Pulpal disease can be classified into pulpal hiperemia, reversible and irreversible pulpitis and pulpal necrosis. Periapical pathology which is a subsequent development of pulpal disease can be acute or chronic (symptomatic or asymptomatic) apical periodontitis or apical absces which can again have an acute or chronic (symptomatic or asymptomatic) character in its course of evolution. The main characteristics of pulpal pain is deep, dull, intense pain which is either spontaneous or lingering after an irritation, poorly localized and possibly irradiating. Other diseases, that arise in the vicinity of the stomatognathic system (e.g. maxillary sinusitis, migraine, neuropathy of the cranial nerves), or develop systemically (e.g. miocardial infarction, sickle cell disease, neoplasm) can mimic pulpal disease and can lead to the faulty diagnosis of pulpal disease which can be the cause of an irreversible therapeutic measure, an unnecessary endodontic treatment that harms the patient and does not solve the basic health problem which has not yet been diagnosed. The differential diagnosis of pulpal disease includes periapical pathology with a broad spectrum of possible etiologies, which is precipitating in the periapical tissues and numerous diseases of the organism. These diseases could cause difficulties in the diagnostic process and can lead to some confusion to the practitioner.