Universal tips are designed to adapt to simple tooth anatomy. R&L configurations adapt to more complex clinical challenges like furcations, tipped or crowed teeth, severe lingual tilt, or fixed appliances. It is important to select the tip design that will allow maximum contact with the tooth surface. Worn-out tips or inserts need to be replaced, repaired or re-tipped. Inserts used in a manually tuned unit have a greater life span due to the ability to change the frequency along the length of the insert tip.

Since ultrasonics work via tip vibrations, it is critical for clinicians to use the lightest touch possible for optimal deposit removal (biofilm, stain and calculus) and enhanced tactile sensitivity. Applying the same pressure as with a hand instrument dampens the motion of the tip. A lighter touch increases clinician comfort and improves clinical outcome.

It is important to activate the insert prior to placing the tip on the tooth surface to improve patient comfort. Patients who are particularly sensitive to this technology can benefit from a variety of modalities, such as an application of a topical anesthetic agent, a locally delivered site-specific anesthetic, injectible anesthesia, or a patient-controlled pain modulation device. Some patients can overcome anxiety through professional coaching, premedication, external audio or video devices, or external relaxation devices such as chair mounted massage pads.