Resulting from clinical observation the relations between acute and chronical pulpitis and pulpitis chronica clausa, regressive metamorphoses and pulpal biomorphose are examined by histological findings and the literature. The etiological, nosological and pathohistological differentiation of this process is discussed. With the rising up of endodontological therapy needs into the middle and higher age the chronical inflammatorical and biomorphological events are more important. Proposals for diagnostics, differentiation and in the role wainting up instead of a early therapy are made.