What is the PH at which initiation of caries begin ?
A. 4.3-4.5
B. 5.2-5.5
C. 4.9-5.1
D. 3.5-4.5
What is the PH at which initiation of caries begin ?
A. 4.3-4.5
B. 5.2-5.5
C. 4.9-5.1
D. 3.5-4.5