The tooth has been prepped and the next step is to make a final impression. Whether by conventional means (i.e., impression material) or via digital capture, capturing a precise final impression during a crown and bridge procedure (aka, C&B) is crucial. Getting that final impression is the most important point in translating the clinical situation to the lab for fabrication of the final prosthesis.
If only capturing a final impression was as easy as expressing some material around the tooth or waving a scanning device over the preparation. Often there is one more step in-between the finished prep and the making of a final impression. Tissue management is the nexus between the prepped tooth and the final impression – it is the important link that allows clinicians to more easily and predictably make an outstanding impression that will ultimately help produce an exquisite final outcome.
Tissue management in most cases is used to accomplish two main things: tissue retraction and hemostasis. There are several means of tissue retraction commonly used by dentists to create sufficient gingival retraction and marginal exposure for C&B impressions: mechanical, chemical, and surgical. Often a combination of these techniques is used. The most common form of mechanical tissue displacement practiced by dentists to record a fixed prosthodontic impression involves the use of gingival retraction cord.
The use of chemical agents such as epinephrine, aluminum chloride, and ferric sulfate, used alone or in combination with cords is often used to facilitate hemostasis. The agents can be supplied in the form of gingival retraction fluids, gels, and pastes, or as a part of local anesthetic solution (i.e., epinephrine).
To overcome the challenges of traditional mechanical retraction using retraction cord, gingival retraction paste has been introduced to produce the combined effect of tissue retraction and hemostasis and drying. Generally, clay-based to absorb moisture and coupled with an astringent, retraction pastes are designed to be placed into and around the gingival sulcus and within several minutes produce hemostasis and drying. When used with a compression cap (a cylindrical, dense cotton pellet) and direct pressure, retraction paste can also provide tissue retraction. Traxodent (Premier Dental) is a Hemodent Paste Retraction System that features a functionalized proprietary clay (Fig. 1). Compared to other kaolin-based clay systems, Traxodent’s clay delivers improved ion exchange of the astringent and because of its surface area provides “swelling” capacity for fluid control, drying, and gingival retraction.
Traxodent contains 15% aluminum chloride and comes in either pre-packaged syringes utilizing bendable metal tips, or unit doses with a slender plastic tip that fits into an autoclavable dispenser. Traxodent can be used in virtually any clinical situation in which control of bleeding is required and may even be used in conjunction with gingival retraction cord. The material is simply dispensed into the area around the prepared tooth followed by having the patient bite on a Retraction Cap (Premier Dental). After two minutes, the paste is removed by thoroughly rinsing the area with water. The area can then be gently dried leaving the tissue free of moisture and blood, and ideally prepared for the final crown and bridge impression.
Step 1. A 39-year-old male patient presented for a full coverage restoration on tooth No. 3. After removing a large existing DOL amalgam, a core build-up was placed with CompCore AF (Premier Dental). The treatment plan included a full contour, monolithic zirconia restoration (Fig. 2).
Step 2. Using Solo Diamond (Premier) premium diamond burs, tooth No. 3 was prepared for a zirconia restoration. At least 1mm of occlusal and axial reduction was prepared, with a smooth 90-degree shoulder finish line. The prepared margin ended equi-gingivally, except for the distal which extended sub-gingivally.
Step 3. Because of persistent oozing of blood and fluid around tooth No. 3, Traxodent retraction paste using a unit-dose capsule was used. After removing the individual capsule from the foil package and inserting it into the dispenser, the material was placed around the prepared tooth (Fig. 1 & Fig. 3).
Step 4. After placing the Traxodent retraction paste, a Retraction Cap was positioned so the patient could bite down and provide direct pressure to the area (Fig. 4). After approximately 2-3 minutes the Retraction Cap was removed, and the area was thoroughly rinsed with water. Hemostasis was achieved and the margins of tooth No. 13 were clearly visible (Fig. 5).
Step 5. The final impression for tooth No. 3 was captured using an iTero Element 5D scanner (Align Technology Inc.). After verifying the details of tooth No. 3 were captured successfully, a provisional was fabricated using Luxatemp Automix Plus (DMG America) and cemented using NexTemp Temporary Cement (Premier), and the patient was released. He was re-appointed in three weeks for definitive cementation of the final restoration.
Ask your Patterson Dental representative about available Traxodent products or order online at pattersondental.com.
Jason H. Goodchild, DMD, received his dental training at the University of Pennsylvania School of Dental Medicine. He is currently the Vice President of Clinical Affairs at Premier Dental Products Company (Plymouth Meeting, Pennsylvania) involved in developing innovative new products and educating clinicians to improve clinical practice. He is also Associate Clinical Professor in the Department of Oral and Maxillofacial Surgery at Creighton University School of Dentistry, and Adjunct Assistant Professor in the Department of Diagnostic Sciences at the Rutgers School of Dental Medicine. Dr. Goodchild maintains a private general dental practice in Havertown, Pennsylvania.
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