跳至主要内容

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.

评论

发表评论

此博客中的热门博文

A Comparison of Methods Used to Determine the Oleic/Linoleic Acid Ratio in Cultivated Peanut (Arachis hypogaea L.)

Cultivated peanut ( Arachis hypogaea L.) is an important oil and food crop. It is also a cheap source of protein, a good source of essential vitamins and minerals, and a component of many food products. The fatty acid composition of peanuts has become increasingly important with the realization that oleic acid content significantly affects the development of rancidity. And oil content of peanuts significantly affects flavor and shelf-life. Early generation screening of breeding lines for high oleic acid content greatly increases the efficiency of developing new peanut varieties. The objective of this study was to compare the accuracy of methods used to classify individual peanut seed as high oleic or not high oleic. Three hundred and seventy-four (374) seeds, spanning twenty-three (23) genotypes varying in oil composition (i.e. high oleic (H) or normal/not high oleic (NH) inclusive of all four peanut market-types (runner, Spanish, Valencia and Virginia), were individually tested ...
发表评论
阅读全文

The Influence of Heated Soil in Crop of “Tamaris” Tomato Plants on the Biological Activity of the Rhizosphere Soil

Tomato is a plant with high heat requirements and sensitive to cold weather and frost. The optimum temperature for the growth of tomato plants is between 21˚C and 27˚C during the day and between 17˚C and 21˚C at night. The soil temperature is also very important for plant growth. The optimum soil temperature for tomato cultivation should be within the range 15˚C - 18˚C. Besides, the proper development of the root system depends on the optimal temperature of the soil. A temperature below 14˚C reduces and inhibits the growth of the root system and encourages the development of fungal and bacterial diseases. In this study, the authors aimed to evaluate the effect of heated soil on the population of bacteria, fungi and nematodes inhabiting the soil of tomato cultivar “Tamaris” growing in peat and coconut substrates. The experiment was carried out in 12 treatments and in 3 replications (one slab was one replication). The soils were tested in two different types of containers: cylinders...
发表评论
阅读全文

Effect of Proline Pretreatment on Grapevine Shoot-Tip Response to a Droplet-Vitrification Protocol

Proline is an α-amino acid that is used in the biosynthesis of proteins. Some studies have shown that proline has been accumulated in plants in response to biotic and abiotic stresses. Exogenous proline has thus been used for improving some plant cryopreservation protocols. Further enhancement of cryopreservation efficiency for  in vitro  grapevines could be expected if stresses linked to cryopreservation procedures could be reduced. In this study, the authors studied the possible beneficial effect of proline in grapevine cryopreservation. Single-node explants from  in vitro  grown grapevine plantlets ( Vitis vinifera  L. cv Portan) were cultured on shooting media (half-strength MS + 1 μM BAP) containing no proline (control) or 50, 500, or 2000 μM filter-sterilized L-proline. Shoot tips excised from these microshoots were subjected to a PVS2-based droplet-vitrification procedure. Control and rewarmed explants were grown on a recovery medium containing ...
发表评论
阅读全文