Purpose: To develop a novel resin for provisional prostheses using hyperbranched polyurethane acrylate (HBPUA) and triethylene glycol dimethacrylate (TEGDMA) with promising mechanical properties and low volumetric shrinkage.
Methods: Four groups including TIH3-0 (100 wt% TEGDMA), TIH3-30 (30 wt% HBPUA + 70 wt% TEGDMA), TIH3-60 (60 wt% HBPUA + 40 wt% TEGDMA), and TB-60 (60 wt% bisphenol A-glycidyl dimethacrylate + 40 wt% TEGDMA) were prepared and commercial Luxatemp (DMG) was used for comparison. Fourier transform infrared spectroscopy and gel permeation chromatography were used for material characterization. Mechanical properties including microhardness, flexural strength, flexural modulus, and load energy were measured before and after water immersion. Physical properties measurement included weight changes, solubility, water absorption, surface hydrophobicity, and volumetric shrinkage. Finally, biocompatibility was evaluated using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay.
Results: The number- and weight-average molecular weights of the HBPUA were approximately 870 and 1480, respectively. The addition of HBPUA to TEGDMA increased the mechanical strength considerably. Although the weight changes and water absorption of TIH3-60 were higher than those of Luxatemp, the microhardness, flexural strength, flexural modulus, load energy, solubility, shrinkage, and biocompatibility of TIH3-60 were either comparable or superior to those of Luxatemp.
Conclusion: Based on the findings of the present study, TIH3-60 has potential for development as a new provisional material.
Keywords: Hyperbranched polyurethane acrylates; Mechanical characteristics; Micro-hardness; Provisional material; Triethylene glycol dimethacrylate.