Medical and dental science continually evolve, with research shaping tomorrow's realities. In dentistry, myths and realities persist, especially concerning pulp lesions and endodontic treatments. While trial-and-error once guided methodologies, recent decades have seen a shift towards scientific support. However, leading endodontic journals primarily focus on technical aspects rather than disease processes. This imbalance has hindered the advancement of biologically based knowledge in clinical endodontics. Dentists often excel technically but lack biological awareness, perpetuating a schism between clinicians and basic scientists. Despite modest progress, much of the accumulated biological knowledge has yet to find widespread clinical application. Consequently, conflicting views on managing endodontic disorders persist. This book reviews and examines the background of some of the more significant issues that have been debated in the endodontic field in recent years and discusses controversies regarding the clinical management of the disease processes associated with the vital and the non-vital dental pulp.