The gingival portion of natural teeth differs in colour from the incisal portion because the :
A. Lighting angle is different
B. Gingival and incisal portions have different fluorescent qualities
C. Gingival area has a dentine background
D. Incident light is different
A. Lighting angle is different
B. Gingival and incisal portions have different fluorescent qualities
C. Gingival area has a dentine background
D. Incident light is different