Faculty and Staff, Prosthodontics, Research

Wright Co-Authors Study Showing Shade-matching for Crowns Impacted by Gum Color

Dr. Robert Wright, chair of the Department of Prosthodontics, was recently published as a co-author to a study published in the Journal of Dentistry. The study, completed prior to his arrival at UNC this July, examined the effect of gingival (gum) color on shade-matching for ceramic tooth restorations. It was published under the title “Optical effects of different colors of artificial gingival on ceramic crowns.”

“This study is the first of its kind sincee interaction between gum color and ceramic tooth shade has never thoroughly been looked at in a study,” said Wright. “Unfortunately, not examining this earlier has led to errors in both shade selection and shade replication, both of which are not ideal for the patient receiving the ceramic crowns. As such, we wanted to examine the impact of changing the gingival color on the appearance of the ceramic crown shade.”

To complete the study, the group of researchers used 31 all-ceramic crowns of varying shades and six different artificial gingival shades. Using a tool called a spetrophometer, shade measurements were taken of crowns with each of the six artificial gingiva. The control gingiva used was the pink gingival, and each crown was compared between the test groups and the control gingiva. In reviewing the measurements, significant differences were found in the values of all six gingival color groups and between the gingival groups and the ceramic crowns.

“Essentially, what we found was what we expected: different colors of gingival generate detectable shade differences,” explained Wright. “Our research shows that the use of artificial gingival that closely matches the patient’s own gingival will provide ceramists the best experience in matching and replicating tooth color for the ceramic crown.”

The study was completed during Wright’s time at Harvard University School of Dental Medicine. The lead author on the study was Dr. Jian Wang who holds joint appointments at Harvard University School of Dental Medicine and West China College of Stomatology. Other authors include Harvard University School of Dental Medicine faculty Drs. Jin Lin, Mindy Gil, John D. Da Silva and Shigemi Ishikawa-Nagai. The research was funded by Olympus and the Harvard School of Dental Medicine Department of Prosthodontics.