A Comparative Study of Shade-Matching Reproducibility Using an Intraoral Scanner and a Spectrophotometer

Area of Science:

• Dental Materials Science
• Digital Dentistry
• Color Science

Background:

• Assessing the repeatability of digital tooth color-matching methods is crucial for accurate dental restorations.
• Two primary digital methods, intraoral scanners and spectrophotometers, were evaluated for shade determination.
• The study focused on resin composite restorations and acrylic teeth in light and dark shades, both before and after an aging process.

Purpose of the Study:

• To compare the repeatability and accuracy of two digital tooth color-matching devices.
• To evaluate the impact of an aging process on shade determination accuracy.
• To assess performance across different shades (light and dark) of resin composites and acrylic teeth.

Main Methods:

• Forty acrylic teeth (shades A1, A3) were restored with resin composite (shades A1, A3) in standardized Class V cavities.
• Aging was simulated using 120 hours of ultraviolet light exposure.
• Shade measurements were taken five times at baseline and after aging using a Trios 3Shape intraoral scanner and a Vita Easyshade Compact spectrophotometer under D65 illumination.

Main Results:

• Both devices demonstrated 100% repeatability for artificial teeth at baseline.
• After aging, trueness for artificial teeth (shade A1) was 80% for both devices.
• For Class V restorations, trueness varied: intraoral scanner (A1: 80%, A3: 60%) and spectrophotometer (A1: 60%, A3: 60%) at baseline.

Conclusions:

• Intraoral scanners and spectrophotometers are reliable for initial shade selection.
• The accuracy of these digital shade-matching devices diminishes following aging.
• Darker shades are particularly susceptible to reduced accuracy after aging.