To know the properties of dentin and pulp is very important for a clinician because without proper knowledge there is a risk of a wrong diagnosis and treatment.
When opening chamber, white floor at bur tip is still dentin, sometimes is pulp stone because of orifice calcification that should be removed by fissure bur. Dark brown floor with groove connected orifices is real pulp floor. Everytime finding orifices should assist Apex locator.