N. Summer Lerch, DDS, FAGD, AAACD
The field of dentistry is evolving. Traditionally, impression-taking has involved applying astringents and hemostatic agents, packing cord, and forcibly challenging the gingival tissues. Today, however, a unique new system has made these time-consuming and sometimes harmful processes obsolete. The NoCord VPS™ self-retracting impressioning system from Centrix, Inc. (centrixdental.com), a company led by dental innovator Dr. William B. Dragan, brings a highly effective “gentle displacement” impression material to the dental marketplace. This system allows cosmetic-minded clinicians to easily take highly accurate impressions while causing no harm to sensitive gingival tissues. NoCord VPS affords a clean capture without extra tissue retraction, providing an easy-to-read margin and allowing a perfectly fitted restoration. Moreover, there is no need to learn a new procedure, as a traditional wash-and-tray technique can be used.
Key Takeaways
• NoCord is a one-step impressioning and retracting system designed for simple, noninvasive, and accurate impressions. It spares gentle gingival tissues the trauma of packing cord.
• With no cord to pack and without the need for a separate retraction procedure, the system saves time and money for the dentist and staff.
• NoCord VPS Wash retracts tissue away from the tooth and achieves hemostasis and accurate marginal detail. Good color contrast makes reading the margins easy. NoCord VPS MegaBody tray material has a unique setting profile that enables it to effectively “drive” the Wash into the sulcus, causing retraction.
About the Author
N. Summer Lerch, DDS, FAGD, AAACD
Center for Esthetic Dentistry, LLC
New Haven, Connecticut
Figure 1
Fig 1. The patient presented complaining of a dark tooth in her lower arch that was “ugly” and “keeps me from smiling,” she said. After a full examination, clinical radiographs, and a sequence of American Academy of Cosmetic Dentistry accreditation photographs, it was determined that a simple porcelain crown over the existing root canal-treated tooth, No. 24, would be a viable, esthetic solution.
Figure 2
Fig 2. The process began with a Zoom!® whitening (Philips, usa.philips.com) treatment, which is a favorite practice of the author before performing cosmetic dental work. Five days later, the initial shade was taken before starting the restorative procedure. Shade OM-1 was chosen.
Figure 3
Fig 3. Tooth No. 24 was then prepared for a full crown with a lingual supragingival margin.
Figure 4
Fig 4. Enough circumferential reduction was achieved for beautiful esthetic contours to be developed.
Figure 5
Fig 5. After cleansing with a 35% hydrogen peroxide formula (Superoxol, Sultan Healthcare, sultanhc.com) and expressing some impression material to bleed the cartridge and ensure proper mixing, a full-arch impression was taken using NoCord VPS. Retraction cord was not used, thereby avoiding gingiva trauma from the packing procedure.
Figure 6
Fig 6. NoCord VPS Wash was expressed for set check.
Figure 7
Fig 7. The author prefers the NoCord VPS impression kit from Centrix. NoCord VPS Wash material was syringed around the tooth and then air-blown before a second layer was added. This process fully covered the preparation, ensuring there was enough material to capture the complete margin.
Figure 8
Fig 8. The tray was filled with NoCord VPS MegaBody tray material then placed over the preparation, driving the wash into the sulcus and creating the space necessary to capture complete marginal detail. The impression was removed from the mouth at 4:45 minutes.
Figure 9
Fig 9. Going from the preparation to the final impression was simple and fast. Contrast was clear, and margins were easy to read. All steps of the procedure were accomplished using one product, with no need for extra bottles, cords, or hemostatic materials. The ease of use, combined with the excellent final results, made taking the impression a pleasure.
Figure 10
Fig 10. Final shade was taken of the prepared tooth. Note how healthy the tissue looked, as there was no trauma or reddened or impacted gingival tissue. Further, even with an endodontically treated tooth, no anesthetic was needed for any portion of the procedure, an added benefit for the patient and staff.
Figure 11
Fig 11. Two weeks after preparation and impression, the provisional was removed. Note the health of the tissue.
Figure 12
Fig 12. The patient was now ready for the try-in and possible cementing of her new porcelain crown. At the initial try-in the crown fit perfectly, with margins and contacts exactly where they should be, due largely to the NoCord impression material.
Figure 13
Fig 13. The tooth had low value—ie, it was too gray. Therefore, a more opaque, creamy white try-in paste was placed, which helped improve the esthetic concern. A final try-in would show that the tooth was ready to be cemented.
Figure 14
Fig 14 and Fig 15. After patient approval, the No. 24 porcelain jacket crown was permanently cemented with a full-etch technique using Variolink® cement (Ivoclar Vivadent, ivoclarvivadentus.com). The patient was happy with the results, knowing she could smile easily and gracefully.
Figure 15
Fig 14 and Fig 15. After patient approval, the No. 24 porcelain jacket crown was permanently cemented with a full-etch technique using Variolink® cement (Ivoclar Vivadent, ivoclarvivadentus.com). The patient was happy with the results, knowing she could smile easily and gracefully.