Mastering the Slim Ultrasonic Tip -
(Part II in a series)
Why to use them. Where to use them. How to use them.

by Jill S. Nield-Gehrig, RDH, MA
Arden, North Carolina

In an earlier article (Parkell Today November - 04) I discussed some of the advances that have been made during the past decade or so in ultrasonics, and how the once-lowly ultrasonic instrument is now appreciated as a major (and according to some, THE major) weapon in the war against periodontal disease.

In this article, I’d like to focus on one of the breakthroughs that was responsible for this change in perception: The slim insert.

Visionaries like Dr. Thomas Holbrook had been custom-grinding their own slim tips for a least a decade before manufacturers began in the late ‘80’s producing inserts thin enough to slide into subgingival pockets.

Those tips, plus the research by Walmsey, which appeared about the same time, really launched the ultrasonic movement of the ‘90’s. Walmsey showed how effectively ultrasonics could disrupt subgingival plaque, even though the tip itself never touched them.

Today slim tips are a mainstay of most hygiene departments. They’re available in straight, left and right designs (fig 1), plus a few specialty designs for specific situations, which I’ll discuss in a future article. Though some dentists and hygienists use only the straight thin tip, you’ll find life a lot easier if you incorporate several thin designs into your practice.

In this article we’ll discuss the different slim-tip designs ... which tooth surfaces they are most appropriate for ... and I’ll offer some suggestions for getting the most out of them.

There are two basic techniques for adapting a slim-diameter instrument to a tooth.

In the oblique technique (or “Curet Position”), the working-end is positioned with the lateral surface in an oblique, almost horizontal, orientation to the long axis of the tooth. The tip is positioned like the working-end of a curet (fig 2,). The face of the working-end should be at a zero degree angulation to the tooth surface.

The oblique technique is effective when removing calculus deposits above or slightly below the gingival margin.

In the vertical technique (or “Probe Position”), the tip is positioned like a calibrated periodontal probe, with the point directed toward the junctional epithelium (fig 3).
The vertical technique is used for calculus removal and deplaquing when instrumenting shallow or deep periodontal pockets.

Instrumentation of anterior sextants

Because the roots of anterior teeth are not highly curved, the straight slim-diameter tip can reach most surfaces. I use the straight slim-diameter tip for anterior debridement, even in deep periodontal pockets.

For calculus removal above and slightly below the gingival margin, I use the oblique technique. As you can see in figure 4, I position the slim tip at an angle to the long axis of a maxillary central incisor. I insert the working-end slightly beneath the gingival margin. I’m leading with the convex back of the working-end toward the gingival margin.

Traditional finger rests often aren’t appropriate for ultrasonic instrumentation. Think about it. With a curet, you’re applying manual force, so the rest serves as a fulcrum. The closer the rest is to the tooth being instrumented, the greater your mechanical advantage. With ultrasonics, however, the oscillating tip is doing the hard work, and the finger rest merely provides stability. (If the metaphor for a curet is a crowbar, the metaphor for an ultrasonic tip is a violin bow.)

Like a violin bow, you want to be able to easily adjust the tip orientation to conform to the curved tooth surface. If you use a posterior rest when instrumenting the lingual, you’ll have all the stability you need, and your fingers won’t get in the way (figs 5 & 6).

To instrument the facial root surface I switch to the vertical technique and use the straight tip almost like a periodontal probe. When I’m using a magnetostrictive tip, I apply either the side of the tip (fig 7) or the back (fig 8). When I’m using a piezo tip, I use only the side, as the back may cause excessive hammering and sensitivity.

Instrumentation of posterior sextants

A straight slim tip can certainly be used in the posterior. But because of the root curvature, its usefulness is limited to surfaces within 4mm of the CEJ. When using a straight tip, I generally employ the vertical technique, starting at the CEJ and working toward the base of the pocket (fig 9). As with all debriding, I try to touch every point on the root surface - as if I were shading it with an artist’s charcoal pencil.

When there’s significant recession or periodontal pocketing, I switch to a curved tip that conforms to curved root surfaces. Many operators avoid these tips, because they’ve heard that they require repeatedly switching tips. In fact, once you get with the system, you insert each tip just once.

But first: How to tell your “left” from your “right”

Curved Slim Tips are identified as “Right” or “Left”. This can be extremely confusing to the new user.

To identify which tip you’re holding, rotate the insert so the point is facing away and look at the tip from the back. The direction of the bend in the tip will identify the tip as right or left. The terms “right and left” refer only to the bend in the design, not to a location for use in the mouth (fig 10).

How to minimize the number of switches during posterior instrumentation.

Both the right and left slim-diameter tips are needed to instrument the entire posterior dentition. The secret to doing this efficiently is to instrument all surfaces in both arches that are reachable with one curved tip ... then switch inserts ... and instrument all the surfaces reachable with the other.

For example, I begin with the right tip in the oblique position to remove deposits above and slightly below the gingival margin. Using the same tip, I switch to the vertical position for subgingival debridement.

Rather than describe which insert and which technique I use for the various surfaces, I’ve drawn you a picture (figs 11, 12, 13, 14).



Remember, the idea is to complete all instrumentation using one curved tip before you switch to the other.

A few suggestions for using slim-diameter curved tips

The best adaptation to the lingual aspect of the mandibular and maxillary posterior teeth is achieved by using the vertical technique to adapt the back of the working-end to the surface being treated (fig 15). However, this can be difficult-to-impossible when using a standard fulcrum. For lingual instrumentation, a cross-arch fulcrum works best (fig 16.) Since I’m right handed, I use a right tip and vertical technique to instrument the linguals of the left-mandibular and right-maxillary posterior sextants.

To instrument the proximal surfaces of the right-mandibular sextant, I use the right-curve inserts and an oblique technique (fig 17). This allows easy access to proximal surfaces. If I discover interproximal accretions, I use tapping, horizontal strokes with minimal pressure to dislodge it.

In this article, we’ve discussed the sometimes-confusing topic of slim inserts and shown how each shape (straight, right-curve, and left-curve) has a place in instrumentation. In the next article, we’ll discuss some specialty thin inserts, and show how to ultrasonically instrument a furcation as well as remove an amalgam-overhang.

Soft-tissue periodontal models are recommended by the author both for study and practice. All soft-tissue models in this article were supplied courtesy of Kilgore International http://www.kilgoreinternational.com 1-800-892-9999)

About the Author:

Former Dean of Allied Health and Public Service Education at Asheville-Buncombe Technical Community College, Jill S. Nield-Gehrig, RDH, MS, has been a dental hygienist for 31 years and an active educator for 25 of those years. She received her RDH from Temple University, her BS from Millersville University and a Masters Degree from St. Mary’s University.

A sought-after lecturer and consultant, Jill recently co-authored Foundations of Periodontics for the Dental Hygienist and was the sole author of Fundamentals of Periodontal Instrumentation & Advanced Root Instrumentation - 5th Edition (both published by Lippincott Williams and Wilkins.)

She can be reached at jng_consulting@bellsouth.net.


Recent books by Jill S. Nield-Gehrig, RDH. MS

Foundations of Periodontics for the Dental Hygienist edited by Jill S. Nield-Gehrig, RDH, MA and Periodontist Donald E. Willmann, DDS, MS is a heavily illustrated, easy-to-understand text that uses an evidence-based approach to show how the latest research (biofilms, host responses to pathogens, etc.) is influencing hygiene therapy. According to Dr. Larry Burnett, Foundations is destined to become “a standard for dental hygiene programs everywhere.” $51.95 423 pages http://connection.lww.com/go/nieldfoundations

Fundamentals of Periodontal Instrumentation & Advanced Root Instrumentation by Jill S. Nield-Gehrig, RDH, MA is a lavishly illustrated “cookbook” for the dental hygienist as well as the GP or periodontist who personally performs hand- or power instrumentation. The rationale for each procedure is clearly explained, as are the proper technique and contraindications. $57.95 640 pages http://www.lww.com/eproduct/0,0,72924,00.html

Both books are available from Lippincott Williams & Wilkins (www.lww.com or 1-800-638-3030), Amazon.com, or from your local health sciences bookstore

 

 



Figure 1: Though some dentists and hygienists use just the straight thin tip - adding the left- and right-curve to the armamentarium makes it a lot easier to do a good job.

Figure 2: Oblique Technique - The tip is placed at roughly a 90-degree angle to the axis of the tooth. Think “curet.” Here I’m debriding a proximal surface. In figure 4 a facial surface


Figure 3: Vertical Technique - The tip is directed down the axis of the tooth. Think “perio probe.” Sometimes you’re using the side of the tip (shown here and in fig 7) sometimes the back (fig 8).


Figure 4: In the anterior, the oblique technique works best for calculus above or slightly below the gingival margin.

NOT THIS (Figure 5) Note that the traditional intraoral finger rest makes it difficult to adapt the lateral surface of the tip to the lingual surface of a mandibular anterior tooth.


THIS! (Figure 6) Rotate the instrument handpiece to the side of the mouth and establish a finger rest several teeth away. A finger rest on the posterior teeth makes it easier to correctly adapt the lateral surface tip to the lingual surface of a mandibular anterior tooth.




Figures 7&8: When using a magnetostrictive scaler you can debride with either the side of the tip (fig 7) or back (fig 8.) When using a piezo - avoid using the back of tip.



Figure 9: Because bicuspids and molars have curved roots, straight tips are generally used in the posterior only within 4mm of the CEJ. Deeper than that, you need a curved tip.

Figure 10: As you look down the shaft with the tips pointed away from you, the “Left-curve” bends to the left and the “Right-curve” bends to the right. (Because it curves in 3-dimensions, it’s hard to get a really good photograph of a curved slim tip.)


Figure 15: When used vertically, curved slim tips conform nicely to the curved posterior roots.


Figure 16: For posterior lingual surfaces, use a cross-arch fulcrum.


Figure 17: Switch to the oblique technique for posterior proximal surfaces.