The Blended Approach to Instrumentation

Dental professionals are embracing this technique — which blends the use of ultrasonic and hand instrumentation for improved clinical results — and sales reps are wise to learn what it entails.

Oral health professionals can achieve successful treatment outcomes in nonsurgical periodontal therapy through the combined use of hand and power instrumentation, or the blended approach. And dental sales reps stand to benefit from a basic under­standing of this technique and what it entails from a dealer standpoint.

RESEARCH HAS SHOWN THAT THOROUGH COVERAGE USING ULTRASONIC INSTRUMENTATION REQUIRES NO LESS TIME INVESTMENT THAN HAND INSTRUMENTATION.Newly engineered designs in both hand and power instrumentation make them more valuable and effective than ever. Modern dental professionals have the advantage of providing optimal periodontal patient care through the blended approach to increase clinical success, improve outcomes, and, ultimately, help patients achieve good oral and overall health.

The dental endoscope and dental videoscope, with their subgingival vision, have shown that even after hand and power instrumentation, calculus goes undetected by the explorer and is therefore overlooked.1,2 Research in biofilm, enhanced by the dental endoscope, has established a new paradigm for periodontal therapy, revealing a need for more meticulous and thorough debridement. Studies demonstrate that the presence of inflammation after nonsurgical periodontal therapy usually reveals residual deposits.3,4 Depending on the host response to inflammation, disease will often continue to progress in unresolved areas. In order to reduce chronic gingival inflammation following nonsurgical periodontal treatment, instrumentation must include complete biofilm and calculus removal.5 This is achieved through therapeutic periodontal scaling and root planing (SRP) — which is regarded as the gold standard in the nonsurgical treatment of periodontitis.6–8 But oral health professionals must determine how to accomplish this: via ultrasonics, hand instrumentation, or a combination of the two known as the blended approach?

Ultrasonic Technology

Ultrasonic scalers, when used effectively, can provide many benefits to clinicians and their patients. Dental sales reps should know that ultrasonic units are available in magnetostrictive or piezoelectric technology. Power instrumentation excels in the removal of biofilm and heavy ledges of supra- and subgingival calculus, leading to decreased bacterial counts and improved tissue health. In order for oral health professionals to achieve the best clinical outcomes when using ultrasonic instrumentation, they must meticulously instrument the complete root surface.9,10 In areas where the ultrasonic insert/tip (UIT) does not touch or strokes are insufficient, the root surface could still harbor embedded calculus and biofilm.9 Some clinicians hold to the misconception that an ultrasonic device used on low power and waved around inside the pocket will deplaque the root surface. While the lavage provides some benefits, it does not dislodge all layers of the biofilm unless the UIT covers every square millimeter of root surface.11 Although ultrasonic instrumentation may seem effortless, its effectiveness depends heavily on proper technique and sufficient time investment. Improper grasp, power level, pressure, adaptation, speed, and stroke can alter the efficacy of the instrument and possibly damage the tooth structure.12 Proper activation and adaptation are fundamental to success. Unlike hand instruments, which are used from an apical to coronal direction, ultrasonic instrumentation is accomplished from the crown to the apex. Effective power scaling requires adapting the terminal 2 mm to 3 mm portion of the UIT to the root surface and using continuous, overlapping strokes at a moderate to slow pace. Using methodical patterns activated in strokes across each surface will assist in attaining complete root coverage.13

For thorough debridement, clinicians must spend an adequate amount of time and use a variety of UITs. Research has shown that thorough coverage using ultrasonic instrumentation requires no less time investment than hand instrumentation.14 A combination of horizontal and vertical UIT orientations will provide the best periodontal debridement. The dental endoscope reveals that thorough removal of deposits requires repeated strokes over the same surface because calculus is removed layer by layer.10 If calculus or biofilm persists after therapy, the biofilm recolonizes quickly, within hours, causing inflammation.15,16

During the 1990s, power scaling became an accepted modality for SRP due to innovations in the shape and diameter of UITs. Advances in the technology behind thin and ultra-thin UIT design changed the clinician’s approach to providing SRP and periodontal maintenance. Today, wide assortments of UITs are available.17


Ultrasonic inserts/tips (UITs) are designed for specific purposes and accessibility; therefore, clinical selection is based on UIT geometry, type, and location of calculus, as well as patient health status and root anatomy.
Cylindrical in cross section: The shape of the majority of UITs; most effective for biofilm removal.
Angular shapes/edges: Ideal for tenacious calculus and stain.
Square with beveled edges and triple bends: Most recent design additions that enhance removal of heavy stain and calculus.
Triangular/square/diamond in cross section: Said to be the most efficient at removing heavy stain and hard deposits, due to a surge of energy wave along the edge.
Ultra-thin and beveled edge: Can be used on high power; when not used at adequate power, have the potential to polish over the outer surface of mineralized deposits.

Hand Instrumentation

Hand instruments can be divided into two categories: assessment and treatment.18 Instruments for data collection and tissue assessment include a variety of explorers and probes and are indispensable to the diagnosis and classification of periodontal diseases. Effective treatment requires proper assessment of the contours of the tooth and quantity, quality, and location of calculus, pocket depth, soft tissue, and bone levels. Because subgingival calculus usually forms in rings around the root or in ledges, vertical or oblique exploring strokes with light pressure are best for assessing calculus and cementum through the corresponding vibrational bumps, jumps, and clicks.

Treatment instruments include a wide variety of scalers, such as sickles and curets. Sickles have a cross-sectional shape of a triangle and can be curved or straight. Curets have a cross section of a half-circle, and can be universal or area-specific. The cross section and the internal angulation are important considerations in instrument selection. Other scaling instruments include chisels, files, diamond-coated files, and hoes. For example, Hirschfeld files can be used to break up sheets of residual or burnished calculus especially when applying vertical or oblique strokes. The file has multiple small cutting edges that initially fracture the surface of and then break up burnished calculus that is difficult to remove with other types of bladed instruments.19 Understanding specific instrument designs will assist dental sales reps when speaking with their customers.

Many improvements have been made in instrument design. Advances include extended and angled terminal shanks for better access, while others offer shanks with varying degrees of flexibility and rigidity to aid in the debridement of heavy calculus, as well as biofilm removal. Some instruments have unpaired working ends — such as a thin, short sickle for use on lower anterior teeth paired with a rounded disc or hoe, which is useful for extrinsic stain removal. New sickle scalers and area-specific curets feature thin working ends with short, curved blades. Unpaired sickle and curet combinations are also available.18,20

Instrument handles come in a variety of diameters, shapes, padding, weights, and materials. Using hand instruments with different diameter handles can reduce hand stress and repetitive motion injuries. Research suggests that the optimal handle diameter should be at least 10 mm and the optimal weight should be 15 g or less.21 Clinician comfort is the primary consideration. Instruments manufactured with a textured grip surface or surfaces made with materials that increase friction between gloved fingers and the instrument decrease pinch forces.22 Instrument handles come in resin or stainless steel with choices of etched design patterns to prevent slipping and ensure a secure grasp.

Area-specific (Gracey) curets are available in regular, extended shank, extended shank mini, and micro minis. Extended shanks provide an additional 3 mm in the shank for deep pockets of 5 mm or greater, along with 10% thinner blades for easier insertion. Mini-bladed instruments feature blades that are 10% thinner and 50% shorter than a regular Gracey blade. Rigid mini-bladed Gracey curets with hard, sharp blades are available to aid in scaling tenacious or burnished calculus and do not flex when applying lateral pressure. Mini-bladed Gracey curets provide access to difficult-to-reach areas during nonsurgical periodontal therapy. The small blade enhances subgingival access and helps to prevent unintentional trauma to the epithelial attachment.

When scaling in furcations, narrow pockets, line angles and buccal or lingual root surfaces, the miniature blades of mini curets provide improved adaptation and tactile sensitivity. For this reason, they are used during SRP following either ultrasonic or traditional hand scaling. Micro-mini Gracey curets feature blades 50% shorter than standard Graceys, but extra-thin with a 20% thinner blade than the minis. This decrease in bulk allows the micro-mini Gracey curets even greater access to tight, narrow periodontal pockets and complex furcations, line angles, narrow anterior pockets, and root concavities. The shank design is similar to the rigid shank of traditional Gracey curets and is beneficial in removing burnished, tenacious deposits. Basic principles include ensuring the blade extends apically to the calculus deposit in a deep pocket and placing the terminal shank parallel to the surface being instrumented.

A new area-specific curet, honed at a 60° angle rather than the traditional 70° Gracey angle, has been developed for periodontal maintenance but can be applied to other applications. These new instruments have shorter, thinner blades than the standard Graceys and are longer than the mini Gracey curet. They also feature a modified rigid shank 2 mm longer than the standard Gracey. These instruments are designed to provide easy access and insertion under tight tissue in areas with attachment loss. Periodontal maintenance curets may be used to remove biofilm or soft calculus on teeth with tight tissue, recession, or residual pocket depths.

Improved formulations of stainless or carbon steel alloys enable the blades of hand instruments to stay sharp longer. The use of sharp curets is necessary for sensory vibrations to be effectively transmitted from the shank to the finger tips. Clinical advantages of working with sharp instruments also include more efficient working time, less fatigue on the patient and clinician, less discomfort for the patient, reduced pressure or force on the fulcrum and decreased risk of burnishing deposits.


  • The dental endoscope and dental videoscope have shown that even after hand and power instrumentation, calculus goes undetected by the explorer and is therefore overlooked.
  • Research in biofilm, enhanced by the dental endoscope, has established a new paradigm for periodontal therapy, revealing a need for more meticulous and thorough debridement.
  • Ultrasonic units are available in magnetostrictive or piezoelectric technology; they excel in the removal of biofilm and heavy ledges of supra- and subgingival calculus, leading to decreased bacterial counts and improved tissue health.
  • Although ultrasonic instrumentation may seem effortless, its effectiveness depends heavily on proper technique and sufficient time investment; furthermore, research has shown that thorough coverage using ultrasonic instrumentation requires no less time investment than hand instrumentation.14
  • Ultrasonic instrumentation disrupts biofilm and flushes out bacteria, but acoustic microstreaming — the flow of water that occurs around the tip of the instrument — does not kill bacteria and periodontal pathogens. Ultrasonic instrumentation adequately applied will not completely eliminate bacteria and pathogens but will reduce their numbers.34
  • Hand instruments can be divided into two categories: assessment and treatment.18 Instruments for data collection and tissue assessment include a variety of explorers and probes and are indispensable to the diagnosis and classification of periodontal diseases.
  • Treatment instruments include a wide variety of scalers, such as sickles and curets.

The Blended Approach

The blended approach to instrumentation uses both hand and ultrasonic instruments for effective SRP and debridement procedures during periodontal maintenance.23,24 Biofilm and calculus removal remains the fundamental approach for the resolution of inflammatory periodontal diseases and can be best accomplished with the blended approach. Both types of instrumentation offer unique benefits and both have strengths and weaknesses. Clinicians will need to decide which approach is best, as some patients cannot tolerate the temperature or volume of water produced during ultrasonic scaling and others may have metal sensitivities that preclude the use of hand instruments.

The combined use of both modalities enables each method’s strengths to be used.25,26 For example, not all hand instruments easily access the base of deep, narrow pockets. On the other hand, the appropriate UIT can reach the base of deep, narrow pockets more easily. For both hand and power scaling, the correct techniques and appropriate instrument selections to maneuver anatomical concavities and convexities drive optimal patient outcomes.27–29

Both methods require correct patient-operator seating positions. Moving on the stool from the front, side, and back positions of the patient promotes neutral body posture. Alternative seating positions and fulcrums, as well as the correct use of the dental light also provide improved ergonomics. Lighted loupes and double-sided mirrors can enhance operator visual guidance. When choosing hand instruments, clinicians should consider the overall handle size, shape, weight, and maneuverability of the particular instrument in order to reduce force exertion while maintaining neutral wrist positioning. Some ultrasonic UITs and hand pieces offer a swivel feature allowing clinicians to change direction of the tip with greater ease and without interruption.30

Clinical Applications

When treating plaque-induced gingivitis, clinicians may begin with ultrasonic or hand instrumentation.31 Standard-sized UITs work best when used on heavy deposits, while thin to ultra-thin UITs work better on moderate to light deposits. After power instrumentation is complete, a hand scaler can effectively remove residual calculus or stain. New choices for stain removal include hand instruments paired with sickles and discs. Additionally, there are many choices for posterior interproximal scaling such as the 204 series or a jacquette. Clinicians should then evaluate the tooth surfaces with an 11/12 explorer, followed by polishing and fluoride application, if indicated.17

Treating patients with chronic periodontitis first requires assessment for pain management, followed by removal of supragingival deposits using ultrasonics with standard UITs. Subgingival deposits should then be removed with thin UITs and power levels appropriate to the deposit being removed. Ultrasonic instrumentation requires sufficient power to remove the bulk of the deposit.17 Following the use of thin UITs, the root surfaces should be evaluated with an explorer and debridement continued with hand instruments using universal, then area-specific curets to completely cover root contours.27 For example, the Gracey 17/18, counterpart of the Gracey 13/14, was designed with a deep bend on the lower shank for accessing far distal posteriors while clearing crown interference. The 17/18 Gracey enables clinicians to lower the handle so the patient does not have to open as wide and allows the use of an extraoral fulcrum for the maxillary arch to ensure the terminal shank of the instrument is parallel to the long axis of the tooth. The rounded back minimizes tissue trauma and allows easy insertion to the base of the pocket.

The Gracey 15/16 is the contemporary version of the 11/12, a mesial posterior instrument. When the original 1/2, 3/4, 5/6, 7/8, 9/10, 11/12, and 13/14 area-specific curets were introduced in the 1940s, dentistry was exclusively a stand-up profession. The angle of the mouth accessed by dental hygienists changed with the advent of sit-down dentistry. In response, instrument manufacturers modified posterior curets and developed the 15/16 for mesial posterior surfaces and the 17/18 for distal posterior surfaces. Both modifications allow increased instrument access with a low handle for arch clearance. The design of the shank helps clinicians maintain a neutral position of the hand, wrist, and forearm by decreasing wrist flexion.


The anatomy of the periodontal pocket determines which curet to select. Clinicians use extended length curets in deep, wide pockets and mini and micro-mini curets in narrow pockets. Following deposit removal with hand instruments, use UITs on a low setting for final smoothing to remove any smear layer from the root surface. Oral health professionals should avoid over-instrumenting with power and hand scaling and polishing in order to reduce the risk of dentinal hypersensitivity.

Clinicians are educated to continue the instrumentation process until all deposits are removed. Even then, case-specific variables, such as patient discomfort, visibility, time allotment, and skill level impact the final result.17 However, when calculus remains after treatment, biofilm quickly recolonizes on residual deposits, keeping the area inflamed.32 When bleeding on probing is evident at the 4- to 6-week tissue re-evaluation, dental endoscope studies show residual calculus likely remains, thus preventing the pocket from resolving.3,4


New technologies, such as the dental endoscope and dental videoscope, have revealed that a high standard of care is needed to provide acceptable treatment outcomes.33 The best clinical results are achieved when oral health professionals use the blended approach — a combination of hand and ultrasonic instrumentation. Thin and ultra-thin UITs, as well as mini and micro-mini curet blades enable access into concavities and convexities as never before. The blended approach to instrumentation joins the advantages of both techniques, and dental sales reps are wise to stay current on the instruments it utilizes for maximum sales success.

This article is adapted from one previously published in Dimensions of Dental Hygiene, and was made possible through an unrestricted educational grant from Hu-Friedy.


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From MENTOR. January 2018;9(1): 30-33.

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