Permeability of Dental Adhesives – A SEM Assessment Juliana Malacarne-Zanona Safira M. de Andrade e Silvab Linda Wangc Mario F. de Goesd Adriano Luis Martinse Eliene O. Narvaes-Romanie Andrea Anido-Anidof Marcela R. O. Carrilhod,f AbstrAct Objectives: To morphologically evaluate the permeability of different commercial dental adhe- sives using scanning electron microscopy. Methods: Seven adhesive systems were evaluated: one three-step system (Scotchbond Multi- Purpose - MP); one two-step self-etching primer system (Clearfil SE Bond – SE); three two-step etch-and-rinse systems (Single Bond 2 – SB; Excite – EX; One-Step – OS); and two single-step self- etching adhesives (Adper Prompt – AP; One-Up Bond F – OU). The mixture of primer and bond agents of the Clearfil SE Bond system (SE-PB) was also tested. The adhesives were poured into a brass mold (5.8 mm x 0.8 mm) and light-cured for 80 s at 650 mW/cm2. After a 24 h desiccation process, the specimens were immersed in a 50% ammoniac silver nitrate solution for tracer per- meation. Afterwards, they were sectioned in ultra-fine slices, carbon-coated, and analyzed under backscattered electrons in a scanning electron microscopy. Results: MP and SE showed slight and superficial tracer permeation. In EX, SB, and OS, perme- ation extended beyond the inner superficies of the specimens. SE-PB did not mix well, and most of the tracer was precipitated into the primer agent. In AP and OU, “water-trees” were observed all over the specimens. Conclusions: Different materials showed distinct permeability in aqueous solution. The extent of tracer permeation varied according to the composition of each material and it was more evident in the more hydrophilic and solvated ones. (Eur J Dent 2010;4:429-439) Key words: Dental adhesives; Hydrophilicity; Solvents; Nanoleakage. a Department of Prosthodontics, School of Dentistry, Federal University of Espírito Santo, Vitória, ES, Brazil. b College of Health and Agrarian Sciences – UNIME, Lauro de Freitas, BA, Brazil. c Department of Operative Dentistry, Endodontics and Dental Materials, Bauru School of Dentistry, University of São Paulo, Bauru, SP, Brazil. d Department of Restorative Dentistry, Dental Materials Division, Piracicaba School of Dentistry, State University of Campinas, Piracicaba, SP, Brazil. October 2010 - Vol.4 e Department of Morphology, Piracicaba School of Dentistry, State University of Campinas, Piracicaba, SP, Brazil. f Health Institute of Bandeirante University of São Paulo, GEO/UNIBAN, São Paulo, SP, Brazil. Corresponding author: Marcela R. O. Carrilho Rua Alagoas, 475, 13B, São Paulo, 01242-001, Brazil Phone: +55 11 83974904 Fax: +55 11 30917840 E-mail: marcelacarrilho@gmail.com 429 European Journal of Dentistry