Leitune, Vicente Castelo BrancoSchiroky, Priscila RaquelGenari, BrunaCamassola, MelissaLucca S, Felipe AntonioSamuel, Susana Maria WernerCollares, Fabrício Mezzomo2020-01-022020-01-022019-09Leitune Vicente Castelo Branco, Schiroky Priscila Raquel, Genari Bruna, Camassola Melissa, Lucca S Felipe Antonio, Samuel Susana Maria Werner, Collares Fabrício Mezzomo. Nanoneedle-like zinc oxide as a filler particle for an experimental adhesive resin. Indian Journal of Dental Research. 2019 Sep; 30(5): 777-7820970-92901998-3603http://imsear.searo.who.int/handle/123456789/192316Aim: The aim of this study was to develop an experimental adhesive resin with nanoneedle-like zinc oxide (N-ZnO), an inorganic filler, that could avoid particle agglomeration and lead to a homogeneous stress distribution within the material and characterize it. Materials and Methods: N-ZnO particles obtained by a thermal evaporation technique were characterized regarding size and surface area and added at 0 (control), 1, 2, 5, and 10 wt%, to an experimental adhesive resin. The following experimental adhesive resins' properties were assessed: radiopacity, contact angle to conditioned enamel and dentin, color, degree of conversion, flexural strength, resistance to degradation, and cytotoxicity. Statistical analysis was performed using one-way ANOVA and Tukey's post hoc test and paired Student's t-test. Results: Particles presented a mean particle size of 40 nm and a specific surface area of 16 m2/g. N-ZnO10%showed an increased radiopacity when compared to N-ZnO0%. Contact angles were significantly higher for N-ZnO10%at enamel and N-ZnO2%, N-ZnO5%, and N-ZnO10%at dentin. All groups showed color change when compared to N-ZnO0%. Higher the N-ZnO concentration, lower the degree of conversion. There were no significant differences between the groups for flexural strength and resistance to degradation. The addition of N-ZnO showed no difference in cytotoxicity when compared to positive control, N-ZnO0%, and all groups showed higher values than negative control. Conclusions: N-ZnO possibly exceeded potential limitations due to particles' agglomeration and improved the transference and distribution of stress within the material. It could be effectively used as a filler for adhesive resins.Dentin‑bonding agentsnanoparticleszinc oxideJournal ArticleIndiaDepartment of Conservative Dentistry, Dental Materials Laboratory - LAMAD, School of Dentistry, Federal University of Rio Grande do Sul, RS, BrazilDepartment of Genetics, Laboratory of Stem Cells and Tissue Engineering, Brazilian Lutheran University, RS, BrazilDepartment of Materials, Laboratory of Ceramic Materials, Federal University of Rio Grande do Sul, RS, Brazil