Evaluation of Radiopacity of Bulk-fill Flowable Composites Using Digital Radiography

Abstract

New flowable composites that may be bulk-filled in layers up to 4 mm are indicated as a base beneath posterior composite restorations. Sufficient radiopacity is one of the several important requirements such materials should meet. The aim of this study was to evaluate the radiopacity of bulk-fill flowable composites and to provide a comparison with conventional flowable composites using digital imaging. Ten standard specimens (5 mm in diameter, 1 mm in thickness) were prepared from each of four different bulk-fill flowable composites and nine different conventional flowable composites. Radiographs of the specimens were taken together with 1-mm-thick tooth slices and an aluminum step wedge using a digital imaging system. For the radiographic exposures, a storage phosphor plate and a dental x-ray unit at 70 kVp and 8 mA were used. The object-to-focus distance was 30 cm, and the exposure time was 0.2 seconds. The gray values of the materials were measured using the histogram function of the software available with the system, and radiopacity was calculated as the equivalent thickness of aluminum. The data were analyzed statistically (p<0.05). All of the tested bulk-fill flowable composites showed significantly higher radiopacity values in comparison with those of enamel, dentin, and most of the conventional flowable composites (p<0.05). Venus Bulk Fill (Heraeus Kulzer) provided the highest radiopacity value, whereas Arabesk Flow (Voco) showed the lowest. The order of the radiopacity values for the bulk-fill flowable composites was as follows: Venus Bulk Fill (Heraeus Kulzer) ≥ X-tra Base (Voco) > SDR (Dentsply DeTrey) ≥ Filtek Bulk Fill (3M ESPE). To conclude, the bulk-fill flowable restorative materials, which were tested in this study using digital radiography, met the minimum standard of radiopacity specified by the International Standards Organization.

Radiopacity of Methacrylate and Silorane Composite Resins Using a Digital Radiographic System

“…According to the recommendations of the International Organization for Standardization (ISO 40490:2009) [ 16 ] restoration materials measuring 1 mm in thickness should have radiopacity equal to or greater than the same thickness of aluminum. According to results found in the literature [ 12 ] all tested materials followed the ISO 4049 standard and showed radiopacity value greater than a 1 mm step of the penetrometer scale, because it is known that the radiopacity material may vary according to the material thickness [ 17 ]. In the present study 10 mA, 65 kVp and 0.1 s were applied.…”

“…The composition of the composite resin has great influence on the radiopacity of the material [ 17 ]. To increase the radiopacity of dental restoration materials, elements with a high atomic number, such as barium, strontium, zirconia, and zinc, have been added to the inorganic phase of resins with no adverse effects on the other properties of these materials.…”

“…Regarding the flow materials (low viscosity) used in this study, both low polymerization shrinkage (Surefil SDR flow) and conventional resin (FIltek Z350 flow) presented similar radiopacity to the high viscosity composite resin Filtek Z350, which contains nanoparticles. According to the manufacturer, SureFil SDR contains radiopaque components, giving it satisfactory radiopacity based on the criteria established in the literature [ 5 , 17 ]. The flow resin composites are made with inorganic particles of the same size as those in resin composites, but with lower compactness, resulting in lower viscosity [ 1 ].…”

Overviews on the Progress of Flowable Dental Polymeric Composites: Their Composition, Polymerization Process, Flowability and Radiopacity Aspects

“…A study applying digital radiography proved that for all investigated bulk-fill flowable composites, significantly higher radiopacity values were evident in comparison with those of enamel, dentin and most of the conventional flowable composites (among them a self-curing material too). The majority of the manufactures’ values were close to the results of the studies; thus, it is concluded that the radiopacity data provided by the manufacturers can be trusted [ 59 ]. The incorporation of 3% n -TiO 2 in flowable composite slightly diminished the radiopacity values.…”

Oxidative Alteration in Gingival Fibroblast Cells Induced By Bulk-Fill and Conventional Flowable Composites

“…However, there are some problems associated with their poor mechanical properties, lower filler content, polymerization shrinkage and weak adhesion (1,3). Manufacturers have recently introduced new generation flowable composites, so called higher filler loading flowable resin composites, bulk-fill flowable composites and self-adhering flowable composites for elimination of negative effects and improving clinical requirements (3,5). Higher filler loading flowable resin composites for posterior restorations have better wear resistance compared with some resin composites (6).…”