Hard tissue fractures seem to occur more often in root canal treated compared with vital teeth. This phenomenon may be explained by three contributing factors: 1) the loss of tooth vitality and thus resulting in decreased sensitivity to occluding forces; 2) the reduction in total dentine mass by pulp access and dowel preparation; and 3) the chemical weakening of dentine induced by the agents used for root canal disinfection. In this literature review, the last of these issues is discussed. Structural and mechanical properties of normal and age-altered dentine are described, and some key mechanical parameters of dentine presented. Finally, chemical effects of current topical root canal disinfectants on dentine structure and mechanical integrity are discussed. Palabras clave: Ca(OH)2, dentine, EDTA, hypochlorite, root canal treatment