Tooth Anatomy and Shade Selection
Posted on 05/29/2013
Natural teeth vary in shade (color) in all three axes commonly known as the X, Y and Z axis
1. Mesial-Distal (X)
2. Gingival - Incisal (Y)
3. Buccal/Labial - Lingual (Z)
Variation seems to be most pronounced on the Y plane, and as a result, standard communication between dentists and labs refer only to this plane.
The Y plane is divided into three zones (see picture below):
1. Gingival/Cervical (closes to the gum) - G
2. Body (middle) - B
3. Incisal (biting edge) - I
The gingival third of the tooth is typically the darkest and gradually becomes lighter as it reaches the incisal edge. However, as the X and Z axes can also impact tooth color, it is often the case that a single shade tab does not accurately capture all of the distinctive lines, or communicate the opaque or translucent qualities of the tooth.
In such cases, especially when attempting to match a single central, it is often recommended for the dentist to both take a digital picture and send the patient to the laboratory for custom shading. The laboratory may use a different set of shade tabs, or devices such as the Vita Easy Shade® Machine, to help determine the correct porcelain colors to use.
Picture from page 47 of Fundaments of Color - Shade Matching and Communication in Esthetic Dentistry published by Quintessence Publishing Co. Inc and written by Dr. Stephen J. Chu, Dr. Alessandro Devigus, Dr. Rade D. Paravina and Mr. Adam J. Mieleszko
1. Mesial-Distal (X)
2. Gingival - Incisal (Y)
3. Buccal/Labial - Lingual (Z)
Variation seems to be most pronounced on the Y plane, and as a result, standard communication between dentists and labs refer only to this plane.
The Y plane is divided into three zones (see picture below):
1. Gingival/Cervical (closes to the gum) - G
2. Body (middle) - B
3. Incisal (biting edge) - I
The gingival third of the tooth is typically the darkest and gradually becomes lighter as it reaches the incisal edge. However, as the X and Z axes can also impact tooth color, it is often the case that a single shade tab does not accurately capture all of the distinctive lines, or communicate the opaque or translucent qualities of the tooth.
In such cases, especially when attempting to match a single central, it is often recommended for the dentist to both take a digital picture and send the patient to the laboratory for custom shading. The laboratory may use a different set of shade tabs, or devices such as the Vita Easy Shade® Machine, to help determine the correct porcelain colors to use.
Picture from page 47 of Fundaments of Color - Shade Matching and Communication in Esthetic Dentistry published by Quintessence Publishing Co. Inc and written by Dr. Stephen J. Chu, Dr. Alessandro Devigus, Dr. Rade D. Paravina and Mr. Adam J. Mieleszko
