Perspectives on the Measurement and Clinical Meaning of Translucency
One basic recommendation in prescribing an all-ceramic system for a particular clinical case involves choosing one that allows the development of an appropriate opacity/translucency (or Munsel “value”) for that patient. For many years all-ceramic systems tended to “bunch” at either end of the translucency-opacity range of natural teeth and highly esthetic results depended much on the artistic abilities of the ceramist. All-ceramic systems today more uniformly populate this range, with some providing life-like vitality as monolithic structures. Additionally, there has been a blurring of distinctions among “esthetic” and “strong” ceramics. Traditional measurements of translucency have involved contrast ratio techniques. Comparative data for contrast ratio and true translucency measurements will be presented. Recent literature on the measurement of translucency in natural teeth will be reviewed. This then informs the discussion of a long-missing next step: providing translucency data as part of the “shade” prescription.
• Review dental ceramics from the perspective of translucency and opacity-strength relationships;
• Compare data obtained by contrast ratio techniques and direct translucency measurement for a number of modern ceramics;
• Review recent literature on the translucency of natural teeth and some clinical perspectives on the role of translucency in achieving life-like esthetics.
J. Robert Kelly teaches graduate prosthodontics and biomaterials and is Director, Centers for Dental Clinical Research and Advanced Technology Integration at the University of Connecticut Health Center. His academic credentials include the D.D.S. (The Ohio State University), an M.S. in dental materials science (Marquette University), the D.Med.Sc. in oral biology and a Certificate in prosthodontics (Harvard University). He has served on the Council on Scientific Affairs of the American Dental Association (ADA), is Convener of the International Standardization Organization working group responsible for dental ceramics, Vice Chairman of the ADA Standards Committee on Dental Products and President, American Academy of Fixed Prosthodontics. Dr. Kelly has received awards for biomedical research (Harvard), research and post-graduate education (Assoc. Military Surgeons of the U.S.) and as a clinician/scholar (Amer. College of Prosthodontists). He has contributed to dental, engineering, and medical literature, holds five patents, frequently lecturers before national and international dental and engineering organizations, still does some of his own porcelain and keeps his fingers wet practicing fixed prosthodontics.