The power of ultrasonic inserts

June 1, 2006
Most jobs require correct tools. It is important to know when, why, and how to use the proper implement.

Most jobs require correct tools. It is important to know when, why, and how to use the proper implement. Imagine trying to make a cake without a mixing bowl, plant a rose bush without a shovel, or sew a garment without thread.

While these comparisons may seem quite exaggerated, hygienists often try to perform miracles with power-driven scalers without having an insert that is truly appropriate for the task. It takes a variety of specially designed instruments for a dentist to fabricate beautiful, natural tooth-colored restorations. The same is true for fully integrating power-driven scalers into our dental hygiene treatment rooms.

Each patient has a unique set of clinical challenges. No one wants to scale the entire mouth with only a 6/7 anterior sickle instrument. It is just not possible to access all areas of the effectively with one type of hand instrument. While this analogy is not completely transferable to power scaling tips, it is important to understand the intricate details of ultrasonic scaling tip designs.

Contemporary ultrasonic insert tips are quite adaptable, but we need more than just universal inserts to integrate ultrasonic scaling fully into daily practice. Our armamentarium should include appropriate tips to fulfill a wide range of clinical challenges.

Let’s review a few basic concepts and then discuss the benefits, limitations, and clinical application of various tip configurations.

Your choice on the engine

First, there are two basic types of ultrasonic generators: Magnetostrictive and piezoelectric. Magnetostrictive is the predominant technology in North America today; however, the exact opposite is true in the rest of the world.

It is strictly a matter of personal clinical preference, similar to one’s preference automobiles. Some people drive cars with combustion engines. Others prefer diesel powered automobiles. You can arrive at your desired destination in either type of vehicle.

All surfaces of both magnetostrictive and piezoelectric ultrasonic scaling tips are active. In other words, any surface of any ultrasonic insert has the capacity to remove hard deposits and disrupt plaque biofilm when an activated insert comes in contact with deposits. The effectiveness and efficiency of ultrasonic scaling is further dependant on the specific tip surface, the length of time the insert is in contact with the tooth, and the size and configuration of the tip.

The lateral surfaces of a magnetostrictive insert are the most gentle. One should begin scaling with the lateral surface. Often there is sufficient power to remove light to moderate deposits with the lateral surface. If deposits are tenacious or heavy, reposition the insert on the tooth using either the convex or the concave surface. Avoid using the point of any insert tip on delicate tooth structures.

These lateral surfaces of a piezo tip produce the smoothest, quietest vibrations, but, again just like a magnetostrictive insert, one can disrupt deposits with the convex and concave tip surfaces.

Given proper adaptation and sufficient time, it is possible to disrupt plaque biofilm and hard deposits by adapting different sides of ultrasonic tip to various tooth surfaces. Ultrasonic scaling is not necessarily faster, but it does have the potential, if used properly, to enhance deposit removal and facilitate biofilm disruption.

Motions of inserts

With the exception of one unit, the tip on a magnetostrictive insert moves in an elliptical figure-eight path. Inserts reposition easily in the handpiece to accommodate various tooth surfaces.

Piezo electric tips have a linear erasure-type motion. Most piezo tips screw directly into the handpiece with the use of a special wrench. In order to create a smooth scaling sensation, piezo tips require precise adaptation of the lateral tip surface to the tooth. Since piezo tips are screwed into a fixed position, they can not be rotated in the handpiece. Clinicians wishing to use the lateral surface will need to reposition the tip more frequently on the tooth surface to keep this specific surface on the tooth.

Magnetostrictive units create vibrations in either a 25,000 or 30,000 cycles per second (CPS) range. Tip vibrations for piezoelectric units range from 25,000 to 50,000 CPS. Each type of unit produces ultrasonic vibrations. In direct contrast, sonic scalers, classified as power scalers, attach to air hoses. Sonic scalers operate at 2,500 to 8,000 CPS, and do not create ultrasonic vibrations.

Cavitation results as the water flows over a rapidly moving ultrasonics tip, creating small bubbles that implode releasing a burst of energy that further enhances the disruption of hard and soft deposits. Cavitation occurs at the activated tip end of both magnetostrictive and piezoelectric inserts; however, the movement of the sonic scaler tip is not sufficient to create this phenomenon.

Fluid flows through either a small hole in the tip, at the base of the tip or through a small water conduit positioned so fluid flows directly on to the back of a tip. This fluid cools and lubricates the tip and continuously washes the field creating greater visibility.

In order to achieve effective debridement the activated tip must scale all tooth surfaces. Use short, overlapping strokes. Keep the tip moving and spend time getting familiar with the anatomy of each tooth. Some clinicians think ultrasonic scaling is a magic bullet and deposits will just disappear with one quick pass through the pocket. Unfortunately, this approach can burnish existing calculus and lead to missed deposits. Take enough time to let ultrasonic technology really work.

Tenacious deposits are easier to dislodge if one uses a tapping motion with the side of the insert on the edge of the deposit. Be patient. It can take more time than you might expect to remove a stubborn piece of calculus.

Observe what comes off the tooth or out of the pocket. Cloudy irrigant or chunks of deposit are indications that deposits are being removed. Clear fluid can indicate complete deposit removal but roughness on the root surface need evaluation. Some teeth that have anatomical abnormalities and others have rough surfaces. This is different from residual calculus.

From robust to diamonds

There are many inserts on the market today. Your clinical effectiveness and your patient’s comfort depend on knowing what insert tip to use and when and how to use the tip correctly.

Fifty years ago, all ultrasonic insert tips were large and robust, capable of disrupting heavy stain and tenacious calculus deposits. These inserts - and their variations - are still available today. Use robust inserts for gross deposit removal only. Some common examples of these tips are each manufacturer’s version of a universal 10, a triple bend, beaver tail, or a power tip.

The sheer bulk of robust insert tips reduces tactile sensitivity, creates significant vibration, and is more likely to create patient discomfort. In addition, the diameter creates soft tissue distention, which many patients find uncomfortable. One should take care when scaling delicate root surfaces with these powerful tips. Robust inserts really shine when removing industrial strength deposits that will not budge with the newer, slimmer tips.

While it is quite important to have these robust inserts available, they are not the insert of choice for routine biofilm and deposit removal. Select a universal slim tip for routine maintenance appointments. Operate the tip at the lowest power setting in the low to medium range that allows deposit removal. If a slim tip cannot remove a tenacious deposit, try a more powerful tip surface, use different tip configuration or select a more robust tip,

Today’s hygienists routinely use universal tips; however, universal tips cannot reach all tooth surfaces effectively. Right and left tips are the perfect choice for challenging clinical situations such as those found around orthodontic appliances, tilted teeth or crowded dentition, bulbous teeth, periodontal splinting and the ultimate challenge - furcations.

Many of today’s inserts have unique clinical applications so it is a shame to rely totally on slim universal tips. From an ergonomic standpoint, right and left inserts can save your hands and wrists from unnecessary stress. For example, the little curve in the tip is perfect for scaling lower anterior teeth that have a lingual tilt or significant overlapping.

In addition to tip configurations, there are also specialty tips designed for use around implants and delicate cosmetic restorations. Piezo electric technology is the leader in ultrasonic implant tips. One company makes an insert made out of carbon composite designed for use in several different machines. Another unit-specific piezo tip is plastic-coated. One manufacturer makes a screw-on plastic slim universal magnetostrictive insert tip.

Diamond-coated tips are the most recent innovation in ultrasonic scaling tips. These inserts, designed to remove tough deposits such as burnished calculus, pack a punch that most clinicians are not prepared to handle. The grit of the diamond coating can vary widely. Diamond-coated inserts have the potential to destroy tooth structure much faster than our traditional all metal tips. One manufacturer has a disclaimer stating that diamond tips are for surgical use only, which is out of the realm of the dental hygiene practice act.

There are now ultra-thin magnetostrictive and piezoelectric tips that are the diameter of a probe and even an explorer. These unique tips, specifically designed for use in compatible machines, allow clinicians to instrument areas that can’t be accessed by conventional inserts. Microultrasonic scaling is the term used to describe scaling with these new inserts.

Often clinicians are dumfounded to find they are removing deposits with an ultrasonic scaler that was not be removed with a hand instrument. Today’s microultrasonic scaling is not a faster methodology but it does allow one to use ultrasonic scalers more precisely in areas that traditional insert tips could not negotiate. Clinicians that have transitioned to using power scalers more are achieving better clinical results than those found with hand instrumentation alone.

The real success or failure in microultrasonic scaling is dependant on many factors. It requires a thorough knowledge of tooth morphology, ability to select the right insert, a quality ultrasonic scaler, scheduling adequate time, a thorough understanding of how to operate a unit that is in good working order, an in-depth understanding of ultrasonic technology and skilled ultrasonic scaling techniques.

Contemporary ultrasonic scaling can help us extend our careers, save more teeth, and lay a foundation for our new clinical comfort zone. Microultrasonics is not a quickie methodology but rather a precise way to deal with the archenemy, plaque biofilm.

The comfort zone of ultrasonic scaling

All ultrasonic units have power/amplitude settings. Higher power levels result in faster deposit removal but remember that higher power levels have a greater potential to create patient discomfort. High power settings are also contraindicated around today’s cosmetic restorations. Some clinicians experience hand and arm discomfort after prolonged usage of robust tips at high power ranges due to increased vibration transmitted to the clinician’s hand, wrist, and arm.

All scaling, regardless of the tip design, will be more effective using a very light grasp and the lightest possible pressure on the tooth surface. Applying excessive pressure with the activated tip dampens tip vibrations resulting in less effective deposit removal. A light touch also improves tactile sensitivity and reduces hand fatigue.

It is important to activate the insert before placing it on the tooth surface. Remember to keep the insert tip parallel with the long axis of the tooth, with minimal pressure. To increase patient comfort, improve tactile sensitivity and reduce spray use the lowest power level that produces effective deposit removal.