The aesthetics and durability of ceramic laminate veneers in dentistry are dependent on various factors, including curing light intensity and the thickness of the veneer. A recent in vitro study published in Scientific Reports investigated the influence of these elements on the color stability and translucency of cemented laminate veneers after simulated aging.
The study, authored by Huifen Qian and colleagues from Yunnan Province, China, involved the fabrication of eighty ceramic disks using shade A3 of IPS e.max Press HT specimens, created in two thicknesses: 0.50 mm and 1.00 mm. The researchers aimed to assess how different curing light intensities, specifically at 700 mW/cm², 900 mW/cm², and 1100 mW/cm², along with ceramic thickness, affected the veneers' color stability and translucency.
The results demonstrated that both the thickness of the ceramic and the light irradiance significantly influenced color changes after aging, with the most notable shifts observed in the 0.50 mm thick specimens subjected to 700 mW/cm² light. Statistical analysis through two-way ANOVA confirmed the findings, indicating a clear relationship among these variables, with a p-value of less than 0.01.
To simulate real-life conditions, the lacquered samples underwent 5,000 thermal cycles between 5 °C and 55 °C, mimicking the temperature variations experienced in the mouth. After these cycles, the researchers recorded a marked decrease in translucency and a tendency for the veneers to darken and exhibit a yellowish hue, particularly affected by the lower curing light intensities.
The authors pointed out that color stability is vital in aesthetic dentistry, as the external factors triggering color changes include light exposure, moisture content, and the interaction of the veneers with dietary pigments. Notably, the study found that the resin cement’s color change, primarily underlined by its exposure to various conditions, significantly impacted the overall color stability of the cemented veneers, as opposed to changes in the ceramic material itself.
With a visual color difference of 2.16 demarcating an observable change, the findings of this research underscore the critical reliance on thorough and standard curing during laminate veneer application. Specifically, the cemented specimens showed noticeable color differences above clinical acceptance after aging, emphasizing the importance of achieving optimal light-curing conditions.
The delineation between the two thickness levels further accentuated that increased ceramic thickness led to enhanced stability of color over time. The thicker specimens exhibited an overall superior color performance during accelerated aging compared to the thinner counterparts.
In providing insight into how curing light intensity and ceramic thickness influence the longevity of aesthetic dental procedures, this study adds a meaningful contribution to the body of knowledge in restorative dentistry. As dental professionals continue to seek improved methods for ensuring the aesthetic appeal of laminates over time, these findings may inform best practices regarding curing techniques and material selection.
Overall, the researchers concluded that both curing light irradiance and ceramic thickness markedly impact long-term aesthetics in cemented laminate veneers, emphasizing the necessity for careful monitoring of curing conditions to maintain the desired aesthetic outcomes after aging.