BackgroundThe oral condition in children undergoing oncohematological treatment can have a negative impact on the course of disease. Little is known about survival of tooth restorations in these patients. The aim of this study was to evaluate the longevity of restorations and sealants performed by Atraumatic Restoration Treatment (ART) in patients undergoing oncohematological treatment.MethodsART single surface restorations and sealants were performed in the experimental group (E), which comprised children (2–13 years old) undergoing oncohematological treatment, and in the control group (C), in which patients did not undergo such treatment. The same examiner evaluated the ART at 1, 3, 6 and 12 months after preparation, using the same criteria for restorations and sealants. ART was successful if the sealant or restoration did not need a repair in the follow-up assessment. Descriptive, bivariate and Cox’s proportional hazard analyses were performed at a significance level of 5 %.ResultsThe two groups, one including 24 children (E) and the other 14 children (C), received 101 and 52 ART procedures, respectively. The success rates were 95.0 % (E) and 100 % (C) at 1 month (P = 0.233); 81.2 % (E) and 92.3 % (C) at 3 months (P = 0.009); 72.2 % (E) and 80.8 % (C) at 6 months (P = 0.050) and 48.5 % (E) and 73.1 % (C) at 12 months (P = 0.001). The final Cox’s regression model for occurrence of ART failure needing repair did not show differences between groups (E: OR = 1.6, 95 % CI 0.8–2.9); primary teeth had a shorter survival than permanent teeth (OR = 2.1, 95 % CI 1.2–3.7).ConclusionsOncohematological treatment did not interfere with the longevity of ART restorations and sealants, which suggests the potential use of this technique in children undergoing chemotherapy.Trial registrationBrazilian Clinical Trials Registry (REBEC) RBR-2c3c52. Registered 5 June 2014. http://www.ensaiosclinicos.gov.br/rg/RBR-2c3c52/Electronic supplementary materialThe online version of this article (doi:10.1186/s12903-015-0110-y) contains supplementary material, which is available to authorized users.