Effect of surface treatment methods on tensile bond strength of denture liner material and 3D printed denture bases

The growing use of 3-dimensional (3D) printed denture base materials presents challenges in bonding with resilient denture liner materials, as traditional protocols may not suit their surface properties.

The purpose of this in vitro study was to evaluate the effect of different surface treatments on the tensile bond strength between 3D printed denture base materials and a resilient denture liner material.

A total of 300 rectangular blocks (10×10×20 mm) were fabricated in 5 types of materials: a heat-polymerized polymethyl methacrylate (PMMA) and 4 types of 3D printed resins (Ivotion, Lucitone, APEX, and Dentca). The blocks were first thermocycled (5000 cycles, 5 °C-55 °C) and treated with either no surface treatment (control), alumina airborne-particle abrasion, or a chemical bonding agent. A 3-mm layer of Coe-Soft was applied between 2 blocks, and tensile bond strength was measured using a universal testing machine. Failure modes were assessed via SEM. Data were analyzed using 2-way ANOVA and the Tukey post hoc tests (α=.05).

Bond strength was significantly affected by both surface treatment and material type (P<.001). Mechanical treatment yielded the highest bond strength in APEX (0.28 ±0.01 MPa) and Dentca (0.28 ±0.04 MPa), while chemical treatment decreased bond strength in the PMMA, Dentca, and Lucitone groups. Ivotion showed no significant response to either treatment (P>.05).

Surface treatment and material type significantly influenced tensile bond strength. Mechanical surface treatment generally improved bonding, while chemical treatments showed inconsistent effects depending on the material.