The effect of hyper-branched polymers on the properties of dental composites and adhesives

Abstract With the emergence of commercial hyper-branched (HB) and dendritic polymers, having a three-dimensional (3D) morphology with high peripheral functionality, new opportunities have been created for formulating dental adhesives and composites with enhanced mechanical and physical properties. The objective of the present study was to investigate the properties obtained by incorporating HB and dendritic polymers into acrylate-based dental composite and adhesive systems. Four commercial HB polymers were evaluated: Polyamidoamine dendrimer, two dendripolyamides and HB polyesteramide. These were added to dental restorative glass filled prepolymers, based on BisGMA, HEMA and TEGDMA. The dendritic and HB polymers blended readily with the prepolymers. A significant effect of HB polyesteramide (HB1), addition (0.1–3.0 wt%) on the mechanical properties was shown. It was found that addition of 0.3 wt% (optimal value) of HB polyesteramide raised the compressive strength from 253±20 MPa to 386±20 MPa and lowered the linear shrinkage from 2.4±0.2% to 1.5±0.2 % (for a model dental composite formulation). It was shown that the HB polyesteramide added to the dental adhesive compositions increased the shear bond strength and enhanced the bond durability to a variety of dental surfaces. Keywords: DENTAL ADHESIVESDENTAL COMPOSITESHYPER-BRANCHED POLYMERSCOMPRESSIVE STRENGTHLINEAR SHRINKAGE