Radiopacity of different resin-based and conventional luting cements compared to human and bovine teeth

Abstract

This study evaluated the radiopacity of different resin-based luting materials and compared the results to human and bovine dental hard tissues. Disc specimens (N=130, n=10 per group) (diameter: 6 mm, thickness: 1 mm) were prepared from 10 resin-based and 3 conventional luting cements. Human canine dentin (n=10), bovine enamel (n=10), bovine dentin (n=10) and Aluminium (Al) step wedge were used as references. The optical density values of each material were measured from radiographic images using a transmission densitometer. Al step wedge thickness and optical density values were plotted and equivalent Al thickness values were determined for radiopacity measurements of each material. The radiopacity values of conventional cements and two resin luting materials (Rely X Unicem and Variolink II), were significantly higher than that of bovine enamel that could be preferred for restorations cemented on enamel. Since all examined resin-based luting materials showed radiopacity values equivalent to or greater than that of human and bovine dentin, they could be considered suitable for the restorations cemented on dentin.

Radiopacity of Dental Materials: An Overview

“…However, the elements that give the restorative material its radiopacity also decrease its translucency (14)(15)(16). Radiopaque particles also have negative effects, such as increasing thermal expansion and the hydrolization of silane bonding agents (32).…”

“…Several studies have revealed that the radiopacity level of dental materials is critical and should depend on the purpose of the dental restorative material being used (3,6,20,24). On the other hand, highly radiopaque materials may cause a Mach effect and result in false positive or negative discrimination (30).…”

“…The filler particles of magnesium oxide, zinc oxide, fluoroaluminosilicate glass, strontium, barium, and zirconium give the radiopaque property to polycarboxylate, zinc phosphate, and glass ionomer cements. The atomic numbers of the elements of aluminum, silicon, calcium, zinc, strontium, zirconium, and barium are 13,14,20,30,38,40, and 56, respectively. The radiopacity of a material increases alongside an increase in the particle ratio of those materials which have an element content with a high atomic number.…”

“…Radiopacity is a desirable property of dental materials, including direct-filling restorative materials (1-3, 5, 10-15), cavity liners (11)(12)(13)(14), core build-up materials (12,16), luting agents (3,13,(16)(17)(18)(19)(20), adhesive systems (21), root canal filling materials (10,22), provisional crown and bridge materials (23), and ceramic restorative materials (24,25). The localization of radiolucent dental materials may not be detected if they are aspirated or impacted in the soft tissue because of trauma or iatrogenic reasons (7,26,27).…”

Influence of Radiopacity of Dental Composites on the Diagnosis of Secondary Caries: The Correlation Between Objective and Subjective Analyses

“…4 For better diagnosis, a restoration needs to have a radiopacity similar to that of dental tissues. 3 Therefore, it has been recommended 3,5,6 that the restorative material be more radiopaque than dentin and, preferably, have a radiopacity closer to that of enamel. However, an increase in the restorative material's radiopacity can reduce secondary caries detection and increase the incidence of false-positive results.…”