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Properties of a Bulk-Fill Flowable Composite Resin with High Depth of Cure

Dental composite resins are types of synthetic resins which are used in dentistry as restorative material or adhesives. It’s also more recently used as a dentine replacement material. 

SDR (Smart Dentine Replacement, Dentsply) is a flowable, high-resin composite material designed to minimize the effect of the high shrinkage through the use of a flexible monomer. It has an increased depth of cure due to increased translucency which can have an adverse impact on aesthetics in some clinical situations. In this paper, the authors conducted an in vitro study to investigate the properties of a bulk-fill flowable resin restorative material.

Tests were carried out on Surefil SDR (Smart Dentin Replacement) and two other commonly used resin-based composite materials (XRV Herculite, Kerr and Spectrum TPH, Dentsply) including: depth of cure according to ISO 4049, degree of cure using Fourier Transform Infrared Spectroscopy (FTIR), compressive strength using a Universal testing Machine, water uptake, interaction with Coca-ColaTM and analysis of thermal transitions using Differential Scanning Calorimetry (DSC). 

The results showed that SDR exhibited a high depth of cure at 4.0 mm and no difference in degree of cure in comparison with the other two dental composites. Compressive strength results varied between materials but were significantly lower for SDR (P < 0.05). Water uptake was similar for all materials but elution was significantly greater for SDR and interaction with Coca-Cola showed greatest change for SDR. In addition, a disadvantage of SDR was that it cannot be used alone as a restorative product to completely fill deep cavities as it was a lining material rather than a restorative filling material.

In conclusion, there are some statistically significant variations between the physical properties of the materials which are attributed to the monomer type and lower amount of filler in the flowable composite that may explain the published clinical outcomes.

Article by Rimi Gill, et al, from UK.

Full access: http://mrw.so/4hyAkU

Image by serena ponting, from Flickr-cc.

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