What Materials Do You Use to Achieve Gingival Retraction, and How Do You Use Them?
Stephen D. Poss, DDS | Gary Radz, DDS | Christopher Pescatore, DMD
Stephen D. Poss, DDS, is an international lecturer on esthetic dentistry, sleep apnea, and temporomandibular joint disorder (TMD) and maintains a restorative and TMD practice in Brentwood, Tennessee.
Gary Radz, DDS, is an associate clinical professor at the University of Colorado School of Dentistry, the owner of Cosmetic Dentistry of Colorado, and the director of industry relations for SmileSource.
Christopher Pescatore, DMD, maintains a full-time practice dedicated exclusively to esthetic restorative dentistry in Danville, California, and is an international lecturer on state-of-the-art esthetic procedures and CAD/CAM techniques and materials.
Stephen D. Poss, DDS: Clinical dentistry presents many daily challenges. This is especially true with fixed prosthodontics. The average dental practice derives 40% of its annual production from crown and bridge procedures. These require multiple steps to achieve an accurate fit with long-lasting results. If the margins are supragingivally located, capturing them can be relatively simple. However, if the restoration has subgingival margins, the clinician must deal with managing the tissue, blood, and saliva to obtain an accurate impression. This is critical to the long-term success as well because today, most restorative procedures involve some form of adhesive dentistry.
In my practice, I examine the tooth/teeth requiring restoration and look for any way that I can to keep the margins following the gingival contours without encroaching on the soft tissue unless there is decay, an old restoration requiring removal, or an esthetic concern.
Before I start a procedure, I will also utilize the radiographs to determine if retraction is even necessary and if so, to what extent I will have to go to achieve an ideal impression. If there is extensive subgingival decay or a failing subgingival restoration that I am going to replace, then I may want to consider first using a mechanical method to remove the redundant tissue. This makes retraction much less difficult to obtain. Tissue removal can be accomplished with a bur, a scalpel, an electrosurgical unit, or a diode laser. Once the tissue has been removed, then retraction cord or retraction paste can be used to achieve the desired level of gingival displacement.
Because no two restorative cases are exactly the same, the clinician is left to determine the best method of achieving retraction based on the degree of challenge presented by each case. For my patients, if there is only slight bleeding and not much tissue to consider, I would use retraction paste or a smaller sized retraction cord. Fully understanding the needs of the case before beginning can better prepare the dentist and lead to a more positive outcome.
Gary Radz, DDS: In our office, we do not have a singular retraction method that we routinely use, but rather, a combination of several materials and techniques that we choose from depending on the individual situation.
Certainly, there is a time and place for traditional retraction cord, and we use it often when the situation calls for its use. Occasionally, we will use a double cord technique, frequently, we will use only a single cord, and in the right clinical situation, we will use only a partial cord in the limited area of the preparation requiring tissue retraction.
Our diode laser (ie, Picasso, AMD Lasers) is a critical part of our soft-tissue management protocol. We use it to remove diseased, inflamed tissue that may be overlying a margin. It is also a great tool to help deal with minor bleeding and maintain hemorrhage control.
The other tissue retraction tool that we use on a daily basis is a retraction paste. There are a number of these on the market now, and we have found them to be an invaluable tool. The ability of these materials to retract in a time efficient, atraumatic manner makes them another important part of our soft-tissue management protocol.
When taking impressions, we have two techniques that we use most often for tissue retraction. The first involves the placement of a very small diameter retraction cord followed by the application of retraction paste. The paste serves as a replacement for the second cord in the two-cord technique. The other technique involves the use of retraction paste only. This is our preferred method when we are using our digital impression device (ie, CS 3500, Carestream Dental).
In addition to preparing teeth for impressions, the other way that we use retraction pastes (and one that others may not have thought to try) is to displace the gingiva when bonding or cementing in definitive all-ceramic restorations. The use of retraction paste during the cementation of porcelain veneers has become one of our standard operating procedures.
Christopher Pescatore, DMD: When discussing how to optimize the use of retraction materials, we often forget that the best clinical scenario is one that requires no retraction material. With today's high strength all-ceramic materials and adhesive systems, we can now effectively place margins supragingivally and render them relatively invisible. That being said, it is often advantageous to protect the soft tissue when prepping a tooth or placing a restoration with an adhesive cement.
The standard has always been to employ some type of retraction cord, whether it involves a one- or two-cord technique, with or without some type of astringent, such as epinephrine, ferric sulfate, or something similar. This is a highly effective, albeit time consuming, technique to use in some situations. Then, almost 20 years ago, retraction paste materials entered the US market. Their ability to stop tissues from hemorrhaging as well as provide sufficient retraction has proven invaluable in many ways. The biggest advantage is time. When compared with cord placement, it only takes a fraction of the time to syringe a paste around a tooth and achieve the same hemostatic effect. The downside of paste retraction systems is their cost, which is significantly higher than that of retraction cord. Each clinician needs to evaluate whether the potential decrease in chair time will offset the additional cost.
I have found that using a paste retraction system is especially beneficial to provide the ideal adhesive conditions when placing all-ceramic restorations. Retraction paste helps to control any bleeding and prevents sulcular fluid from contaminating the teeth. Once rinsed away, an ideal field in which to perform an adhesive procedure is obtained.
Alternatively, placing cord is particularly advantageous over retraction paste when cementing or bonding in situations that the clinician wants to avoid the risk of cement or adhesive being retained below the margin. When adhesive cements become bonded to the root surface below the margin, they can prove difficult to remove and possibly result in patient sensitivity if later removal is attempted with a handpiece.
Oftentimes, I find that the best retraction protocol involves a combination, especially when working in the posterior region. I place a cord to protect the gingival tissue and employ a paste retraction system to provide additional retraction and achieve hemostasis.