Area of Science:

• Dental Materials Science
• Restorative Dentistry
• Colorimetry

Background:

• Accurate shade matching is crucial in dental restorations.
• Understanding how composite thickness affects perceived color is essential for predictable aesthetic outcomes.

Purpose of the Study:

• To determine the critical thickness reduction of dentin shade composite required for perceptible and acceptable color changes in simulated dental restorations.
• To evaluate if different composite systems exhibit variations in color change thresholds based on thickness reduction.

Main Methods:

• Three composite systems were tested using layered dentin and enamel shade specimens.
• Sequential 0.1 mm reductions in dentin composite thickness were made, and color changes (∆E00) were measured.
• Opacity and color change thresholds for perceptibility (∆E = 0.81) and acceptability (∆E = 1.77) were calculated using regression analysis.

Main Results:

• Perceptible color changes occurred when dentin shade thickness was reduced to 2.0–2.4 mm.
• Acceptable color changes were noted with reductions to 1.1–1.4 mm.
• No significant differences in color change thresholds were found among the tested composite systems.

Conclusions:

• Reductions in dentin composite thickness below 0.6 mm did not result in perceptible color shifts.
• Clinically significant color changes were observed only with thickness reductions exceeding 1.6 mm.
• The thickness of dentin shade composite plays a vital role in achieving desired aesthetic results in dental restorations.