Prevention of apical periodontitis begins with the evaluation of whether the pulp can be preserved or not. Endodontics as a discipline holds the key for providing optimal “pulpal care”. This chapter deals with the dilemma of correctly diagnosing the pulpal status in deep caries. It addresses the biological platform for understanding why the dentine pulp complex is able to produce a hard tissue barrier. Deep lesions with risk of pulp exposure during caries removal should be better defined by added information on progression stage and penetration depth, lesion activity and estimated length of progression time. Caries is the common reason for performing root canal treatments, particularly in vital cases, and is a main cause of pulp inflammation. Based on published data, it is possible to make simulated scenarios for establishing a cost-effectiveness analysis of various vital pulp therapies.