Using Komet® guide-pin diamonds for controlled, tissue-preserving crown preparations

Developed to enhance the periodontal health of restored teeth by creating non-traumatic crown margins, Komet® guide-pin diamonds produce controlled, homogeneous shoulder preparations with defined, uniform cutting depths.

The uncoated pin at the tip of each instrument positions and guides the instrument, permitting non-traumatic, tissue friendly placement of crown margins during crown preparation procedures. In subgingival preparations, the guide pin also serves to maintain a predefined distance to the periodontium, avoiding damage to the biological width.

The diamonds’ non-cutting tip is narrower than the width of the diamond-covered portion of the instrument; the tip extends past the end of the diamond surface and assists in retracting the soft tissue to decrease gingival abrasion during preparation. As the instrument is used to prepare the axial and proximal walls, the guide pin limits the depth of cut, facilitates uniform tooth reduction to a depth ideally suited to the crown material, and effectively prevents over-preparation in areas that are difficult to visualize. Komet® Pin Diamonds are offered in a selection of configurations, lengths, and sizes to accommodate specific crown-preparation needs and cutting depths.

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Clinical sequence

Figure 1. Use a tapered S-Diamond (S6878K.314.016) to create occlusal orientation grooves.

Figure 2. Using the same instrument, make buccal and palatal orientation grooves, and then prepare the tooth on facial and palatal sides from the supragingival level up to the proximal surface. Follow up with a size 012 S-Diamond (S6878K.314.012) for initial proximal separation and preparation to the level of the gingival margin.

Figure 3. Using a guide-pin diamond selected for a relatively pronounced chamfer (856P.314.021), create facial and intrasulcular preparations. When the cutting depth reaches the desired level, finish the facial surface with the Komet® 8856P.314.021 guide-pin diamond.

Figure 4. If necessary for all-ceramic crowns and veneers, increase the cutting depth with a matching non-pin diamond (8856.314.018).

Figure 5. Complete palatal and intrasulcular preparation with the pin diamond (878KP.314.021), followed by the 8878KP.314.021 for a slight chamfer.

Figure 6. The approximal preparation can be completed with a Komet® sonic tip (SF8878KD).

Figure 7. This SEM micrograph illustrates the guide pin in the vertical position. During the preparation of the subgingival margin, the 0.5-mm-long guide pin assures the pre-defined distance to the periodontium is maintained. Damage to the biological width is effectively avoided.

Figure 8. This illustration displays the guide pin in the horizontal position. For circular reduction, the guide pin guarantees a controlled, uniform preparation with an even cutting depth, creating a defined margin and avoiding the “gutter” effect.

For more information on Komet® guide-pin diamonds, contact Komet USA LLC at (888) 566-3887 or visit www.kometusa.com.