Dialogic pedagogy is being promoted in science teacher education but the literature on dialogic pedagogy tends to focus on explicit voices, and so runs the risk of overlooking the important role that material objects often play in science education. In this paper we use the findings of a teacher survey and classroom case study to argue that there is a gap in the way that science teachers think about the role of materials and that this could be addressed by changes in the theory base of teacher training, augmenting the current constructivist and dialogic theory with the addition of new materialism in the form of Barad's "Agential Realism". Our findings suggests that science teachers do not regularly "explicitly" consider the relationship between the material resources they deploy and the dialogic learning taking place. We argue that science teacher training and professional development should pay more attention to the material-dialogic relationships in the learning that emerges in science classrooms.