January 2011, Volume 7, Issue 1
Published by AEGIS Communications
Convenient, Accurate Retraction Cord Dispensing
Improved yarns and efficient cutting enables proper cord-management technique for impressioning and cementation.
Howard E. Strassler, DMD
One of the most challenging aspects of restorative procedures is the management of the gingival tissues when placing a restorative material. Most restorative materials work best in a dry and uncontaminated field. For fixed prosthodontic treatment, gingival tissue management is critical at two points: making an impression and during cementation-especially with resin-based cements.
When making impressions, tissue management includes displacing the gingival tissues away from the preparation margins so that they can be visualized and impressed while also providing for hemostasis.1,2 Whether one uses conventional impression materials or digital impressioning, it is critical to have the ability to reproduce the critical aspects of the tooth preparation in the impression. An inaccurate impression will lead to a clinically unacceptable restoration.
Gingival retraction and soft-tissue management is also important for clinical situations when, during placement of the restoration, the margins of the preparation are either at or below the free margin of the gingival tissues. The restorative material is at risk of contamination from seepage (blood or sulcular fluid) when attempting restoration placement. This can happen with directly placed adhesive restorative materials or during adhesive cementation of crowns, inlays, onlays, or veneers. Placement of a dental dam is not possible, or its placement may cause gingival bleeding, and the only solution is the placement of gingival retraction cord to control the field and eliminate or minimize contamination of the restorative material during placement. This is especially true when placing composite resin restorations.
While there are a number of clinical techniques for managing gingival tissues in restorative dentistry, the most predictable and popular technique is the use of gingival retraction cord to mechanically displace the gingival tissues without tissue damage in both prosthodontic and operative procedures. Over the years, there have been significant problems with gingival retraction cord that have not been addressed. First, the cord is usually dispensed by pulling the cord from a bottle using a cotton pliers and cutting with a scissors. This technique runs the risk of contaminating the retraction cord. Second, there are no measuring tools as part of the dispensing system, so it is not uncommon to dispense too short or too long a cord for the clinical indication. Most clinicians err by dispensing too long a section of cord that is more difficult to manage when placing it into the gingival sulcus. Also, cord diameter, astringent/hemostatic agent, and cord type have a direct effect on the physical properties of the cord.3
Recently, there has been a significant upgrade in braided cords, which incorporate some of the positive characteristics previously only seen in knitted retraction cords. GingiBRAID+ (DUX Dental, http://www.duxdental.com) is a unique improvement over conventional braided cords. The weave and cotton yarn of the GingiBRAID+ was changed so that the cord has less "memory" and is more easily and precisely placed into the gingival sulcus without causing gingival bleeding and soft-tissue damage. The improved cotton yarn allows for the braided cord to be significantly more absorbent and not split or tear during placement. This superior absorbency contributes to increased absorption of gingival fluids in the sulcus, as well as a swelling effect in the sulcus that contributes to improved retraction for better visualization of margins when making an impression (Figure 1 ). Also, with a braided cord, the clinician has the choice of using either a smooth or serrated cord-packing instrument without fear of tearing or pulling the cord from the sulcus, which can cause additional bleeding and contamination (Figure 2 ).
Clinicians have expressed an interest in more accurate and convenient dispensing of gingival retraction cord. ShortCut from Dux Dental combines convenience, efficiency, and effectiveness in cord dispensing and cutting. It is an all-in-one delivery system for GingiBRAID+ gingival retraction cord. To dispense the braided cord, the clinician merely turns the click-stop dial of the ShortCut device the number of clicks specific to the size desired (Figure 3 ). Typically, three to four clicks provides a length of braided cord for an anterior tooth and four to five clicks provides for a posterior tooth. For large molars, five clicks dispense the appropriate length. Once dispensed, one pushes in on the built-in cutter, dispensing to the needed length for the clinical procedure (Figure 4 ). The ShortCut device is both durable and easily disinfected.
ShortCut is available in braided cord diameters sizes 0, 1, and 2. It is provided as non-impregnated, allowing for the clinician's choice of favorite astringent/hemostatic agent; impregnated with 8% racemic epinephrine and 7% aluminum potassium sulfate; or impregnated with 10% aluminum potassium sulfate (Figure 5 ). The impregnated braided cords can be treated with an astringent/hemostatic agent.
GingiBRAID+ gingival retraction cord and ShortCut's unique blend of technology offers accurate fingertip dispensing and cutting a braided cord. This is also combined with improvements in the cotton yarn used to create the braid so that there is increased fluid absorbency, less "memory" during cord placement, fast-acting hemostasis with proven hemostasis agents, and ease of cord placement without fear of penetrating the cord during gingival displacement or pulling the cord out when removing the instrument.
1. Rosenstiel SF. Issue management and impression making. In: Rosenstiel, SF, Land MF, Fujimoto J, eds. Contemporary Fixed Prosthodontics. 4th ed. St. Louis, MO: Mosby Publishing Inc.: 2006:431-465.
2. Morgano SM, Malone WF, Gregoire SE, et al. Tissue management with dental impression materials. Am J Dent. 1989;2(5):279-284.
3. Del Rocio Nieto-Martinez M, Maupome G, et al. Effects of diameter, chemical impregnation and hydration on the tensile strength of gingival retraction cord. J Oral Rehabil. 2001;28(12):1094-1100.
About the Author
Howard E. Strassler, DMD
Professor, Division of Operative Dentistry
Department of Endodontics, Prosthodontics, and Operative Dentistry
University of Maryland Dental School