Exploring the influence of tooth, ceramic, and resin luting agent variations on laminate veneer optical characteristics: a prospective clinical investigation

Abstract

Objective: This study evaluated the influence of tooth shade, resin-based luting agent shade values, and ceramic thickness on the optical properties of CLVs.

Materials and methods: The study involved 16 participants who received 95 CLVs. CIE L*, a*, b* color coordinates were assessed with a clinical spectrophotometer. Variables considered were: luting agent value in three levels (high, medium, low); tooth shade before and after preparation in two levels (lighter and darker shades); and CLV thickness in two levels (< 1 mm, ≥ 1 mm). The color difference (ΔE₀₀) was analyzed under four scenarios, utilizing statistical methods suitable for non-normal distributions.

Results: Ninety-five CLVs (n = 95) were analyzed, ceramic thicknesses mean (SD) values were 0.70 (± 0.15) for < 1 mm group and 1.19 (0.20) for ≥ 1 mm group. ΔE₀₀ values ranging from 2.93 to 9.72, all exceeding the thresholds of perceptibility and acceptability. Significant variations were observed in optical outcomes based on the clinical variables studied, particularly showing that high-value luting agents are more effective over darker substrates (p = 0.043). Thicker ceramics significantly improved masking capabilities, demonstrating their critical role in esthetic treatments (p = 0.024). No significant differences were found regarding the tooth shade after preparation (p = 0.215).

Conclusion: The study confirmed that luting agent shade values and ceramic thickness, critically influence the final optical properties of CLVs. High-value luting agents and thicker ceramics effectively achieved acceptable color differences, especially over darker tooth substrates. These findings underscore the importance of carefully selecting materials and techniques to optimize optical outcomes in CLV restorations.

Clinical significance: Luting agent's value and ceramic thickness plays a critical role in achieving natural-looking ceramic laminate veneers, especially on darker tooth substrates. These factors significantly impact the final color matching and esthetic outcome.

Keywords: Ceramic laminate veneers; Color alteration; Esthetic restorations; Resin-based luting agents; Spectrophotometry.