a layer of microcrystalline and organic particle debris that remains on the hard tissues of the teeth whenever they are cut. It may be important in assisting or preventing the penetration of bacteria into the dentinal tubules. The success of root canal treatment depends on the complete removal of the smear layer with a *chelating agent such as EDTA, but its presence may be useful in restorative dentistry.
This screening test detects abnormal changes in the cells of the cervix (see CERVIX UTERI), enabling an affected woman to have early treatment. The National Health Service has arrangements to check women regularly. A woman’s ?rst test should be within six months of her ?rst experience of intercourse and thereafter at three-yearly intervals for the rest of her life. The test is simple, with some cells being scraped o? the cervix with a spatula and the tissue then being examined microscopically.... cervical smear
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