4. MOST OFTHE HARDTISSUE INTEETH
IS DENTIN,A SPECIAL CALCIFIEDTISSUE,
DERIVED FROM MESENCHYME.
5. THE DENTINE INTHE ROOT IS COVERED
BY A LAYER OF CEMENTUM, CALCIFIED
TISSUE DERIVED FROM MESENCHYME.
6. THETOOTH ISTHEN CONNECTEDTO BONE
BYTHE PERIODONTAL LIGAMENT,WHICH
HASWIDE BUNDLES OF COLLAGEN FIBRES,
AND IS EMBEDDED IN BONY RIDGE
CALLED ALVEOLAR RIDGE.
7. THE CROWN IS PROTECTED BY LAYER
OF ENAMEL,AVERY HARD, HIGHLY
MINERALISEDTISSUE,WHICH IS DERIVED
FROM ECTODERM.