Clin Oral Invest DOI 10.1007/s00784-005-0030-3 ORIGINAL ARTICLE Rodrigo Borges Fonseca . Carolina Assaf Branco . Paulo Vinícius Soares . Lourenço Correr-Sobrinho . Francisco Haiter-Neto . Alfredo Júlio Fernandes-Neto . Carlos José Soares Radiodensity of base, liner and luting dental materials Received: 16 November 2005 / Accepted: 13 December 2005 # Springer-Verlag 2005 Abstract The aim of this study was to determine the radiodensity of base, liner and luting dental materials and to compare them with human enamel and dentin. Four classes of materials were examined: conventional glass ionomers (CG)—Vitro Cem, Ketac Bond, Vidrion F, Vidrion C; resin- modified glass ionomers (RMGI)—Fuji II LC, Vitrebond; resinous cement (RC)—Rely-X ARC; and zinc phosphate cement (ZP)—Cimento LS. Five 2-mm-thick standard samples of each material and five 2-mm-thick enamel and dentin samples were produced. An aluminum step wedge served as control. Samples were positioned over a phosphor plate of Digora digital system, exposed to X-ray, and the radiodensity obtained in the software Digora for Windows 2.0. Data were submitted to Kruskal–Wallis and Dunnett multiple comparisons test (α=0.05). According to statistical analysis, the following sequence in degree of radiodensity could be seen among the groups: Cimento LS (ZP) > Vitro Cem (CG) = Fuji II LC (RMGI) = Rely-X ARC (RC) = Vitrebond (RMGI) > Ketac Bond (CG) > enamel = Vidrion F (CG) > Vidrion C (CG) = dentin. The presence of radiopaque fillers such as zinc, strontium, zirconium, barium, and lanthanium rather than material type seems to be the most important factor when analyzing material radiodensity. Almost all investigated materials presented an accepted radiodensity. Keywords Radiodensity . Dental materials . Dental hard tissues . Composition . Digital radiographs Introduction It is generally accepted that materials should be sufficiently radiopaque to be detected against a background of enamel and dentin, facilitating the evaluation of restorations in every region of the mouth and enabling the detection of secondary caries, marginal defects, contour of restoration, contact with adjacent teeth, cement overhangs, and inter- facial gaps [1, 6, 11, 12, 17, 18]. The radiopacity degree required for ideal clinical performance can vary within the same class of material [11]. In spite of that, if used as a liner or base, some authors consider that it should be equal or more than dentin to assure that the material would not be mistaken for carious dentin [13]; however, other authors consider that restorative materials need a degree of radiopacity slightly higher than that of enamel [5, 11, 12, 16, 17, 19]. Several factors may affect the radiopacity of dental materials, but the composition seems to be the most important one [11, 12, 16]. In addition, the material thickness [11, 12], the angulation of the X-ray beam, the methodology employed for evaluation [17], the type of X- ray film, the age of developing and fixing solutions [5], and the alteration in the power/liquid ratio [11] can also have an influence. Common methods for evaluation of density of radiographic images employ conventional X-ray films and densitometers [1–3, 11, 12, 16] or spectrophotometers [22]. Since 1987, alternatives to silver-halide receptors for intraoral radiographic imaging have included CCD-based systems and storage phosphor technology [7]. Digital intraoral radiography reduces patients’ exposure to X-rays R. B. Fonseca . L. Correr-Sobrinho (*) Área de Materiais Dentários, Faculdade de Odontologia de Piracicaba, Universidade Estadual de Campinas, Av. Limeira, n° 901, Caixa Postal 52, CEP 13414-903, Piracicaba, São Paulo, Brazil e-mail: sobrinho@fop.unicamp.br Tel.: +55-19-34125200 Fax: +55-19-34210144 C. A. Branco . A. J. Fernandes-Neto Department of Occlusion and Fixed Prosthodontics, Dental School, Federal University of Uberlândia, Uberlândia, Brazil P. V. Soares . C. J. Soares Department of Operative Dentistry and Dental Materials, Dental School, Federal University of Uberlândia, Uberlândia, Brazil F. Haiter-Neto Department of Oral Radiology, Piracicaba Dental School, University of Campinas, Piracicaba, São Paulo, Brazil