INTRODUCTION AND OBJECTIVES
Dental restoration materials such as composite resins have a variable radiographic
density, which is not generally reported by the manufacturer. This density (feature)
is of great importance in radiological diagnosis, allowing to differentiate and compare
natural tissue with artificial and or injured structures.
This study aims to evaluate the radiographic densities of composite resins used at
the University when compared to the hard dental tissues.
METHOD
Nine composite resins used in the students’ clinic of the Faculty of Dentistry of the
University Andres Bello, of which only 3 manufacturers report their radiographic
density are evaluated. Each composite resin as two (2) cylindrical photopolimerised
samples of 2mm thickness and 1 mm in diameter were used. Upper bicuspids
(recent extraction), were obtained and used as 2 mm thick longitudinal samples. A
radiographic aluminum step wedge with increments of 1 mm thick on each step was
also used. Nine x-rays were taken with a digital image plate sensor (PSP). Each
radiograph included a tooth slice, and two-equal sample of one of the types of
composite resin and aluminum wedge. The obtained radiographic densities were
measured using the Digora 2.7 computer software.
RESULTS AND DISCUSSION
Four resins composite presented a density slightly less than enamel. One resin
composite presented a density greater than enamel. One resin composite presented
a density less than dentin. Four resins composite had a density significantly below
the enamel (p < 0,05).
CONCLUSIONS
All composite resins resulted to have a radiographic density less the hard dental
tissues meeting the standard ISO 4049. Resin composites with values of
radiographic density equal or less than the enamel are the most indicated as clinical
restorative material to perform a correct radiographic diagnosis. This density must
be reported by the manufacturer in the technical specifications of the material.