Newly erupted teeth is covered by:

Ref. Gray’s anatomy.  41st edition. Page. 520 NASMYTH’S MEMBRANE Covers newly erupted tooth. Membrane replaced by pellicle. Microbes invade pellicle to form plaque. ENAMEL PEARLS  Occasionally found on root surface towards cervical margin. Importance: Predisposed to plaque accumulation following gingival recession. Perikymata  Transverse wave like grooves appear to be the external manifestations of external manifestations of striae of retziusstriae of retzius. Seen in freshly erupted teeth or in tooth which is not subjected to abrasive forces.not subjected to abrasive force Average of 30 perikymata/mm in cervical regionin cervical region and 10/mm in occlusal region These may contribute to adherance of plaque material which results in caries.