Mechanical properties of denture base resin cross-linked with methacrylated dendrimer

Objectives

The aim of this study was to investigate the mechanical properties of denture base resin cross-linked with methacrylated dendrimer.

Methods

The test specimens (3 mm × 10 mm × 65 mm) were fabricated from autopolymerizing resin with the powder/liquid ratio of 10 g/7 ml. The monomer liquid of resin was applied with the mixture of methylmethacrylate and crosslinker dendrimer (DD1) or crosslinker ethyleneglycol dimethacrylate (EGDMA) with five different volume percentages (vol%). The dendrimer crosslinker in this study is a methacrylated molecule (MW = 3617 g/mol) with 12 methacrylate groups. Quantity of crosslinkers varied from 1.1 to 9.1 vol%. The specimens (n = 8/group) were polymerized in distilled water maintained at 55 °C under pressure of 0.4 MPa for 20 min. Test specimens were stored dry at room temperature before testing. The flexural strength (MPa) and flexural modulus (GPa) was measured with three-point bending test at a crosshead speed of 5 mm/min. Surface microhardness (MHN) of matrix area of polymer (n = 8/group) was measured with a load of 245.3 mN by 10 s. Data were analyzed with two-way ANOVA.

Results

ANOVA showed that the addition of DD1 had a significantly higher effect (p < 0.05) on flexural modulus and hardness of matrix area than EGDMA but on flexural strength (p > 0.05). The effect of quantity differences of crosslinker was statistically significant only on flexural strength (p < 0.05).

Significance

The results of this study suggest that dendrimer-crosslinked resin gives better stiffness than that of EGDMA.