Although scientific and technological advancements have enhanced the predictability of many dental procedures, the clinical techniques and products used for gingival retraction and hemostasis remain critical to the success of crown, bridge, and other restorative treatments. In particular, the retraction, hemostatic, and moisture control protocol undertaken when creating a clearly visible and unincumbered path to gingival margins and finish lines significantly affect efficiency, accuracy, and comfort during preparation and impression-taking procedures—whether they be conventional or digital.
Fortunately, retraction paste can be used to effectively displace the soft tissue and produce a localized hemostatic effect.1 A study comparing conventional corded to cordless paste retraction techniques found that nonimpregnated displacement cord was least effective for hemostasis and impression quality.2 Conversely, the same study found that using aluminum chloride-impregnated cord and using displacement paste were comparable for dilatation and impression quality, but retraction paste demonstrated better ease of use and hemostasis.2 Additionally, a more recent study analyzing the clinical effectiveness of different gingival retraction systems found that an aluminum chloride-containing paste produced the highest mean gingival retraction when compared to knitted retraction cord and expanding polyvinyl siloxane, and it also was effective in almost all analysis areas.3
Among available retraction pastes is an aluminum chloride-based paste that effectively widens and dries the gingival sulcus to establish the ideal conditions for accurate and successful digital or conventional impressions (Retraction Paste [VOCO]). Provided in 0.3-g unit dose capsules (sufficient, for example, for displacing up to 3 sulci) with an extra-long, thin, and flexible plastic tip, the astringent paste promotes simple and precise application directly into the sulcus (ie, up to 50% faster than conventional retraction cord), without the potential for tissue injury or discomfort.
A 68-year-old man presented with a fractured maxillary right molar (tooth No. 3) (Figure 1). Clinical and radiographic examination confirmed a fractured mesial/lingual cusp and recurring decay at the mesial, buccal, and lingual gingival margins.
The tooth had been directly restored many times and was crucial for posterior stabilization of his maxillary partial denture. The patient was informed and understood that additional direct restoration of tooth No. 3 would not provide predictable long-term function for either the tooth itself or his partial denture. After reviewing treatment options, the patient decided to proceed with a full-coverage zirconia crown restoration.
During tooth preparation, it became apparent that the mesial decay extended subgingivally. Therefore, periodontal probings were recorded (Figure 2) to determine biologic width and proper margin depth.4 The biologic width measured between 2.0 to 2.5 mm, making it imperative that the preparations would not extend beyond 0.5 to 1.0 mm subgingival. To mitigate inflammation, bone resorption, and periodontitis, a 2.0-mm dimension from the bottom of the epithelium junctional to the tip of the alveolar bone was essential.4
Following tooth preparation, bleeding around the sulcus was evident (Figure 3). Given the depth of the preparation and the need to avoid further removal of sulcular gingival tissue and violation of the biologic width, chemical retraction/hemostasis was necessary. An aluminum chloride-based paste (Retraction Paste) was the ideal solution to address this clinical situation (Figure 4).To place the retraction paste, the flexible, plastic, thin tip was inserted into and moved around the preparation sulcus subgingivally while simultaneously extruding the retraction paste (Figures 5 to 7). The material’s rheologic composition (ie, 2-stage viscosity) ensured initial flowability for easy, low-force application, followed by stabilization for predictable temporary displacement, moisture control, and hemostasis. The paste remained in contact with the sulcular tissue and was allowed to set for 2 to 3 minutes.
Pressure into the marginal sulcus was administered using a 2- × 2-in cotton sponge gauze (Figure 8), after which bleeding persisted from the mesial margin (Figure 9). Therefore, Teflon tape was rolled and pushed through the retraction paste into the sulcus (Figures 10 and 11). This further carried the paste into the sulcus, placing pressure on the sulcular tissue, mitigating the bleeding, and widening the distance between the tissue and the margin. The Teflon tape remained in place for 2 to 3 minutes (Figure 12).
Due to the material consistency of the high-contrast retraction paste, it was easily washed off for quick cleanup (Figure 13). Once the Teflon tape was removed, the finished preparation and surrounding gingival tissues demonstrated clear and clean margins (Figure 14), providing a readily visible and clear path for easy and accurate intraoral digital impression scans (Figure 15).
When temporary retraction of the gingival tissues surrounding preparation margins is required, VOCO Retraction Paste represents an alternative method for establishing the moisture control and gentle soft-tissue management essential for exact crown margins; ideal adaptation; and long-lasting, aesthetic restorations. Akin to a cord in a capsule, VOCO Retraction Paste can be used to provide a dry gingival sulcus prior to taking conventional or digital impressions, for undertaking cementation of temporary or permanent restorations, and for preparing Class II and V restorations. As illustrated in this case, it can be an essential element for ensuring a visible and unincumbered path to gingival areas during preparation and digital impression-taking procedures.
1. Radz G. The key to the perfect impression. Compend Contin Educ Dent. 2010;31(6):464-465.
2. Acar O, Erkut S, Özçelik TB, et al. A clinical comparison of cordless and conventional displacement systems regarding clinical performance and impression quality. J Prosthet Dent. 2014 May;111(5):388-94.
3. Kumari S, Singh P, Parmar UG, et al. Evaluation of effectiveness of three new gingival retraction systems: a comparative study. J Contemp Dent Pract. 2021 Aug 1;22(8):922-927.
4. Stafee AA, Zinov’ev GI. Dental preparation features by subgingival location of circular ledge. Stomatologiia (Mosk). 2012;91(2):49-50.
ABOUT THE AUTHOR
Dr. Simos received his DDS degree from Loyola University in Chicago and maintains a private practice, Allstar Smiles, in Bolingbrook and Ottawa, Ill. The founder and president of the Allstar Smiles Learning Center, Dr. Simos teaches postgraduate courses in comprehensive restorative dentistry and is a recognized leader in cosmetic and restorative dentistry. In addition, he lectures throughout the country and is an internationally published author on the use of today’s innovative techniques and materials in dentistry. He can be reached at email@example.com.
Disclosure: Dr. Simos reports no disclosures.