Influence of Different Materials for Extrinsic Characterization on the Properties of CAD-CAM Denture Base Resins: A Systematic Review of In Vitro Studies.

PURPOSE: The objective was to investigate whether extrinsic characterization composite/pigment influence the surface, mechanical, optical, and biological properties of resin-based CAD-CAM denture bases. MATERIALS AND METHODS: This systematic review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and was registered in the Open Science Framework (OSF (10.17605/OSF.IO/W25KU). An independent electronic search was conducted by 2 reviewers in PubMed/MEDLINE, Cochrane Library, Scopus, Web of Science, Embase, ProQuest, and OpenGrey to identify studies published up to July 2026. The focused PICO question was: Does extrinsic characterization composite/pigment influence the surface, mechanical, optical, and biological properties of CAD-CAM denture base resins? RESULTS: Six studies were included in this review. Nine extrinsic characterization composite/pigment were evaluated, including 3 low-viscosity (pigments) and 6 regular-viscosity (composite), along with 1 intrinsic characterization resin, applied at thicknesses ranging from 0.2 to 2.0 mm. Extrinsic characterization composite exhibited superior performance in terms of surface roughness, color stability, and flexural strength. In addition, these materials were associated with reduced fungal adhesion, particularly when followed by conventional polishing procedures, whereas extrinsic characterization pigments showed greater surface degradation and optical instability. CONCLUSIONS: Extrinsic characterization composite/pigments seem to influence the performance of CAD-CAM denture base resins. Extrinsic characterization composite (regular-viscosity) tended to exhibit more favorable optical, mechanical, and biological properties than extrinsic characterization pigments (low-viscosity).