Objectives: The permeability characteristics of dentin have been used in many in vitro studies to evaluate longitudinally the efficacy of various restorative and preventative procedures. The easiest way to evaluate dentin permeability is to calculate its hydraulic conductance (Lp) by fluid filtration method. There are researches on electronic hydraulic conductance measurement systems which can give more precise and reliable results of permeability of dentine than the classical system. To the authors' knowledge, there are no studies on bonding properties of restoratives to fluorotic primary teeth and dentin permeability of those teeth in the literature.