Diversity in Manual and Ultrasonic Instrumentation

Whatever the reason, using outdated tools increases the potential for an uncomfortable patient experience and uncontrolled disease, while at the same time subjecting DHCPs to increased risk for musculoskeletal disorders. The goal of periodontal therapy is repair and regeneration. In order to achieve both these goals while delivering evidence-based care, it is essential for DHCPs to have a solid understanding of newer ultrasonic and hand instrument designs, along with their variables and features.

Ultrasonic scalers were first introduced to dentistry in the 1950s to remove supragingival calculus. By the 1980s, as tip designs improved, a paradigm shift in treatment occurred, and research began to support the use of ultrasonic instrumentation over hand instrumentation. In a study comparing debridement results, Mittal and colleagues¹ found that instrumentation with a curette produced a rougher root surface and caused more root surface removal, thus ultrasonic instrumentation proved less damaging. Shortly thereafter, there was also a fundamental shift in understanding the cause and treatment of periodontal disease. Scaling and root planing with sharp instruments to remove calculus and cementum was no longer considered necessary to achieve root cleanliness.² Rather, the focus shifted from calculus to the removal of oral biofilm and preservation of tooth structure.

As knowledge of the multifactorial nature of periodontal disease continues to increase and technological advancements keep pace with research findings, DHCPs are more aware of the relationship of periodontal therapy options, microbial dynamics, and their relationship to instrumentation selection.³ By incorporating a blended approach using hand and ultrasonic instrumentation when performing non-surgical periodontal therapy (NSPT), DHCPs are able to deliver greater comprehensive care to patients and achieve more successful treatment outcomes.⁴  In order to take full advantage of today's wide variety of hand and ultrasonic instruments, DHCPs should familiarize themselves with terminology and features, along with the unique clinical applications and protocols of each tool in order to optimize capabilities and facilitate delivery of periodontal care.³

Ultrasonic units and tips have evolved significantly over the years. While there are several different magnetostrictive and piezoelectric units on the market, choosing between the two platforms is not a straightforward decision. Guignon⁵ once made the comparison that choosing between magnetostrictive and piezoelectric units is like choosing between a vehicle with a gas or diesel engine. For example, the process for creating power and the action, broken down into four steps, are the same for gasoline-powered and diesel-powered vehicles. However, the execution of these steps is different. With magnetostrictive and piezoelectric units, the process for creating power is different, but the actions, which are also broken down into four steps, are the same. The mechanisms of action of ultrasonic instrumentation are mechanical vibrations, irrigation, cavitation, and acoustic microstreaming. When choosing between magnetostrictive and piezoelectric units, tip design and selection are the greatest variables in successful ultrasonic instrumentation. A variety of tip designs is required when performing a blended-approach NSPT.

One of the key elements of tip design is diameter. Tip diameter determines the amount of pressure exerted by the clinician, cavitation and microstreaming, and accessibility to the treatment site.⁶  Other key tip design features include: tip shape, which influences the degree of contact between tip and tooth surface, along with pressure; tip geometry, which influences angulation and adaptation of the tip to the tooth surface; and tip profile, which determines the number of bends in the shank and influences adaption and deposit removal.⁶

Ultimately, tip selection should be based on deposit type and the area to be treated. As both magnetostrictive and piezoelectric units offer an assortment of tips, determining which tip designs are required can be overwhelming for the DHCP. George and colleagues⁶ recommend that all DHCPs have four basic tip designs in their armamentarium to ensure efficacy and efficiency in removal of various deposits that adapt to specific portions of tooth anatomy: a standard straight tip, a right and left curved tip, and an ultraslim tip.

Like ultrasonic units and tip designs, hand instruments have undergone significant changes, featuring advancements in materials, technology, and design (with all parts of the instrument being modified). These advancements lessen the incidence of injury and development of musculoskeletal disorders for practitioners, increase patient comfort during treatment, account for anatomical differences in dental anatomy, and allow the DHCP to treat advanced periodontal diseases effectively while preserving tooth structure.

Handles are now larger-with wider diameters-and lighter, featuring tapered shanks to lessen muscle strain, help maintain control in a wet environment, and reduce pinch force. Various texture and knurling patterns also help the practitioner maintain control and reduce pinch force. Paradise Dental Technologies (PDT) and American Eagle offer unique texturing and knurling patterns on their resin-based handles. Nordent Manufacturing offers hollow, glare-resistant, stainless-steel handles, while LM-Dental handles are embedded with RFID technology and have a solid metal core covered with a medical grade silicone.

Advancements in metallurgy and cryogenic processing have produced instruments with razor sharp edges that stay sharper longer. Hu-Friedy EverEdge 2.0, Nordent Xdura^™, American Eagle Talon Tough, and LM-Dental's LM-DuraGradeMax are all stainless-steel instruments that require less frequent sharpening. Advancements in metallurgy and cryogenic processing have also produced designs that stay sharp throughout the life of the instrument, such as American Eagle XP and LM-Dental Sharp Diamond^™ instruments.

Dental manufacturers have also improved instrument design by tapering, modifying, and miniaturizing working end and shank design features to facilitate precise placement of the instrument to the tooth surface. These improvements include extending shank length, increasing shank diameter, and reducing the size of some working ends by 50%. Instrument designs have also improved by combining the features of sickle and curette designs to create instruments that can be used in all areas of the mouth, requiring fewer tools to provide treatment.

Incorporating new ultrasonic and hand instruments provides benefits for the DHCP and the patient. To use new designs effectively, practitioners should understand basic instrumentation concepts and principles. Manual and ultrasonic instrumentation is not simply about the procedure. DHCPs must be concerned with factors that impact use, such as the environment, equipment, temperature, visibility, and patient. Improper use of ultrasonic and hand instruments causes damaged cementum, patient discomfort, burnished calculus, tissue trauma, and injury to the patient and the practitioners. Before purchasing advanced tools, DHCPs must have a solid understanding of newer ultrasonic and hand instrument designs and consider their rationale for use. A diverse armamentarium allows the practice to provide patient-specific treatment and ultimately improve outcomes.

Joy D. Void-Holmes, RDH, BSDH, DHSC
Dental Hygiene Program Chair • Fortis College
Landover, Maryland
Adjunct Faculty • American Denturist College
Eugene, Oregon
CEO/Founder •  Dr. Joy RDH
Washington, DC