G Heydecke1, F Zhang, M E Razzoog
1School of Dentistry, University of Michigan, Ann Arbor, Mich 48109, USA.
This study examined how the color of dental restorations made with a double-layer system changes over time. The restorations were made from an aluminum oxide core and a porcelain veneer. After simulating aging for 300 hours, the color changes were measured. The results showed that the color remained stable within acceptable limits. This suggests that these restorations could be a good option for patients. However, more research is needed to confirm these findings in real-world use.
You might also read
Articles linked to this work by shared authors, journal, and citation graph.
Area of Science:
Background:
Color stability of dental restorations is essential for long-term aesthetic outcomes. Prior research has shown that conventional porcelain veneers may experience color shifts over time. However, the use of alumina cores with feldspathic porcelain veneers remains less studied. No prior work had resolved the specific color stability of this double-layer system under aging conditions. This gap motivated the current investigation. Understanding how these materials respond to aging is crucial for clinical adoption. Current methods simulate aging through accelerated protocols. The role of light exposure and thermal cycling in color change remains unclear. This study aims to address these uncertainties.
Purpose Of The Study:
The aim of this study was to evaluate the color stability of double-layer dental restorations after simulated aging. Specifically, the researchers tested simulated veneers made of aluminum oxide cores and feldspathic porcelain. The study focused on changes in color coordinates after 300 hours of accelerated aging. This simulation mimics real-world exposure to light and temperature fluctuations. The researchers wanted to determine if these restorations maintain acceptable color stability. The study also aimed to compare color changes across different shade groups. The need for this work arises from the growing use of alumina-based restorations. Clinical relevance depends on the long-term shade retention of these materials.
The study found that simulated double-layer veneers showed minimal color change after 300 hours of aging.
The veneers were made from aluminum oxide cores and All-Ceram porcelain in Vita shades A1 and B4.
The composite substrates simulated stained teeth to better mimic clinical conditions during aging.
A total color difference below 3 DeltaE units is generally considered clinically acceptable in dentistry.
Color was measured using a colorimeter before and after 300 hours of accelerated aging.
Main Methods:
The study used fifteen aluminum oxide disks divided into three groups. Five disks were veneered with All-Ceram porcelain in Vita shade A1. Another five were veneered with Vita shade B4. Five disks remained unfinished as controls. The disks were bonded to composite substrates simulating stained teeth. Color measurements were taken with a colorimeter before aging. Specimens underwent 300 hours of accelerated photothermal aging. The aging process included light exposure and thermocycling. Color changes were measured again, and statistical analysis used paired t tests.
Main Results:
Color changes in the test groups showed an increase in lightness and a decrease in chroma. The calculated total color differences remained below 3 DeltaE units. This threshold is generally considered clinically acceptable. No statistically significant differences were observed between pre- and post-aging measurements. The control group showed no measurable color change. The A1 and B4 shade groups exhibited similar stability patterns. The results suggest that these restorations maintain shade consistency. The findings support the potential use of this material combination in clinical settings.
Conclusions:
The study found that simulated double-layer veneers showed minimal color change after aging. The total color differences remained within clinically acceptable limits. These findings suggest that this restoration type may offer good shade stability. The results do not confirm long-term performance in actual clinical use. The authors propose that further clinical research is necessary. The study does not claim that these restorations are superior to other options. The findings are limited to the specific aging protocol used. The authors emphasize the need for additional validation in real-world conditions.
The authors propose that clinical research is necessary to confirm these in vitro findings.