A ceramic core used for fabricating a hollow turbine blade for a turbine engine using the lost wax casting technique, the blade including calibrated dust-removal holes emanating from a top of at least one cavity and opening out into a bathtub of the blade, wherein each of the calibrated dust-removal holes is formed in a core portion of height that is determined to be sufficient to guarantee mechanical strength, the core portion including a through orifice of axis perpendicular to a longitudinal axis of the calibrated dust-removal hole and defining on either side of the through orifice firstly a core cylinder having a determined diameter corresponding to the dust-removal hole that is to be formed, and secondly a remaining core volume that is to be plugged after casting, such that the calibrated dust-removal hole is obtained without drilling and without using connection rods.