This work deals with the bulk damage to p-type silicon pad sensors, for which the knowledge of radiation-induced defects is limited at present. Therefore, three differently grown p-type bulk materials were irradiated with 23 MeV, 188 MeV and 23 GeV protons. In order to study the impact of the bulk damage to sensor properties, I-V and C-V-f measurements were performed during annealing studies. Additionally, TSC spectra were analyzed with a revisited SRH statistics, modified to account for the cluster-related defect contributions. A proton-energy dependent introduction of defects is found, except for cluster-related defects. Moreover, shallow defects are present in different concentration according to the material type. A correlation between the leakage current and the concentrations of three defects (the V2, E5 and H(220K)) is notable during annealing studies. It is not excluded that the changes in the space charge in p-type sensors are mainly due to the E(30K) and the BiOi) defects, and three main deep acceptors (namely the H(116K), H(140K) and the H(152K)).