QUESTION: I was taught to grasp the curet with a relaxed, curved index finger, but this position makes it difficult to scale with much force. Which type of grasp do you recommend for the scaling of tenacious calculus?
ANSWER: The relaxed modified pen grasp that you describe is better suited for procedures that do not require much force, such as probing and exploring, or for light deplaquing strokes with a thin ultrasonic insert/tip (Figure 1). In the relaxed modified pen grasp, the fingers and thumb are curved, creating light pressured strokes whether pivoting or using slight finger-flexing motions. This relaxed grasp is not appropriate for scaling because it results in a weaker, inadequate stroke and leads to finger flexing, which is not recommended for heavy calculus removal. A firm modified pen grasp—where the terminal joint of the index finger is straight—is necessary to generate strokes with enough force to remove calculus (Figure 2).
In the firm modified pen grasp, the fingers and thumb should remain more rigid with the index finger bent at the first joint (next to the knuckle) and drawn back on the handle of the instrument. This creates a tripod-like position. The middle finger should be slightly bent at the first joint (next to the knuckle) so that it is shorter than the ring finger. The instrument should then rest on the bony side of the middle finger, next to the fingernail. This provides the firmest fulcrum point for the best control, leverage, and lateral pressure.
Thumb position is integral to achieving sufficient lateral pressure. The middle of the thumb pad should be placed on the instrument handle to achieve optimal pressure and control. In order to get firm lateral pressure with the thumb, the thumbnail should line up with the blade of the instrument and the surface being scaled. Whenever possible, the thumb should be positioned to push directly onto the surface being instrumented. When scaling from one surface to another around a line angle, many clinicians don’t change their thumb position accordingly—reducing the efficacy of their strokes.
Sometimes, another finger in the grasp provides the lateral pressure instead of the thumb. For instance, when using an intraoral rest with a Gracey 11/12 on the mesial surfaces of the mandibular molar teeth, the side of the middle finger leaning into the tooth provides lateral pressure—not the thumb.
The success of the firm modified pen grasp is based on several factors. In posterior areas, it lifts the handle to a higher position, which provides proper working angulation. If you grasp the instrument with the soft pad of the middle finger, the handle tends to drop too low and the blade angulation is too closed. In contrast, the side of the middle finger provides firm resistance in the fulcrum. By getting the bony part of the finger underneath the instrument, a strong pivot point for the stroke is achieved. When the instrument slips down onto the soft fleshy part of the finger, there is nothing firm for the instrument to lean against, so the pressure required for a strong, effective stroke is lost.
Many dental hygienists are only taught the relaxed modified pen grasp, but both the relaxed and firm grasps should be used depending on the type of procedure being performed and the amount of pressure required to complete it. Instrument grasp should be continuously adjusted throughout the procedure to ensure efficacy and the safety of both clinician and patient.
From Dimensions of Dental Hygiene. October 2011; 9(10): 74.