06 May 2021

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Effect of light-cured luting agents on ceramic veneer color

Edoardo Mancuso

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In aesthetic dentistry, shade matching between restoration and the surrounding tooth structures is a key factor for its success. This aspect is particularly challenging for thin translucent ceramic laminate veneer restorations. To improve the shade matching, the luting agent shade may play a significant role in the final appearance of the veneer restorations. It also extremely important that the luted veneers maintain their color over time, and in this scenario, light-cured resin-based materials have shown to have better color stability as compared to self and dual-cured luting agents. 

To better define the role of luting agents in ceramic veneer restorations, Professor Boscato and her team have conducted a systematic review aiming to draw guidelines for stable shade matching of ceramic laminate veneer. 

Materials and Methods

In the review, a search of in vitro studies that quantitatively investigated the influence of light-cured luting agents on the color of laminate veneers was conducted. Four electronic databases were searched, and data regarding the effect of light-cured luting agent, ceramic systems, the effect of background, accelerated aging, and surface treatments on color change were collected.

Results

The search strategy adopted in the article resulted in 3630 studies after removing the duplicates. Then the evaluation of titles and abstracts resulted in 48 studies selected for full-text reading. Thus, 21 papers were identified as eligible and included in Prof. Boscatos’ systematic review.

Discussion

To estimate the degree of shade matching or the masking ability of cemented laminate veneers, the color difference (ΔE) is usually calculated between the reference color (the substrate), and the color of veneer + luting agent + substrate. However due to the heterogeneity in the calulation of the different ΔE in the studies selected, no metanalysis has been made in the review. In any case, from the analysis of the data, Professor Boscatos and her team have presented qualitative appraisals of the findings, regarding the masking ability of luting agents. 

The discussion chapter start with info on the masking ability of luting agents. It continues assessing that, when talking about masking ability an important factor to take into account is the veneer thickness. As a matter of fact, the ticker is the restoration, the least is the effect of the luting agent shade. 

The review continues stating that another important factor to consider in this regard is the translucency of a luting agent. From the studies analyzed, is emerged that white opaque luting agents reduce the translucency of the cemented veneers, thus likely increasing their masking ability; translucent and dental-shaded luting agents, on the contrary, have little to no effect on the translucency of the cemented veneers, thus little improvement in masking ability is to be expected.

Conclusion

The systematic review concludes that distinct shades and opacities of luting agent yield clinically visible color differences on laminate veneers, allowing excellent shade matching with adjacent teeth. Among the various shade options investigated in the paper, the final aspect of the aesthetic restorations was influenced more by the translucency and value of the luting agent than by its chroma and hue. It is then added that the effect of luting agent shade on the color of veneers is greatly affected by the thicknesses and opacity of the ceramic veneers, since these factors are related to the translucency of the ceramic. 

Wherever treating a patient in the aesthetic zone, a perfect shade matching is absolutely required to result in a successful restoration. A profound analysis of the substrate and on the residual dentin and enamel on the abutment is mandatory. Even if we are going to use an opaque luting agent, a thicker laminate veneer might be the right option, when a dark tooth is to be reconstructed.

For additional information: Influence of light-cured luting agents and associated factors on the color of ceramic laminate veneers: A systematic review of in vitro studies