Is the radiopacity of CAD/CAM aesthetic materials sufficient?

The radiographic evaluation of 11 different resin composites

Radiopacities of dental materials used in restorations are very important in making the radiographic diagnosis. Therefore, the aim of our study was to evaluate the radiopacity of five single-shade and six simplishade resin composites with digital technique. Five different single-shade (Charisma Topaz One, Omnichroma, Clearfil Majesty ES-2 Universal, Vittra APS Unique, ZenChroma) and six different simplishade resin composites (G-aenial A'CHORD, Essentia Universal, OptiShade, Estelite Asteria, Filtek Universal, Filtek Z250) were used. For each group, five disk-shaped resin composites of 1 mm and 2 mm thicknesses were prepared. As a control, tooth slices with 1 mm and 2 mm thicknesses and a 99.5% pure aluminum step-wedge were used. The samples, tooth slices, and a step-wedge were placed on a photostimulable phosphor plate. Digital radiographs were taken from 30 and 40 cm distances (70 kVp, 7 mA 0.28 ms). The images were analyzed using ImageJ software to measure the mean gray values. Data were analyzed using SPSS 22 package program and Kruskal-Wallis H Test (p < 0.05). The highest radiopacity was seen in Filtek Universal at both distances and thicknesses. Omnichroma had the lowest radiopacity in all parameters. All specimens showed higher radiopacity than dentin. Except for Omnichroma 1 and 2 mm thick, Clearfil Majesty ES-2 Universal 2 mm thick, samples showed higher radiopacities than enamel (p < 0.05). The restorative materials tested were found to be more radiopaque than dentin. The samples passed the International Organization for Standardization for radiopacity values. The radiopacity values were affected by thickness and type of materials.

The radiopacity of single-shade composite resins: A comparative evaluation

OBJECTIVE

The aim of this study was to evaluate the radiopacity of single-shade composite resins with group and multi-shade composite resins via a digital image analysis.

MATERIALS AND METHODS

Disc-shaped (5 mm in diameter, 2 mm in thickness) specimens were prepared with one multi-shade (Estelite Sigma Quick-ESQ), four single-shade (Omnichroma-OC, Charisma Topaz One-CTO, Vitra Unique-VU, and ZenChroma-ZC), three group-shade (G-aenial Achord-GA, Optishade-OS, and Estelite Asteria-EA), and one posterior composite resin (Estelite Posterior-EP) (n = 3). A radiographic image of all the specimens, an aluminum step-wedge, and a 2 mm thick tooth section were taken. Mean gray values (MGV) of the specimens, enamel, and dentin were calculated by ImageJ software. Composition analysis was performed with EDS, and SEM images (×10,000) were obtained. The data were analyzed with Kruskal-Wallis and Post hoc adjusted Bonferroni analysis (p = 0.05).

RESULTS

The mean MGV of CTO, the highest of all test groups, was significantly higher than OC and dentin (p = 0.04 and p = 0.009, relatively). The lowest mean MGV was also observed in a single-shade group, OC. EDS analysis showed that the tested materials comprised various radiopaque elements.

CONCLUSIONS

All of the single-shade and group-shade groups exceeded the MGV value of dentin, which is clinically expected from any restorative material.

CLINICAL SIGNIFICANCE

The radiopacity properties of various single-shade composite resins which as a category is a rising trend in esthetic dentistry were investigated. It is important for clinicians to be aware of novel materials' physical qualities including radiopacity, a daily clinical criteria for restorative materials.

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

A review article has been conducted including the main research results and comments referring to flowable dental polymeric materials. To begin with, the synthesis and composition of this category of composites is discussed, revealing the major components of the commercial products in terms of chemistry and proportion. Later, the polymerization characteristics are unfolded regarding the reaction time and rate, volumetric shrinkage and depth of cure for both photocurable and self-curable composites. To continue, some perspectives of the pre-treatment or accompanying processes that a clinician may follow to enhance the materials' performance are described. Fluidity is certainly associated with the progress of polymerization and the in-depth conversion of monomers to a polymeric network. Last, the aspects of radiopacity and translucency are commented on, showing that all flowable polymeric composites satisfy the radiography rule, while the masking ability depends on the fillers' properties and specimen thickness. The reviewing article is addressed to all field scientists and practitioners dealing with flowable dental composites studies or applications.