Over the past two decades in the conferences, work shops, social media we are receiving a big amount of information about mechanical aspects of endodontic treatment: new instrument systems, working principal, devices. 
Dentists are training to get more practical skills. Unfortunately, there is very little information about the diagnosis of 
the disease, the selection of correct and patient-friendly treatment methods. Over the past decade, dentistry has undergone a trans-formative shift towards embracing minimally invasive procedures and objectives, with a particular emphasis on preserving pulp vitality. The subjectivity in diagnosing severity of pulpitis with the debatable efficacy of 
current diagnostic tests (thermal test, EPT), has prompted a quest for more reliable and non-invasive alternatives.
The purpose of diagnosis in endodontics is to determine the condition of a painful tooth and indentify the cause of the pain or disconfort, or another kind of pulp or periodontal pathology. Scientific knowledge in this field is very important and mandatory along with available clinical diagnostic devices. As a dentist we are still limited with diagnostic tools. 
Therefore here is very important the right interpretention of patient complains, radiographical images. In the lecture will be discussed about the clinical situations, where is essential to have a good academic knowledge in hysthology, 
disease pathology, differencial diagnosis in order to diagnose the pulp or periodonttal pathology and to select the right treatment method. In endodontics no any “simple” clinical case, because there is no identical tooth, no identical clinical case and each treatment is individual, chosen according to the clinical situation.