The effects of various fabrication techniques and materials on the quality of ultrathin laminate veneers were evaluated in a recent study, with a focus on two key factors: the manufacturing trinomial (technology, printer, and resin material) and veneer thickness (0.3 mm or 0.5 mm). Veneers were produced using additive manufacturing—via tilting stereolithography or digital light processing—or subtractive milling.

Researchers tested five printer–resin combinations and assessed three primary outcomes:

• Fabrication trueness (measured by root mean square [RMS] surface deviation)

• Internal fit (mean internal gap)

• Margin quality (rated microscopically using a 3-point scale)

Among the tested methods, veneers made with IRIX Plus resin (AM-IP) using tilting stereolithography (TSLA) consistently demonstrated the best overall accuracy and fit, with an average internal gap of 66.6 µm across both thicknesses. The AM-IP group also showed the lowest RMS deviation, indicating high surface trueness. A similar material, IRIX Max (AM-IX), also performed well—especially in marginal accuracy—but showed slightly higher intaglio deviations and internal gaps: 52.9 µm for 0.3 mm and 111.2 µm for 0.5 mm veneers.

In contrast, veneers fabricated with digital light processing (DLP)-based printing and resins such as VarseoSmile Crown Plus (AM-VS) and Tera Harz TC-80DP (AM-GR) resulted in the highest deviations and largest internal gaps, particularly at the thinner 0.3 mm thickness. These groups often exhibited prominent under- or overcontouring that could require chairside adjustment.

Subtractive milling (SM-TC) produced clinically acceptable results, with average internal gaps falling between the best-performing (TSLA) and worst-performing (DLP) groups. Notably, 0.3 mm veneers showed improved internal fit over 0.5 mm veneers, though fabrication trueness remained unaffected by thickness.

Margin quality was generally moderate across all groups. While thinner AM-IP veneers (0.3 mm) tended to have rougher margins (70% rated as “low”), milled SM-TC veneers at 0.5 mm received the highest margin quality ratings (70% “high”). Most other groups scored “moderate.”

The study employed a rigorous triple-scan protocol and 3D metrology analysis under standardized conditions. Despite differences in performance, all veneers tested fell within clinically acceptable thresholds. The authors concluded that both the 3D printer technology and resin composition significantly impact the accuracy and fit of ultrathin laminate veneers. The combination of TSLA printing and AM-IP resin yielded the most consistent and favorable results.

Further studies are recommended to evaluate long-term durability and aging effects of these materials in clinical use.

Source: Journal of Dentistry