The purpose of this clinical trial is to compare the effect of different direct pulp capping methods on human pulpal response in the terms of inflammation & dentinal bridge formation. Methods: Eight patients providing 32 sound first premolars are selected. As recommended by ISO / TC 7405 pulpal exposure will be performed through a class I cavity. Four groups of eight specimens each will be defined according to the pulp capping method. Group A, will receive chemical set calcium hydroxide (Dycal). Group B, will receive mineral Trioxide Aggregate (MTA) according to manufacturer's instruction. Group C, will receive MTA and after its primary setting, within 15 minutes, the cavity is restored in the same appointment. Group D, will receive Multical as a direct pulp capping agent. Specimens will be assessed in the terms of dentinal bridge formation, its appearance compared to natural dentin, its thickness and inflammatory pulpal response. The last item will be scored 0-3 in which 0 corresponds to none, 1 to minimal, 2 to moderate and 3 to severe inflammation. In case of an abscess or true tissue necrosis, a score of 4 will be given as recommended by ISO / TC 7405.