Document Type


Date of Degree

Spring 2019

Access Restrictions

Access restricted until 07/29/2021

Degree Name

PhD (Doctor of Philosophy)

Degree In

Oral Science

First Advisor

Maia, Rodrigo R

First Committee Member

Brogden, Kim A

Second Committee Member

Skiff, Frederick N

Third Committee Member

Dawson, Deborah V

Fourth Committee Member

de Mattos Pimenta Vidal, Cristina


The resin composite (RC) layering technique attempts to replicate the natural structure of teeth by using an opaque dark layer (replicating dentin) covered with a translucent layer (replicating enamel). Previous studies have confirmed that the shade of dentin and the thickness and translucency of the enamel layer are essential factors in the color of natural teeth. However, these findings have never been validated with the RC layering technique.

RC layering technique provides superior esthetic results; however, the chemical composition and optical properties of RC are different than natural dentition. Hence, the color interaction between the enamel and dentin RC layers makes the color of the final restoration unpredictable.

The objective of this dissertation was to determine the color interaction between the enamel and dentin layers using a unique and novel sample design: a double-layered RC with variant enamel thicknesses (0.5, 0.7, 1.0 mm) and variant dentin shades (lighter and darker shades). The study methods tested the interaction between certain shades as per manufacturers’ instructions to reproduce certain shades. Two different RC systems that are fundamentally different with regards to their shading system were tested in this study. A potential link between the color of the double layered RC samples to the VITA 3D master shade guide which has been overlooked by clinicians and researchers, have been investigated in this study. Research aims included validating the sample design we have incorporated into our studies. Furthermore, other aims investigated the double-layering techniques in comparison to their corresponding shades from the VITA classical and VITA 3D Master shade guides. The outcomes of this study are clinical recommendations on the optimal combination of dentin shades and enamel layer thicknesses to use in order to best match the color of natural teeth.


Color, Double Layered Restoration, Resin Composite, Shade


xxi, 163 pages


Includes bibliographical references (pages 156-162).


Copyright © 2019 Eman Hani Ismail

Available for download on Thursday, July 29, 2021