Critical Observations in Color Communication
Color matching is a difficult task and an ongoing issue between the dentist and the lab. A successful dental team is tasked with understanding all of the nuances that affect the final result and must know what to look for in order to fabricate the final restoration successfully. Although an order to fabricate a restoration for which the color desired is A2 for the gingival third, C2 for the middle third, and A1 for the incisal third is a common request for a laboratory, it really is a very poor description of the exact colors that are needed. This is because a standard shade guide has a basic color to the neck, then body dentin color, and finally an incisal color. The big question is what part of the A2 shade guide should I apply to what part of the restoration? In addition, the “A” color spectrum is not the same as the “C” spectrum. The “A” hue is orange and the “C” hue is olive color, so which one should be used in fabrication? What part of the C2 shade guide will be placed at what part of the restoration? For example, you could select a gingival neck color from a guide and create the entire body of the restoration from that color.
Another issue to highlight is that dentists need to know that if they select a color like A4 for a posterior tooth, the shade guide has an A4 body color and gray enamel. Many posterior teeth have an A4 body, but very light or white enamel. Based on this, the selection of color should be separated. In other words, the dentin color should be selected on its own, followed by the selection of an appropriate enamel shade. Teeth have at least two selective zones and in many cases three zones.
Other important factors in color selection are the type of restoration to be fabricated and the color of the preparation. This information is critical and can influence the selected color. Oftentimes, when a dentist prepares a case and sends it to the lab, the lab then asks what kind of material should be used. This question should be addressed before preparation, not after, so that the preparation is designed to accommodate the right material for the case. In many cases, the ideal solution is to create conservative restorations where minimal preparation is done and the restoration can be thin. By understanding the situation beforehand, the material used can be relatively translucent, and the match will be easier to achieve.
A photo of the adjacent teeth is one of the most helpful communication tools available. Using a photo, laboratories can clearly see the shape and anatomy, including surface anatomy. Surface texture is an important detail and, when placed correctly, adds a component to the nonstick factor as well as provides parallel curved lines (or imbrication lines) that white, horizontal stains can flow into where appropriate. Furthermore, photos can provide additional information regarding the fine details of the color and characterization. Oftentimes, small details such as horizontal white lines, crack lines, white highlights on the tip of the ridges, or occlusal stains will be depicted in the photo. This information can significantly add to the quality to the final restorations, so it is important to always take quality photographs and include them with each case.
While color matching remains one of the biggest challenges in dentistry, there are ways to provide additional information that can greatly improve results. Most laboratories that are fabricating restorations have a great understanding of color and what is necessary to help improve the final results. Clinicians who utilize this resource can help reduce the need for remakes and corrections, which will ultimately lead to greater patient satisfaction and an improved bottom line.
About the Author
Uri Yarovesky, CDT, is the owner and president of Opus One Laboratories, Inc.