Clinical Performance and Survival Outcomes of Milled Versus Pressed Lithium Disilicate Veneers: A Systematic Review

The aim of this systematic review was to assess and compare the clinical performance, marginal adaptation, esthetic outcomes, and long-term survival of lithium disilicate veneers fabricated using computer-aided design and computer-aided manufacturing (CAD/CAM) and heat-pressed techniques. An electronic search was performed in PubMed, Scopus, and Cochrane Library databases on February 24, 2025. Keywords and MeSH terms related to "lithium disilicate," "CAD/CAM," "pressed veneers," "anterior teeth," and "laminate veneers" were used to identify relevant studies published between 2013 and 2025.

This review adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guidelines and was registered in the International Prospective Register of Systematic Reviews (PROSPERO Registration number; CRD420251003590). Randomized controlled trials, clinical trials, retrospective studies, case series, and ex vivo studies published in English were included. Eligible studies evaluated lithium disilicate veneers placed on anterior teeth with a minimum follow-up of 6 months and reported outcomes related to marginal adaptation, survival, esthetics, or patient satisfaction. Data extraction was performed by two reviewers independently. Risk of bias was assessed using the ROB 2.0, QUIN, and ROBINS-I tools, and the GRADE framework was employed to evaluate the quality of evidence.

A total of 401 records were retrieved, out of which eight studies were included after screening. Of these, five studies compared CAD/CAM and heat-pressed veneers, two evaluated CAD/CAM-only, and 3 focused on heat-pressed-only interventions. Two were ex vivo studies. Heat-pressed veneers demonstrated superior marginal adaptation in both clinical and laboratory settings. CAD/CAM veneers showed better internal fit and workflow efficiency. Long-term survival (up to 10 years) was higher in heat-pressed veneers, particularly in complex cases like fluorosis or anterior FPDs. Color match (ΔE values) was within clinically acceptable limits across all materials. Only one randomized controlled trial exhibited low risk of bias; the remaining studies ranged from moderate to high risk. GRADE assessment downgraded most outcomes to low or very low certainty due to study design limitations and heterogeneity.

Both CAD/CAM and heat-pressed lithium disilicate veneers offer satisfactory esthetic and clinical outcomes when proper case selection and bonding protocols are followed. While CAD/CAM techniques enhance reproducibility and efficiency, heat-press methods appear superior in marginal adaptation and long-term survival. Further well-designed randomized trials with standardized outcome measures are essential to strengthen current evidence.